Electrical Rooms
Remake batch 26: rewritten from scratch under the authoring cheatsheet with datasheet constraints; neighbors re-pointed to the new scope boundaries; the electrical code is now the adopted-electrical-code project fact
Showing changes from Rev 7
to Rev 8
in Electrical Rooms.
---
title: Electrical Rooms
category: Electrical
−toc_depth: 3
description: >
− When to use: Dedicated indoor electrical rooms and closets housing service entrance equipment, distribution switchgear, switchboards, panelboards, motor control centers, dry-type transformers, automatic transfer switches, indoor standby generators or paralleling switchgear, DC battery systems, and the associated grounding, raceway, and control infrastructure for commercial, institutional, healthcare, higher-education, data center, and industrial buildings. Covers working clearances, dedicated electrical space, headroom, door and egress arrangement, fire-resistance ratings of enclosing assemblies, ventilation and cooling for equipment heat rejection, room illumination, convenience power, drainage and plumbing restrictions, security and access control, equipment anchorage, finishes, and signage.
− Not intended for: Telecommunications and IDF rooms, which have their own bonding, grounding, and cable-management requirements (see [[sync/telecommunications-bonding]]); exterior pad-mounted equipment vaults and utility-owned substation enclosures; outdoor generator yards and fuel-storage rooms; liquid-filled transformer vaults governed by NEC 450.42 as a separate scope; equipment rooms whose primary content is information technology equipment under NEC Article 645 (the IT space may still require an adjacent electrical room built to this standard). Where multiple scopes coexist in one room, the most stringent requirement governs.
+ When to use: The dedicated indoor electrical room and the electrical closet as a space: the room that houses service equipment, switchgear, switchboards, panelboards, motor control centers, dry-type transformers, transfer switches, drives, UPS modules, control-power batteries and the open or paralleling generator sets installed indoors. Covers the working space and the dedicated electrical space the adopted electrical code requires about the equipment, headroom, the number of entrances, door swing, clear opening and panic hardware, locking and free egress, the fire-resistance rating of the enclosing construction where a code sets one, the exclusion of piping and ductwork foreign to the electrical installation, water protection at the door and on the floor, the heat-release basis and the ventilation or cooling performance the room has to deliver, the temperature and humidity limits taken from the equipment ratings, illumination and emergency illumination of the working space, the convenience receptacle, housekeeping pad provision, floor finish, the room ground bar, the signs on the room door, the coordination drawing that proves every clearance before the room is framed, and the field verification before the room is closed in and before equipment is set.
+ Not intended for: The equipment inside the room, each item of which has its own standard ([[sync/low-voltage-switchgear]], [[sync/low-voltage-switchboards]], [[sync/panelboards]], [[sync/motor-control-centers]], [[sync/low-voltage-dry-type-transformers]], [[sync/automatic-transfer-switches]], [[sync/medium-voltage-switchgear]], [[sync/medium-voltage-transformers]], [[sync/secondary-unit-substations]], [[sync/dc-battery-systems]], [[sync/uninterruptible-power-supply-systems]], [[sync/generators]], [[sync/generator-paralleling-switchgear]]); the hydrogen ventilation rate, hydrogen detection and spill containment of a battery room ([[sync/dc-battery-systems]], [[sync/battery-energy-storage-systems]]); the vault a liquid-filled transformer requires under NFPA 70 Article 450 Part III ([[sync/medium-voltage-transformers]]); telecommunications rooms and their pathways ([[sync/telecommunications-rooms-and-pathways]]) and telecommunications bonding ([[sync/telecommunications-bonding]]); the housekeeping pad as a structure ([[sync/concrete-pads]]); the design number, construction and firestopping of the rated assemblies ([[sync/fire-rated-wall-and-floor-assemblies]], [[sync/gypsum-board-assemblies]], [[sync/unit-masonry]], [[sync/firestopping]]); the doors, frames and finish hardware as products ([[sync/doors-frames-and-hardware]], [[sync/door-hardware]]) and the access control system on the door ([[sync/access-control-systems]]); the fans, louvers, dampers, ductwork, cooling units and heaters that condition the room ([[sync/hvac-fans]], [[sync/louvers-and-dampers]], [[sync/hvac-ductwork]], [[sync/split-system-air-conditioners]], [[sync/fan-coil-units]], [[sync/computer-room-air-conditioning]], [[sync/unit-heaters]]); fire suppression of the room ([[sync/wet-pipe-fire-sprinkler-systems]], [[sync/pre-action-and-deluge-sprinkler-systems]], [[sync/clean-agent-fire-suppression]]); the luminaires, emergency luminaires, control devices and receptacles as products ([[sync/lighting-fixtures]], [[sync/emergency-and-egress-lighting]], [[sync/lighting-controls]], [[sync/wiring-devices]]); the nameplates and arc-flash labels on the equipment ([[sync/equipment-labeling]]) and the exit marking of the building ([[sync/signage-and-egress-markings]]); the grounding electrode system and the sizing of bonding conductors ([[sync/grounding-and-bonding]]); raceways and busway entering the room ([[sync/raceways-and-conduit]], [[sync/busway]]); the seismic anchorage design of the equipment ([[sync/vibration-isolation-and-seismic-restraint]]); outdoor equipment yards, utility-owned substations and vaults, and information technology equipment rooms under NFPA 70 Article 645, which no SynC standard yet owns.
---
# Scope {toc}
−## This standard governs the design and construction of dedicated electrical rooms and closets — the rooms that house service entrance equipment, distribution switchgear, switchboards, panelboards, motor control centers, dry-type transformers, automatic transfer switches, indoor standby generators or paralleling switchgear, DC battery systems, and the raceway, grounding, and control infrastructure that connects them. {note}
−## The electrical room is not a piece of equipment; it is the envelope, the working environment, and the access regime that allow the equipment inside it to be installed safely, maintained safely, and operated for its full service life. {note}
+## This standard governs the electrical room as a space: the envelope, the clearances, the entrances, the environment and the services that let the equipment inside it be installed, operated and maintained safely for the life of the building. Every item of equipment in the room has its own standard that assumes the room satisfies this one, so this standard never selects, rates or describes the equipment; it describes what the room owes the equipment. {note}
−## The room is regulated by two overlapping bodies of code. {note}
−## NFPA 70 (the National Electrical Code) sets the working space, dedicated equipment space, egress, illumination, and access requirements that apply to the equipment as installed, principally in Article 110.26 for installations 1000 V and below and in Articles 110.31 through 110.34 for installations over 1000 V. The International Building Code sets the fire-resistance ratings, occupancy classification, structural support, and means-of-egress requirements that apply to the room as a building element, principally in Chapters 5 through 10 and in Section 304 for utility occupancy. {note}
+## The engineer decides the room type, the basis for the working space depth beyond what the adopted electrical code requires, whether the working space is marked on the floor, whether piping foreign to the electrical installation is tolerated anywhere in the room, the door clear opening and the panic hardware and locking policy, the water protection at the door and on the floor, the heat-release basis and the heat rejection method, the temperature and humidity limits, the condition monitoring, the illumination level and its control, the emergency illumination source, the convenience receptacle provision, the housekeeping pad provision and the floor finish, the room ground bar, the signs on the door and the field verification performed. The number of entrances follows from the equipment rating, the fire-resistance rating follows from the code analysis, and the upper temperature limit follows from the equipment ratings; this standard records those rather than choosing them. {note}
−## Where the contract documents, the adopted building code, the adopted electrical code, or a referenced standard impose differing requirements, the more stringent shall govern unless the Engineer of Record directs otherwise in writing.
+## Two bodies of code shape the room. [[parameter: adopted-electrical-code]] fixes the working space, the dedicated electrical space, the entrances, the illumination and the control of access about the equipment as installed, in NFPA 70 110.26 for equipment rated 1000 V and below and in 110.31 through 110.34 for equipment rated over 1000 V. [[parameter: adopted-building-code]] fixes the fire-resistance rating of the enclosing construction, the occupancy, the structural support and the means of egress that apply to the room as a building element. Where the two overlap, the room satisfies both. {note}
−## The Contractor and the design team shall treat this standard as setting the room conditions that the equipment specifications assume.
+## The following are governed elsewhere and are outside this standard: {note}
−## The working space, headroom, ventilation, illumination, and grounding requirements stated here support the proper installation and operation of equipment specified in [[sync/low-voltage-switchgear]], [[sync/low-voltage-switchboards]], [[sync/panelboards]], [[sync/medium-voltage-switchgear]], [[sync/motor-control-centers]], [[sync/low-voltage-dry-type-transformers]], [[sync/medium-voltage-transformers]], [[sync/automatic-transfer-switches]], and [[sync/dc-battery-systems]].
+- the equipment inside the room, each item of which has its own standard ([[sync/low-voltage-switchgear]], [[sync/low-voltage-switchboards]], [[sync/panelboards]], [[sync/motor-control-centers]], [[sync/low-voltage-dry-type-transformers]], [[sync/automatic-transfer-switches]], [[sync/medium-voltage-switchgear]], [[sync/medium-voltage-transformers]], [[sync/secondary-unit-substations]], [[sync/dc-battery-systems]], [[sync/uninterruptible-power-supply-systems]], [[sync/generators]], [[sync/generator-paralleling-switchgear]])
+- the hydrogen ventilation rate, the hydrogen detection, the eyewash and the spill containment of a battery room, which [[sync/dc-battery-systems]] and [[sync/battery-energy-storage-systems]] set and which this standard requires the room to accommodate
+- the vault a liquid-filled transformer requires indoors under NFPA 70 Article 450 Part III, which [[sync/medium-voltage-transformers]] governs
+- telecommunications rooms, equipment rooms and entrance facilities and the pathways serving them ([[sync/telecommunications-rooms-and-pathways]]), and the telecommunications bonding backbone and ground bars ([[sync/telecommunications-bonding]])
+- the housekeeping pad as a structure, its height, projection, thickness, reinforcement and anchorage ([[sync/concrete-pads]])
+- the design number, construction and continuity of the rated walls, floors and ceilings ([[sync/fire-rated-wall-and-floor-assemblies]], [[sync/gypsum-board-assemblies]], [[sync/unit-masonry]]) and the firestop systems at every penetration of them ([[sync/firestopping]])
+- the doors, frames and finish hardware as products, including panic hardware, closers and locksets ([[sync/doors-frames-and-hardware]], [[sync/door-hardware]]), and the readers, controllers and door position switches of the access control system ([[sync/access-control-systems]])
+- the fans, louvers, dampers, ductwork, cooling units and heaters that condition the room ([[sync/hvac-fans]], [[sync/louvers-and-dampers]], [[sync/hvac-ductwork]], [[sync/split-system-air-conditioners]], [[sync/fan-coil-units]], [[sync/computer-room-air-conditioning]], [[sync/unit-heaters]]) and the building automation system that monitors it ([[sync/building-automation-system]])
+- the sprinkler, pre-action and clean agent systems that protect the room ([[sync/wet-pipe-fire-sprinkler-systems]], [[sync/pre-action-and-deluge-sprinkler-systems]], [[sync/clean-agent-fire-suppression]])
+- the luminaires, the emergency luminaires, the lighting control devices and the receptacles as products ([[sync/lighting-fixtures]], [[sync/emergency-and-egress-lighting]], [[sync/lighting-controls]], [[sync/wiring-devices]])
+- the nameplates, warning signs and arc-flash labels on the equipment ([[sync/equipment-labeling]]), the arc-flash study behind them ([[sync/arc-flash-study]]), and the egress signage of the building ([[sync/signage-and-egress-markings]])
+- the grounding electrode system, the bonding of the ground bar and the sizing of every bonding conductor ([[sync/grounding-and-bonding]])
+- the raceways, cable trays and busway entering and leaving the room ([[sync/raceways-and-conduit]], [[sync/busway]])
+- the seismic anchorage design of the equipment ([[sync/vibration-isolation-and-seismic-restraint]]) and the facility's energized work program ([[sync/electrical-safety-program]])
+- the total building commissioning program into which the field verification of this standard is folded ([[sync/commissioning]])
+- outdoor equipment yards, utility-owned substations and vaults, and information technology equipment rooms under NFPA 70 Article 645, which no SynC standard yet owns
−## The grounding electrode system serving the room shall comply with [[sync/grounding-and-bonding]].
+## Where one room houses both electrical and telecommunications equipment, this standard governs the electrical equipment, its working space and its dedicated electrical space, and [[sync/telecommunications-rooms-and-pathways]] governs the telecommunications equipment, its clearances and its backboards, and neither reduces the other's clearances. {note}
−## Wall, floor, and ceiling penetrations shall be sealed per [[sync/firestopping]]; the rated assemblies themselves are constructed under separate scopes coordinated with this standard.
+## The location, the plan dimensions and the equipment arrangement of each electrical room shall be as indicated on [[drawing: the electrical plans]].
−## Equipment identification and arc-flash labels shall follow [[sync/equipment-labeling]].
+## Every electrical room shall comply with [[parameter: adopted-electrical-code]] for the spaces about electrical equipment, and with [[parameter: adopted-building-code]] for its construction, its fire separation and its means of egress.
−## Raceway entering and leaving the room shall comply with [[sync/raceways-and-conduit]].
+## An electrical room shall contain no equipment other than the electrical equipment it is built for, the raceways and busway serving that equipment, and the mechanical and fire protection equipment that serves the room itself.
−## Telecommunications equipment shall not be housed in an electrical room governed by this standard except where specifically coordinated with [[sync/telecommunications-bonding]].
−
−## The telecommunications and electrical scopes have incompatible grounding and access requirements when intermixed casually. {note}
−
−## This standard does not address exterior pad-mounted equipment, utility-owned vaults, generator yards, fuel rooms, or liquid-immersed transformer vaults under NEC 450.42; those scopes are governed by their own standards and codes. {note}
−
# Referenced Standards {toc}
−## Equipment, room construction, and installation shall comply with the latest adopted edition of the following.
+## Construction and installation shall comply with the latest adopted edition of each of the following unless a specific edition is cited.
+## Where the contract documents, the Authority Having Jurisdiction, or two referenced standards impose conflicting requirements, the more stringent requirement shall govern unless the Engineer of Record directs otherwise in writing.
+
| Standard | Title |
|----------|-------|
−| NFPA 70 | National Electrical Code — Article 110.26 (Spaces About Electrical Equipment, 1000 V and below) |
−| NFPA 70 | National Electrical Code — Article 110.27 (Guarding of Live Parts) |
−| NFPA 70 | National Electrical Code — Article 110.31 (Enclosure for Electrical Installations, over 1000 V) |
−| NFPA 70 | National Electrical Code — Article 110.34 (Working Space, over 1000 V) |
−| NFPA 70 | National Electrical Code — Article 110.16 (Arc-Flash Hazard Warning) |
−| NFPA 70 | National Electrical Code — Article 210.63 (Receptacle in Service-Equipment Rooms) |
−| NFPA 70 | National Electrical Code — Article 240.24 (Location of Overcurrent Devices) |
−| NFPA 70 | National Electrical Code — Article 250 (Grounding and Bonding) |
−| NFPA 70 | National Electrical Code — Article 450.21 (Indoor Dry-Type Transformer Installation) |
−| NFPA 70 | National Electrical Code — Article 450.42 (Indoor Vault for Liquid-Insulated Transformers) |
+| NFPA 70 | National Electrical Code (Article 110, Parts II and III; 210.63; 450.21; 700.16) |
| NFPA 70E | Standard for Electrical Safety in the Workplace |
−| NFPA 75 | Standard for the Fire Protection of Information Technology Equipment (where adjacent IT space governs) |
−| NFPA 101 | Life Safety Code (egress from electrical rooms, door swing, panic hardware) |
−| IBC | International Building Code, Chapter 3 — Use and Occupancy Classification (Section 304, Business; utility classification where applicable) |
−| IBC | International Building Code, Chapter 7 — Fire and Smoke Protection Features |
−| IBC | International Building Code, Chapter 10 — Means of Egress |
−| ASTM E119 | Standard Test Methods for Fire Tests of Building Construction and Materials |
−| UL 263 | Fire Tests of Building Construction and Materials |
−| ASHRAE 90.1 | Energy Standard for Buildings (lighting power density, ventilation energy) |
−| IECC | International Energy Conservation Code (lighting and envelope) |
−| IEEE 484 | Recommended Practice for Installation Design and Installation of Vented Lead-Acid Batteries for Stationary Applications |
−| IEEE 1187 | Recommended Practice for Installation Design and Installation of Valve-Regulated Lead-Acid Batteries for Stationary Applications |
−| IEEE 1584 | Guide for Performing Arc-Flash Hazard Calculations |
−| NEMA 250 | Enclosures for Electrical Equipment (1000 V Maximum) |
−| ICC A117.1 | Accessible and Usable Buildings and Facilities (where electrical rooms are publicly accessed) |
−| ASCE 7 | Minimum Design Loads and Associated Criteria for Buildings (seismic anchorage) |
−| ICC ES AC156 | Acceptance Criteria for Seismic Certification by Shake-Table Testing |
−| ANSI/NETA ATS | Acceptance Testing Specifications for Electrical Power Equipment and Systems |
+| NFPA 101 | Life Safety Code |
+| NFPA 110 | Standard for Emergency and Standby Power Systems (Chapter 7) |
+| NFPA 80 | Standard for Fire Doors and Other Opening Protectives |
+| NFPA 13 | Standard for the Installation of Sprinkler Systems |
+| IBC | International Building Code (Chapters 7 and 10) |
+| 29 CFR 1910.303 | Occupational Safety and Health Standards, Electrical, General (working space about electric equipment) |
+| IEEE C37.20.7 | Guide for Testing Switchgear Rated Up to 52 kV for Internal Arcing Faults |
+| ANSI Z535.4 | Product Safety Signs and Labels |
+| ASHRAE 90.1 | Energy Standard for Sites and Buildings Except Low-Rise Residential Buildings |
+| IECC | International Energy Conservation Code |
# Submittals {toc}
## Action Submittals {toc}
−### The Contractor shall submit the following for the Engineer's and Architect's review prior to construction of the room and prior to procurement of room-specific products such as doors, hardware, ventilation equipment, and security devices.
+### The Contractor shall submit the following for review before the walls of any electrical room are framed and before any door, hardware or sign for the room is ordered:
−- Room layout drawings showing every equipment line-up, the required NEC 110.26 or 110.34 working space envelope around each equipment face, dedicated equipment space above and below each line-up, door swing direction and clear opening dimensions, egress paths, and any encroaching architectural, structural, mechanical, or plumbing element
−- Equipment elevations showing nameplate heights, gutter and pull-section heights, and the top-of-equipment clearance against headroom and dedicated-space requirements
−- Heat-rejection calculations for each room based on equipment nameplate losses, and the corresponding ventilation or mechanical cooling sizing, including airflow paths, intake and discharge locations, and freeze and humidity controls
−- Fire-rating coordination drawings showing the rated assemblies enclosing the room, the rating of each, and every penetration through those assemblies with the listed firestop system identified per [[sync/firestopping]]
−- Door, frame, and hardware schedule including fire rating, swing direction, panic and access-control hardware, and signage
−- Lighting layout with calculation point grid demonstrating compliance with NEC 110.26(D) and the project lighting power density limit
−- Power and receptacle plan including dedicated lighting circuit, GFCI convenience receptacles, and any non-room loads that may pass through the dedicated equipment space
−- Grounding plan showing the room ground bus, the bonding conductor from the building grounding electrode system, and bonding terminations to each equipment line-up
−- Seismic anchorage details for each piece of equipment, with the supporting structural calculations or reference to manufacturer-provided certification
−- Security and access control drawings including reader, lock, and contact locations, coordinated with [[sync/access-control-systems]]
+- the electrical room coordination drawing prepared under the Coordination Drawing section, in plan and in elevation, showing every lineup from its reviewed shop drawings, the working space and the dedicated electrical space about each, the entrances, the door swings and clear openings, the housekeeping pads, the lighting, the receptacles, the ground bar, every raceway, busway, pipe and duct that enters or crosses the room, and the egress path from the working space
+- the room heat-release schedule prepared under the Room Environment section, listing every item of equipment in the room with its heat release at the heat-release basis selected in the datasheet
+- the door schedule for every electrical room door, giving the clear opening, the swing, the fire rating, the panic hardware and the locking provision
+- the illumination calculation for the working space of each room, showing the maintained illuminance at the working plane and the luminaire locations against the dedicated electrical space
+- the schedule and artwork of the signs on each room door
```datasheet
−label: Action Submittals Required
+label: Action Submittals
type: checkbox
options:
− - "Room layout drawings (working space, dedicated space, egress)"
− - "Equipment elevations and headroom verification"
− - "Heat-rejection and ventilation/cooling calculations"
− - "Fire-rating coordination drawings with firestop system schedule"
− - "Door, frame, and hardware schedule"
− - "Lighting layout and calculations"
− - "Power and receptacle plan"
− - "Grounding plan and bonding conductor schedule"
− - "Seismic anchorage details and calculations"
− - "Security and access control drawings"
+ - "Electrical room coordination drawing in plan and elevation"
+ - "Room heat-release schedule"
+ - "Electrical room door schedule"
+ - "Working space illumination calculation"
+ - "Room door sign schedule and artwork"
default:
− - "Room layout drawings (working space, dedicated space, egress)"
− - "Equipment elevations and headroom verification"
− - "Heat-rejection and ventilation/cooling calculations"
− - "Fire-rating coordination drawings with firestop system schedule"
− - "Door, frame, and hardware schedule"
− - "Lighting layout and calculations"
− - "Power and receptacle plan"
− - "Grounding plan and bonding conductor schedule"
− - "Seismic anchorage details and calculations"
− - "Security and access control drawings"
+ - "Electrical room coordination drawing in plan and elevation"
+ - "Room heat-release schedule"
+ - "Electrical room door schedule"
+ - "Working space illumination calculation"
+ - "Room door sign schedule and artwork"
+constraint: all_of
```
−### Construction of any portion of the room shall not proceed until the corresponding submittals have been reviewed and returned.
+### The walls of an electrical room shall not be framed, and its doors, hardware and signs shall not be ordered, until the action submittals covering that room have been reviewed and returned.
−## Closeout Submittals {toc}
+## Informational Submittals {toc}
−### The Contractor shall provide the following at substantial completion:
+### The Contractor shall submit the following with or before the action submittals:
−- As-built room layout, lighting, power, grounding, and ventilation drawings reflecting field conditions
−- Field test reports for the room ground bus, working-space verification, illumination measurements, and ventilation airflow per the project commissioning plan
−- Operation and maintenance instructions for room-resident systems that are not covered by equipment-specific O&M (door hardware, ventilation, dampers, drainage)
−- Warranty documentation for room-specific products
+- the reviewed shop drawing of each item of equipment from which the coordination drawing takes its dimensions, its weight, its heat release and its ventilation clearances
+- the exhaust plenum and discharge detail of any arc-resistant switchgear in the room, as reviewed under the standard for that switchgear
+- the room ventilation or cooling calculation prepared by the trade responsible for it, showing that the room holds the temperature limits of the datasheet with every item of equipment at the heat-release basis and with outdoor air at [[parameter: site-ambient-temperature-maximum]]
+- the field verification plan for the room, naming the person who performs each verification and the instrument used
```datasheet
−label: Required Closeout Submittals
+label: Informational Submittals
type: checkbox
options:
− - "As-built room layout, lighting, power, grounding, ventilation drawings"
− - "Field test reports (ground bus, working space, illumination, airflow)"
− - "O&M instructions for room-resident systems"
− - "Warranty documentation for room-specific products"
+ - "Reviewed equipment shop drawings used by the coordination drawing"
+ - "Arc-resistant switchgear exhaust plenum and discharge detail"
+ - "Room ventilation or cooling calculation"
+ - "Field verification plan"
default:
− - "As-built room layout, lighting, power, grounding, ventilation drawings"
− - "Field test reports (ground bus, working space, illumination, airflow)"
− - "O&M instructions for room-resident systems"
− - "Warranty documentation for room-specific products"
+ - "Reviewed equipment shop drawings used by the coordination drawing"
+ - "Room ventilation or cooling calculation"
+ - "Field verification plan"
+constraint: all_of
```
−# Quality Assurance {toc}
+## Closeout Submittals {toc}
−## Coordination Authority {toc}
+### The Contractor shall submit the following before the equipment in the room is energized for other than testing:
−### The electrical room is the single most heavily coordinated space in the building. {note}
+- the record coordination drawing of each room, revised to the as-built positions of the equipment, the pads, the doors, the luminaires, the receptacles, the ground bar and every foreign system in the room
+- the field verification report of each room, recording every measurement the Field Verification section requires with the date and the person who took it
+- the as-built door schedule and sign schedule for each room
+- the room heat-release schedule revised to the equipment actually installed
−### The electrical Contractor shall hold a coordination meeting before construction of any electrical room is permitted to proceed beyond rough framing, with the General Contractor, the mechanical and plumbing trades, the structural trade, the fire-protection trade, and the architect of record.
+```datasheet
+label: Closeout Submittals
+type: checkbox
+options:
+ - "Record coordination drawing"
+ - "Field verification report"
+ - "As-built door and sign schedules"
+ - "As-built room heat-release schedule"
+default:
+ - "Record coordination drawing"
+ - "Field verification report"
+ - "As-built door and sign schedules"
+ - "As-built room heat-release schedule"
+constraint: all_of
+```
−### The coordination meeting agenda shall include working-space envelopes, dedicated electrical space, fire-rated boundaries, penetration locations, ventilation routing, drainage path (where any drainage is present at all), and the routing of all conduit, piping, and ductwork that crosses the room.
+# Quality Assurance {toc}
−### The coordination meeting minutes shall be incorporated into the project record.
+## Coordination Responsibility {toc}
−## Regulatory Inspection {toc}
+### The electrical Contractor shall prepare the coordination drawing and shall hold a coordination meeting for each electrical room, attended by the General Contractor and by the mechanical, plumbing, fire protection, structural and architectural trades, before the walls of that room are framed.
−### Working space, dedicated electrical space, working-space illumination, egress arrangement, and the location of overcurrent devices shall be available for inspection by the Authority Having Jurisdiction before the room is closed up with finishes or before equipment installation reaches a state where the room conditions cannot be measured.
+### The coordination meeting shall settle the working space and dedicated electrical space about each lineup, the routing of every pipe, duct and raceway that enters or crosses the room, the pad locations, the door swings, the louver and duct penetrations of the rated enclosure and the egress path, and its minutes shall be issued to every attending trade.
−### The Contractor shall not conceal any portion of the rated wall, floor, or ceiling assemblies until firestop and assembly inspections have been completed and released.
+### A conflict found at the coordination meeting shall be resolved before the walls are framed, and where no other resolution exists the working space, the dedicated electrical space and the entrances required by [[parameter: adopted-electrical-code]] shall govern, because they are code minimums while the routing of other trades is adjustable.
−## Listed and Labeled Components {toc}
+### Every trade that penetrates or crosses an electrical room is a candidate to violate a clearance that only the electrical trade is measured against, and the clearances cannot be bought back after the slab is poured and the duct is hung. A coordination drawing that every trade has reviewed before framing is the one instrument that puts the clearance in front of the trade that would otherwise occupy it. {note}
−### All firestop systems, fire-rated doors and frames, fire dampers, ventilation equipment, lighting fixtures, and electrical room receptacles and circuits shall be listed and labeled by a Nationally Recognized Testing Laboratory for the application.
+## Authority Having Jurisdiction Inspection {toc}
−### Substitution of unlisted products is not permitted in any rated assembly or in any application where the listing is part of the basis of design.
+### The working space, the dedicated electrical space, the entrances and the illumination of each room shall be left open to inspection by the Authority Having Jurisdiction after the equipment is set and before any ceiling, finish or foreign system conceals them.
−# Environmental and Service Conditions {toc}
+### The Contractor shall not conceal a rated wall, floor or ceiling of the room until the inspection of the assembly and of its firestopping required under [[sync/fire-rated-wall-and-floor-assemblies]] and [[sync/firestopping]] has been completed and released.
−## Electrical rooms shall provide a controlled environment so that equipment operates within its nameplate ratings, so that insulation systems and electronics retain their service life, and so that operations and maintenance work is performable safely.
+## Qualified Persons {toc}
−## The Engineer shall establish the project design conditions for each room, and shall adjust them where the connected equipment or the local climate requires it.
+### Access to an electrical room shall be limited to qualified persons as [[parameter: adopted-electrical-code]] and NFPA 70E define them and to the persons the Owner authorizes in writing, and the room door shall be kept locked when no qualified person is in the room.
−## Temperature {toc}
+# Room Type and Location {toc}
−### The room cooling setpoint and the room minimum heating temperature shall be as indicated in the datasheet.
+## The type of space this standard is applied to shall be as indicated in the datasheet.
```datasheet
−label: Room Ambient Setpoint (Cooling)
−type: range
−unit: °F
+label: Room Type
+type: select
options:
− min: 65
− max: 90
− step: 1
−default: 75
+ - "Dedicated electrical room"
+ - "Electrical closet"
+ - "Electrical equipment area within a mechanical or other equipment room"
```
−```datasheet
−label: Room Minimum Temperature (Heating)
−type: range
−unit: °F
−options:
− min: 40
− max: 70
− step: 1
−default: 60
−```
+## A dedicated electrical room is enclosed by its own walls and door and holds nothing but electrical equipment, so its working space, its dedicated electrical space and its environment are under the control of one trade, at the cost of floor area and of a separate ventilation or cooling provision. An electrical closet is the small room, usually serving one floor, that holds a panelboard, a transformer and a few disconnects behind a single door; it buys the least floor area and leaves the equipment to reject its losses into the corridor air or a transfer grille, which limits how much heat the closet can hold. An electrical equipment area inside a mechanical room buys the least construction of all and shares its ventilation, at the cost of the piping, ductwork and other trades' working space that the mechanical room exists for, every one of which has to be routed around the dedicated electrical space. Which type a project uses follows from the size and heat release of the equipment and from the floor area the building has to give. {note}
−### A 75 °F cooling setpoint is the most common selection for rooms housing typical low-voltage distribution and dry-type transformers and provides margin against equipment derating during summer peak. {note}
+## Every room type carries the same working space, dedicated electrical space, entrance, illumination and access requirements, and the difference between the three is what else occupies the space and who conditions it. {note}
−### Rooms housing battery systems shall be maintained at 77 °F ± 5 °F to maximize battery service life.
+## An electrical room shall not be located directly beneath a space containing plumbing fixtures, floor drains, cooling towers, roof drains or water-filled equipment unless the floor above is waterproofed and the Engineer of Record accepts the location in writing.
−### Rooms housing equipment rated for 40 °C ambient with no derating may be allowed to drift higher, but the equipment specifier shall confirm that the connected loads, fault levels, and harmonic content do not push the equipment outside its derated capability before allowing a higher setpoint.
+## An electrical room containing service equipment, the equipment of an emergency or legally required standby system, or a fire pump controller shall have its finished floor above the design flood elevation indicated on [[drawing: the civil drawings]] where the site lies in a flood hazard area.
−### A heating setpoint shall be provided wherever the room can drop below the dew point of the surrounding spaces or below the minimum operating temperature of any installed equipment.
+## A room whose floor is below the adjacent exterior grade shall be protected against groundwater and surface water by the waterproofing and subdrainage of the building, and the room shall not be the low point of the drainage system of the floor it stands on.
−### Battery rooms, rooms with electronic protective relays, and rooms with VFDs have higher minimum temperatures than rooms with mechanical-only equipment. {note}
+## A room housing equipment rated over 1000 V shall be enclosed by walls, screens or a fence that make it accessible to qualified persons only, with its door locked or under continuous observation, in accordance with NFPA 70 110.31.
−## Humidity {toc}
+## A room that houses an open generator set, a control-power battery or an energy storage system shall provide the fire separation, the ventilation openings, the floor containment and the ignition source control that [[sync/generators]], [[sync/dc-battery-systems]] and [[sync/battery-energy-storage-systems]] require of it, and nothing in this standard reduces what those standards demand of the room.
−### The maximum room relative humidity shall be as indicated in the datasheet.
+# Working Space {toc}
−```datasheet
−label: Room Relative Humidity (Maximum)
−type: range
−unit: '%'
−options:
− min: 50
− max: 95
− setpoints: [50, 60, 70, 80, 85, 95]
−default: 80
−```
+## Working Space Depth {toc}
−### Relative humidity in electrical rooms shall be controlled to limit condensation on energized parts, corrosion of bus and connections, and degradation of insulation systems.
+### The basis for the depth of the working space in front of each lineup shall be as indicated in the datasheet.
−### Equipment rated for indoor use is generally suitable for non-condensing conditions; condensing conditions are not acceptable in any electrical room governed by this standard.
−
−### Where the room is mechanically conditioned with the rest of the building, the humidity is normally controlled by the central system. {note}
−
−### Where the room is conditioned only by exhaust ventilation, humidity may rise during humid weather and the Engineer shall confirm that the connected equipment is rated for non-condensing operation at the worst-case dew point of the supplied air.
−
−## Particulates and Atmospheric Contaminants {toc}
−
−### The filtration provided on the air supplied to the room shall be as indicated in the datasheet.
−
```datasheet
−label: Room Air Filtration
−type: select
+label: Working Space Depth Basis
+type: radio
options:
− - "No dedicated filtration — building HVAC serves room"
− - "MERV 8 minimum at room supply"
− - "MERV 11 (industrial or loading-adjacent)"
− - "MERV 13 or higher (data center adjacent or sensitive environments)"
+ - "The depth NFPA 70 Table 110.26(A)(1) requires for the voltage to ground and the condition at each lineup"
+ - "The Condition 3 depth of NFPA 70 Table 110.26(A)(1) at every lineup"
+ - "Twice the depth NFPA 70 Table 110.26(A)(1) requires at every lineup"
+default: "The depth NFPA 70 Table 110.26(A)(1) requires for the voltage to ground and the condition at each lineup"
```
−### The required filtration follows from the adjacencies of the specific room, which the Engineer assesses per project; no filtration level is correct for every electrical room, so the field carries no default. {note}
+### The table sets the depth by the voltage to ground and by what faces the worker across the space: Condition 1 has exposed live parts on one side and nothing live or grounded on the other, Condition 2 has a grounded surface opposite, which a concrete, masonry or tile wall is taken to be, and Condition 3 has exposed live parts on both sides. At the 277 V to ground of a 480Y/277 V system the three conditions call for 3 ft, 3 ft 6 in. and 4 ft. The table depth is the floor on which most rooms are laid out and costs the least floor area. The Condition 3 depth at every lineup removes the argument about what faces the equipment and keeps a later lineup on the facing wall from shrinking the space, at the cost of floor area in every room. Twice the table depth is the provision under which NFPA 70 110.26(C)(2) permits a single entrance to a room that would otherwise need one at each end, and it is chosen where a second door cannot be had or where drawout breakers and lift trucks need the room to maneuver. {note}
−### Electrical rooms shall be constructed so that airborne particulates, combustion products, vehicle exhaust, and corrosive vapors do not enter the room from adjacent occupancies.
+### The depth of the working space shall be measured from the exposed live parts where they are exposed, or from the front of the enclosure or its opening where the parts are enclosed, and shall be clear over the full width and height of the working space.
−### Where the room is adjacent to a loading dock, a kitchen, a parking garage, a chemical-storage area, or any space with elevated particulate or corrosive loading, the air supply to the electrical room shall be drawn from a cleaner location and filtered as required.
+### Where two lineups face each other across one space, the space between them shall satisfy the Condition 3 depth at the higher voltage to ground present, measured between the enclosure faces.
−# Working Space {toc}
+### The working space in front of a lineup shall not overlap the working space of equipment on a perpendicular wall unless both spaces remain clear over their full depth, width and height.
−## The unobstructed working space in front of, and where applicable behind and beside, energized electrical equipment is the single most heavily enforced provision of NEC Article 110. {note}
+### Where equipment rated over 1000 V is installed, the working space depth shall be the depth NFPA 70 Table 110.34(A) requires for its voltage and condition, and the datasheet basis above shall apply to that table in place of Table 110.26(A)(1).
−## Working space exists to allow examination, adjustment, servicing, and maintenance of equipment under energized conditions; it shall be kept clear at all times during the life of the building and shall not be used for storage, routing of unrelated trades, or any non-electrical purpose.
+## Working Space Width and Height {toc}
−## Depth of Working Space — 1000 V and Below {toc}
+### The width of the working space in front of each lineup shall be the width of the equipment or 30 in., whichever is greater, and shall permit every door and hinged cover of the equipment to open at least 90 degrees, in accordance with NFPA 70 110.26(A)(2).
−### NEC 110.26(A)(1) establishes three conditions for the depth of working space in front of equipment likely to require examination, adjustment, servicing, or maintenance while energized. {note}
−### The conditions are based on what is on the opposite side of the working space. {note}
+### The height of the working space shall be 6 ft 6 in. or the height of the equipment, whichever is greater, measured from the floor or from the platform the worker stands on, in accordance with NFPA 70 110.26(A)(3).
−- Condition 1: Exposed live parts on one side of the working space and no live or grounded parts on the other side, or exposed live parts on both sides effectively guarded by insulating material
−- Condition 2: Exposed live parts on one side and grounded parts on the other side (concrete, brick, tile walls are considered grounded)
−- Condition 3: Exposed live parts on both sides of the working space, not guarded by insulating material, with the operator between
+### No luminaire, raceway, pipe, duct, structural member or other equipment shall intrude into the working space over its full depth, width and height, except the equipment's own enclosure extensions that NFPA 70 110.26(A)(3) permits to extend not more than 6 in. beyond the front of the equipment.
−### Working space depth is then determined by the nominal voltage to ground and the governing condition. {note}
−### For installations 151 V to 600 V to ground (the dominant case for 277/480 V systems with neutral grounded), Condition 1 requires 3 ft, Condition 2 requires 3 ft 6 in., and Condition 3 requires 4 ft. {note}
−### For installations 0 V to 150 V to ground, all conditions require 3 ft. {note}
−### For installations 601 V to 2500 V, Condition 1 requires 3 ft, Condition 2 requires 4 ft, and Condition 3 requires 5 ft. {note}
+### Switchgear, switchboards and motor control centers are commonly 90 in. to 96 in. tall, so in a room that holds them the working space height is set by the equipment and not by the 6 ft 6 in. floor, and a lift truck with its mast raised to the top compartment needs more than either. {note}
−### The full table at NEC 110.26(A)(1) shall be consulted for any voltage class not listed above.
+### Where a lineup is served by a breaker lift truck or a drawout ramp, the working space shall admit the truck in front of every compartment with its mast raised to the highest compartment, on a level surface, as the standard for that lineup requires.
−### The working space condition governing each equipment line-up shall be as indicated in the datasheet.
+## Working Space Preservation {toc}
+### The working space shall be kept clear for the life of the building and shall not be used for storage, for the working space of mechanical or plumbing equipment, or for any purpose other than access to the electrical equipment.
+
+### Whether the working space is marked on the floor shall be as indicated in the datasheet.
+
```datasheet
−label: Working Space Condition Governing Room Layout
+label: Working Space Floor Marking
type: radio
−drawing_ref: "electrical room layout drawings"
options:
− - "Condition 1 — exposed parts on one side, no live or grounded parts opposite"
− - "Condition 2 — exposed parts opposite a grounded surface"
− - "Condition 3 — exposed parts on both sides, operator between"
−default: deferred
+ - "Painted or taped outline of the working space on the floor in front of every lineup"
+ - "None"
```
−### Working space depth shall not be less than the value required by NEC 110.26(A)(1) for the nominal voltage to ground and the governing condition.
+### A painted outline costs a few hours of layout and paint and gives a facility a line that a stored pallet or a later piece of equipment visibly crosses, which is how the working space survives the first decade of occupancy; no outline leaves the clearance to the memory of whoever reads the record drawings. Where the floor is a resinous finish, the outline is applied under that finish's standard so the two coatings are compatible. {note}
−### The working space depth provided in the room layout shall be as indicated in the datasheet.
+### Where the floor marking is selected, the outline shall be laid out from the as-built enclosure faces at the depth and width the datasheet basis requires, and shall be shown on the record coordination drawing.
−```datasheet
−label: Working Space Depth in Front of Equipment
−type: range
−unit: ft
−options:
− min: 3
− max: 6
− setpoints: [3, 3.5, 4, 5, 6]
−```
+# Dedicated Electrical Space {toc}
−### The NEC 110.26(A)(1) table sets a floor, not a target; the depth actually provided is a room-design decision and is frequently made deeper than the code minimum to suit draw-out equipment, maintenance practice, or an Owner standard, so the field carries no default. {note}
+## Space Above and Below the Equipment {toc}
−### The working space envelope for each equipment line-up shall be shown dimensioned from the equipment face [[drawing: on the electrical room layouts]].
+### The space equal to the width and depth of each lineup, from the floor to 6 ft above the equipment or to the structural ceiling where that is lower, shall be dedicated to the electrical installation, in accordance with NFPA 70 110.26(E)(1)(a).
−### Where two facing equipment line-ups create a Condition 3 situation, both shall be served by a single working space measured between the equipment faces, sized for Condition 3 at the higher voltage class present.
+### No piping, duct, leak protection apparatus or other equipment foreign to the electrical installation shall be installed in or pass through the dedicated electrical space.
−### The working space shall not be shared with the working space of equipment on a perpendicular wall except where physically possible without obstruction.
+### A suspended, dropped or similar ceiling that does not add strength to the building structure shall not be treated as the structural ceiling for the purpose of the dedicated electrical space, in accordance with NFPA 70 110.26(E)(1)(d).
−## Width and Height of Working Space {toc}
+### The dedicated space is the volume the electrical trade needs for the raceways, the busway and the cable entries that rise out of or drop into the equipment, and it is the volume every other trade finds convenient for a main, because it runs along the wall above a row of enclosures no one else occupies. The 6 ft above the equipment is not free ceiling plenum, and a ceiling hung below structure does not shorten it. {note}
−### The width of the working space is fixed by NEC 110.26(A)(2) as a function of the equipment dimensions, so it is not offered as a datasheet selection. {note}
+### The clear height of each room from the finished floor to the underside of the structure shall be not less than the height of the tallest lineup plus 6 ft, and not less than the height the lift truck, the arc-resistant exhaust plenum or the top conduit entries of any lineup require, and shall be as indicated on [[drawing: the electrical room coordination drawing]].
−### Per NEC 110.26(A)(2), the width of working space in front of electrical equipment shall be the width of the equipment or 30 in., whichever is greater.
+## Foreign Systems Above the Dedicated Space {toc}
−### The working space shall permit at least a 90-degree opening of equipment doors or hinged panels, in accordance with NEC 110.26(A)(2).
+### Where the structural ceiling is more than 6 ft above the equipment, a system foreign to the electrical installation shall be permitted above the dedicated electrical space only where protection is installed below it that prevents a leak, condensation or a break in that system from reaching the equipment, in accordance with NFPA 70 110.26(E)(1)(b).
−### Per NEC 110.26(A)(3), the height of working space shall be 6 ft 6 in., or the height of the equipment, whichever is greater.
+### The protection below a foreign system shall be a drip shield or pan of sheet metal or rigid plastic, sloped and drained to a point outside the dedicated electrical space and the working space, and shall extend not less than 6 in. beyond the system it protects on every side.
−### The 6 ft 6 in. minimum is measured from the floor or platform; equipment, raceway, piping, lighting fixtures, and HVAC components shall not encroach on this volume.
+## Arc Exhaust Discharge {toc}
−### Switchgear, motor control centers, and switchboards routinely exceed 6 ft 6 in., so the working space height in rooms containing them is set by the equipment rather than by the 6 ft 6 in. floor. {note}
+### Where the room houses arc-resistant switchgear, the room shall provide the exhaust plenum path and the discharge location shown on the reviewed shop drawings of that switchgear, discharging to the outdoors or to a space in which no person stands, and the plenum shall not reduce the dedicated electrical space of any other lineup.
−### The working space headroom provided in the room design shall be as indicated in the datasheet.
+### Where the plenum discharges through a rated wall or into a duct, the penetration shall be firestopped under [[sync/firestopping]] and the duct shall be of the construction and the pressure rating the switchgear manufacturer requires for the arc exhaust.
−```datasheet
−label: Working Space Headroom (Minimum)
−type: range
−unit: ft
−options:
− min: 6.5
− max: 10
− setpoints: [6.5, 7, 8, 9, 10]
−```
+### An arc-resistant lineup directs the products of an internal fault through a plenum to a point where no worker stands, and the rating applies only when that path exists and is clear. The switchgear standard tests and rates the plenum; the room has to give it somewhere to go. {note}
−### NEC 110.26(A)(3) sets the floor at 6 ft 6 in. or the height of the equipment, whichever is greater; the datasheet records the headroom actually provided, which is routinely taken higher where equipment lifting, cable pulling, or an Owner standard requires it, so the field carries no default. {note}
+# Entrances and Egress {toc}
−## Working Space — Over 1000 V {toc}
+## Number of Entrances {toc}
−### For equipment rated over 1000 V, NEC 110.34 establishes a separate working space table with greater clearances and additional rules. {note}
−### For 1001 V to 2500 V, Condition 1 requires 3 ft, Condition 2 requires 4 ft, and Condition 3 requires 5 ft. {note}
−### For 2501 V to 9000 V, Condition 1 requires 4 ft, Condition 2 requires 5 ft, and Condition 3 requires 6 ft. {note}
+### The number of entrances to the working space of each room shall be as indicated in the datasheet.
−### The full working space table at NEC 110.34(A) shall govern any installation over 1000 V.
+```datasheet
+label: Number of Entrances to the Working Space
+type: radio
+derived: "the ampere rating and the width of the equipment in the room and the exceptions of NFPA 70 110.26(C)(2) and 110.33(A)"
+options:
+ - "One entrance"
+ - "Two entrances, one at each end of the working space"
+default: derived
+```
−### Working space over 1000 V shall be guarded per NEC 110.31.
+### Where the room contains equipment rated 800 A or more and over 6 ft wide that holds overcurrent, switching or control devices, there shall be an entrance not less than 24 in. wide and 6 ft 6 in. high at each end of the working space, in accordance with NFPA 70 110.26(C)(2), unless the room satisfies one of the exceptions that section permits.
−### Access to working space over 1000 V shall be permitted only to qualified persons, and the room shall be equipped with the entrance and egress provisions of NEC 110.33.
+### A single entrance shall be permitted to such a room only where the location permits a continuous and unobstructed way of egress from the working space, or where the working space depth is twice that NFPA 70 Table 110.26(A)(1) requires and the entrance is at least that doubled depth from the equipment, so that a worker can move away from the equipment in either direction.
−# Headroom and Equipment Height {toc}
+### Where the room contains equipment rated over 1000 V, the entrances shall satisfy NFPA 70 110.33(A), with an entrance at each end of any switchgear or control assembly over 6 ft wide unless an exception that section permits applies.
−## This is a clear-volume requirement, not a finished-ceiling dimension. {note}
+### The one-entrance rule and the two-entrance rule both exist so that a worker who has an arcing fault in front of them has a way out that does not pass the fault. The second door costs a door, a frame, hardware and a wall opening; the doubled depth costs floor area along the whole lineup; the unobstructed egress exception costs nothing but is available only where the room's shape gives it. {note}
−## The room clear height, measured from finished floor to the underside of structure, shall be as indicated in the datasheet.
+### The door clear opening width of each entrance shall be as indicated in the datasheet.
```datasheet
−label: Finished Floor to Underside of Structure (Room Clear Height)
+label: Door Clear Opening Width
type: range
−unit: ft
−drawing_ref: "electrical room layout drawings"
+unit: in
+drawing_ref: "the electrical room coordination drawing"
options:
− min: 9
− max: 16
− setpoints: [9, 10, 11, 12, 14, 16]
+ min: 32
+ max: 96
+ setpoints: [32, 36, 42, 48, 60, 72, 84, 96]
default: deferred
+constraint: min
```
−## Per NEC 110.26(A)(3), the minimum headroom of working spaces about service equipment, switchboards, panelboards, and motor control centers shall be 6 ft 6 in.
+### Every entrance shall pass the largest shipping section of the equipment in the room with its packaging removed, and the Contractor shall verify the clear opening of every door against the reviewed shipping dimensions before the frame is ordered.
−## Where the electrical equipment exceeds 6 ft 6 in. in height, the minimum headroom shall not be less than the height of the equipment.
+### Where a section of the largest equipment in the room cannot pass through the smallest door of the room, the Contractor shall report the conflict to the Engineer of Record before the frame is ordered, and shall not resolve it by removing a wall after the equipment is set.
−## Lighting fixtures, sprinkler piping, HVAC ductwork, and structural members all count against headroom when they intrude into the volume above equipment.
+### The door that lets the equipment in is the door that lets its replacement out, and a room built around a switchgear section that entered through a wall opening before the wall was closed has committed the Owner to opening that wall again. A pair of doors with a removable mullion is the common answer where a single leaf cannot pass the section. {note}
−## A 12 ft clear room height is a practical default for rooms with low-voltage switchgear (typically 90 in. to 96 in. tall) because it accommodates the 6 ft of dedicated equipment space above the switchgear with margin for conduit, lighting, and HVAC. {note}
+## Door Swing and Hardware {toc}
−## Rooms with medium-voltage switchgear or with very tall lineups require greater clear height.
+### Where the room contains equipment rated 800 A or more, every personnel door within 25 ft of the nearest edge of the working space shall open in the direction of egress and shall be equipped with listed panic hardware or listed fire exit hardware, in accordance with NFPA 70 110.26(C)(3).
−## Coordinate with the equipment manufacturer's shop drawings before finalizing the room dimensions.
+### Where the room contains equipment rated over 1000 V, every personnel door shall open in the direction of egress and shall be equipped with listed panic hardware or listed fire exit hardware, in accordance with NFPA 70 110.33(A)(3).
−# Dedicated Equipment Space {toc}
+### The panic hardware policy for electrical room doors not covered by the two preceding clauses shall be as indicated in the datasheet.
−## The dedicated electrical space is one of the most commonly violated provisions in field conditions; the space above each line-up is reserved for electrical use only. {note}
−
−## The extent of the dedicated equipment space is fixed by NEC 110.26(E) — the width and depth of the equipment, from the floor to 6 ft above the equipment or to the structural ceiling if lower — so it is not a datasheet selection. {note}
−
−## The ceiling treatment above the dedicated equipment space envelope shall be as indicated in the datasheet.
−
```datasheet
−label: Ceiling Above Dedicated Equipment Space
+label: Panic Hardware Policy
type: radio
options:
− - "None — room open to structure"
− - "Dropped ceiling above the dedicated space envelope"
+ - "Listed panic hardware or fire exit hardware on every electrical room door"
+ - "Panic hardware only where NFPA 70 110.26(C)(3) or 110.33(A)(3) requires it"
```
−## Per NEC 110.26(E), the space equal to the width and depth of the equipment and extending from the floor to a height of 6 ft above the equipment, or to the structural ceiling if lower, shall be reserved for electrical installations exclusively.
+### Panic hardware on every electrical room door gives every room the same exit, costs a panic device and an outswinging leaf per door, and removes the question of which rooms crossed the 800 A threshold when a lineup was enlarged; hardware only where the code requires it costs less on a building with many small closets and leaves a closet door that swings into the corridor to the Owner's keying and the lever on the inside. Both are code-compliant; the difference is what a facility wants every one of its electrical doors to do. {note}
−## No piping, ductwork, or other equipment foreign to the electrical installation shall be installed in or pass through the dedicated electrical space.
+### Every electrical room door shall be openable from inside the room without a key, a tool or special knowledge, and no locking device shall prevent egress from the room.
−## Sprinklers, fire-suppression piping, and similar systems serving the room itself are permitted in the dedicated space provided they do not interfere with equipment access.
+### A door in a rated wall shall be a listed fire door assembly of the rating [[sync/fire-rated-wall-and-floor-assemblies]] requires for the opening, installed under NFPA 80, and its panic hardware shall be fire exit hardware listed for that assembly.
−## The 6 ft above each piece of switchgear, switchboard, panelboard, and motor control center is not free volume that mechanical or plumbing trades may use for their distribution mains. {note}
+### The locking provision of each electrical room door shall be as indicated in the datasheet.
−## Where the structural ceiling is lower than 6 ft above the equipment, the entire vertical run from the equipment to the structural ceiling is dedicated and protected.
−
−## Where the room ceiling exceeds 6 ft above the equipment and a finished or dropped ceiling is present, the volume above the dropped ceiling outside the dedicated space envelope may be used for non-electrical systems, provided a suitable barrier (such as the ceiling itself) is installed to prevent any leak or condensation from foreign systems from impinging on electrical equipment.
−
−## NEC 110.26(F) further restricts piping and ductwork that may pass through electrical rooms; see Drainage and Plumbing Restrictions, below. {note}
−
−# Door and Egress {toc}
−
−## The door swing direction shall be as indicated in the datasheet.
−
```datasheet
−label: Door Swing Direction
+label: Door Locking
type: radio
options:
− - "Out of room, in the direction of egress"
− - "Into room"
−default: "Out of room, in the direction of egress"
+ - "Keyed lockset on the Owner's keying system"
+ - "Electronic access control"
+default: "Keyed lockset on the Owner's keying system"
```
−## The latching and egress hardware shall be as indicated in the datasheet.
+### A keyed lockset costs a cylinder and a key record and is what most buildings fit on a room that qualified persons enter a few times a year; electronic access control costs a reader, a controller, a strike or electrified device and cabling, and buys a record of who entered and when, the ability to revoke a credential without rekeying, and a door position signal the facility can alarm on. The electronic provision earns its cost where the Owner's security program already covers the building or where the room holds the service, the emergency system or equipment over 1000 V. {note}
−```datasheet
−label: Door Egress Hardware
−type: radio
−options:
− - "Listed panic hardware (free egress from inside without tools)"
− - "Listed fire-exit hardware (rated door assembly)"
− - "Standard latch with inside lever"
−```
+### Where electronic access control is selected, the door shall be placed on the building's access control system under [[sync/access-control-systems]], the locking device shall fail to a state that permits free egress, and a mechanical key override shall be provided for entry on loss of the system.
−## Doors to electrical rooms shall open in the direction of egress per NEC 110.26(C)(3) where the room contains equipment rated 800 A or more.
+### The doors, frames, panic hardware, closers and locksets shall be furnished and installed under [[sync/doors-frames-and-hardware]] or [[sync/door-hardware]] as the project's door package is organized, to the swing, clear opening, rating and hardware this standard requires.
−## Door swing shall be coordinated with the egress path of any room occupant under fault conditions.
+### A mantrap, a turnstile or a delayed-egress device shall not be installed on an electrical room door unless the Owner requires it in writing and the Authority Having Jurisdiction accepts it.
−## Where the room contains equipment rated 800 A or more, doors shall be equipped with panic hardware or other listed fire-exit hardware that opens under simple pressure from inside the room without keys, tools, or special knowledge, per NEC 110.26(C)(3).
+## Egress Path {toc}
−## Where the door is part of a fire-rated assembly, the egress hardware shall be listed fire-exit hardware for that assembly.
+### A continuous and unobstructed path not less than the width of the working space shall be maintained from every point of the working space to each entrance, and no equipment, pad, pipe or stored item shall narrow it.
−## Standard latching hardware shall be used only where the room contains no equipment rated 800 A or more and the door is not part of a fire-rated assembly.
+### The egress path from the working space shall be shown on the coordination drawing and shall not pass through the working space of another lineup where a second entrance or the doubled working space depth is relied on to satisfy NFPA 70 110.26(C)(2).
−## The room shall be capable of being secured against unauthorized entry from outside while preserving free egress from inside; locking devices that prevent egress are prohibited.
+# Enclosing Construction {toc}
−## Where the room is publicly accessed for any reason, ICC A117.1 accessibility requirements apply to the path of travel, the door operating effort, and the threshold.
+## Fire-Resistance Rating {toc}
−## The working space inside the room is exempt from accessibility maneuvering clearance requirements because operating personnel are qualified persons under NEC and not public users. {note}
+### The fire-resistance rating of the walls, floor and ceiling enclosing each electrical room shall be as indicated in the datasheet.
−## Number of Entrances and Doors {toc}
−
−### The number of entrances serving the working space shall be as indicated in the datasheet.
−
```datasheet
−label: Number of Entrances to Working Space
−type: radio
−drawing_ref: "electrical room layout drawings"
+label: Enclosing Construction Fire-Resistance Rating
+type: range
+unit: hours
+drawing_ref: "the code analysis drawing"
options:
− - "Single entrance"
− - "Two entrances, one at each end of the working space"
+ min: 0
+ max: 3
+ setpoints: [0, 1, 2, 3]
default: deferred
+constraint: min
```
−### The door clear opening shall be as indicated in the datasheet.
+### No code rates an electrical room as such; the rating is set by what the room holds. NFPA 70 450.21(B) puts a dry-type transformer rated above 112.5 kVA in a room of fire-resistant construction unless its insulation system and enclosure meet the exception that section provides, and fire-resistant construction is one hour as [[parameter: adopted-building-code]] defines it. NFPA 110 Chapter 7 puts a Level 1 generator set installed indoors in a room separated by two-hour construction. [[parameter: adopted-building-code]] separates a stationary battery room and a fire pump room as incidental uses, and separates the room from an adjacent occupancy of a different group. An Owner's insurer sometimes asks for more than any of them, and a room that holds nothing on those lists carries no rating at all. The code analysis is where those drivers are reconciled room by room, which is why the value is read from it. {note}
−```datasheet
−label: Door Clear Opening (Minimum)
−type: range
−unit: in
−drawing_ref: "door and hardware schedule"
−options:
− min: 32
− max: 48
− setpoints: [32, 36, 42, 48]
−default: deferred
−```
+### The rated assemblies enclosing the room shall be built to the design numbers [[sync/fire-rated-wall-and-floor-assemblies]] documents for them, under [[sync/gypsum-board-assemblies]] or [[sync/unit-masonry]] as the assembly is constructed, and shall extend from the floor to the underside of the floor or roof above.
−### Per NEC 110.26(C)(2), for equipment rated 1200 A or more and over 6 ft wide that contains overcurrent devices, switching devices, or control devices, the room shall have one entrance not less than 24 in. wide and 6 ft 6 in. high at each end of the working space.
+### Every raceway, busway, cable tray, pipe, duct and louver that penetrates a rated wall, floor or ceiling of the room shall be firestopped under [[sync/firestopping]], and every duct or louver opening in a rated wall shall carry the fire damper or combination fire and smoke damper [[sync/louvers-and-dampers]] requires for that assembly.
−### A single entrance is permitted where the location permits a continuous and unobstructed way of egress travel, or where the working space depth is twice that required by NEC 110.26(A)(1) so that personnel can move away from the equipment in either direction.
+### The extent of the rated enclosure of each room and the rating of each assembly shall be as indicated on [[drawing: the code analysis drawing]].
−### Equipment shipping splits, replacement section sizes, and racking devices for drawout breakers shall be verified against the door opening before construction so that future replacement is not constrained by the room itself.
+## Walls, Ceiling and Finishes {toc}
−### Where any section of the largest installed equipment cannot pass through the smallest door of the room, the door schedule shall be revised.
+### The walls and the ceiling of the room shall have a hard, sealed surface that does not shed dust or fibers, and where the parties disagree whether a surface sheds, the Engineer of Record shall make the determination.
−# Fire Resistance Ratings {toc}
+### Exposed insulation, unsealed concrete masonry and unpainted gypsum board are each a surface that sheds into the ventilation openings of the equipment below them, and a room whose walls are painted and whose ceiling is sealed is one in which the equipment interior stays clean between maintenance cycles. {note}
−## The enclosing assemblies of an electrical room — walls, floor, and ceiling — are rated based on the occupancy classification of the building and the role of the room, and are governed by the International Building Code. {note}
−## Electrical rooms are commonly classified as utility (Section 304) or as accessory to the principal occupancy. {note}
+### A suspended acoustical ceiling shall not be installed over the dedicated electrical space of any lineup, and where one is installed elsewhere in the room it shall not reduce the clear height this standard requires.
−## The fire-resistance rating of the assemblies enclosing the room shall be as indicated in the datasheet.
+### Interior wall and ceiling surfaces shall be painted under [[sync/interior-painting]] before the equipment is set, and no painting shall be performed over installed equipment.
−```datasheet
−label: Enclosing Assembly Fire-Resistance Rating
−type: select
−unit: hour
−drawing_ref: "code and life-safety plan"
−options:
− - "Not rated"
− - "1 hour"
− - "2 hour"
− - "3 hour"
−default: deferred
−```
+# Foreign Systems and Water Protection {toc}
−## The basis on which the required rating is demonstrated shall be as indicated in the datasheet.
+## Piping and Ductwork Elsewhere in the Room {toc}
+### The provision for piping and ductwork foreign to the electrical installation outside the dedicated electrical space shall be as indicated in the datasheet.
+
```datasheet
−label: Fire-Resistance Test Basis
+label: Foreign Piping and Ductwork Outside the Dedicated Electrical Space
type: radio
options:
− - "ASTM E119 / UL 263 listed wall and floor/ceiling assembly"
− - "Per IBC prescriptive table"
−default: "ASTM E119 / UL 263 listed wall and floor/ceiling assembly"
+ - "Not permitted anywhere in the room"
+ - "Permitted outside the dedicated electrical space and the working space, with protection against leaks and condensation"
```
−## The Electrical Engineer shall coordinate with the Architect of Record to confirm the required fire-resistance ratings.
+### The code excludes foreign systems from the dedicated electrical space and permits them elsewhere in the room with protection. A room that admits none of them costs other trades a longer route around the room and buys a room in which no pipe can ever drip on a lineup and no duct can ever be hung in a working space; a room that admits them outside the clearances costs drip shields, leak protection and a coordination drawing that every trade honors, and buys the shorter routing that a crowded floor plate often needs. On a floor where the electrical room sits in the core beside the mechanical shaft, the second provision is frequently the only one the plan allows. {note}
−## Where the room serves multiple tenants or stories, separation requirements increase. {note}
+### Where foreign piping is permitted in the room, no pipe carrying water, steam, refrigerant, fuel or drainage shall be routed above any electrical equipment or above its working space, and every such pipe elsewhere in the room shall be provided with the drip shield this standard requires for foreign systems above the dedicated space.
−## Where the room contains equipment rated for the entire building service, additional separation is often required by the building code or by insurer requirements. {note}
+### Where foreign ductwork is permitted in the room, it shall be routed outside the dedicated electrical space and the working space, and any duct that serves a space other than the room shall carry no access door, damper or coil that is serviced from inside the room.
−## A 2-hour rating is a defensible default for rooms containing service entrance equipment, equipment serving multiple tenants, or equipment with main devices rated 1200 A or more in multi-story buildings; a 1-hour rating is common for distribution closets serving a single tenant or floor. {note}
+### Water-based fire suppression piping serving the room shall not pass through the dedicated electrical space of any lineup, and the sprinkler protection of the room shall be arranged under [[sync/wet-pipe-fire-sprinkler-systems]] or [[sync/pre-action-and-deluge-sprinkler-systems]] so that its piping complies with NFPA 70 110.26(E)(1).
−## The Architect of Record shall confirm the required rating by reference to the building code occupancy and construction type.
+### NFPA 13 permits sprinklers to be omitted from an electrical equipment room that is dedicated to dry-type electrical equipment, enclosed in two-hour construction and used for no storage, and the fire protection standards decide for each project whether the room is sprinklered, pre-action protected, clean agent protected or left to that omission. This standard decides only where the piping cannot go. {note}
−## The wall, floor, and ceiling assemblies shall be constructed under [[sync/gypsum-board-assemblies]] or the applicable structural and architectural scopes.
+### A roof drain leader, a domestic water riser, a sanitary stack or a storm drain shall not be routed through an electrical room under either provision of the datasheet.
−## Penetrations of the rated assemblies for raceway, cable tray, ductwork, sprinkler piping, and any other service shall be sealed with listed firestop systems per [[sync/firestopping]].
+## Water Entry at the Door {toc}
−## The extent of the fire-rating boundary enclosing each room shall be shown with hatching and a legend identifying each rating [[drawing: on the code and life-safety plan]].
+### The water barrier at the door of each room shall be as indicated in the datasheet.
−# Ventilation and Cooling {toc}
−
−## Electrical equipment converts a small fraction of its throughput to heat under normal operation, and a larger fraction during fault conditions or after motor starts. {note}
−
−## The means of rejecting equipment heat from the room shall be as indicated in the datasheet.
−
```datasheet
−label: Heat Rejection Strategy
+label: Door Threshold Curb
type: radio
options:
− - "Exhaust ventilation (gravity or fan-driven) with outside air supply"
− - "Mechanical cooling (dedicated CRAC or split system)"
− - "Connection to building HVAC system"
− - "Hybrid — ventilation primary, mechanical cooling supplemental"
−default: "Mechanical cooling (dedicated CRAC or split system)"
+ - "None"
+ - "Raised curb or threshold at every door"
+default: "None"
```
−## Where ventilation air is supplied to the room, its source and its discharge routing shall be as indicated in the datasheet.
+### A curb or a raised threshold holds a sprinkler discharge, a cleaning cart spill or a flooded corridor out of the room, at the cost of a step at every door that a lift truck, a breaker cart and a pallet jack have to ramp over. It earns its cost where the room is below grade, where it sits beside a wet room or a loading dock, or where the corridor outside it is washed down; on an upper floor beside dry offices it is a tripping hazard that protects against nothing. {note}
−```datasheet
−label: Ventilation Air Source
−type: radio
−options:
− - "Outdoor air directly (louver to exterior)"
− - "Outdoor air via ductwork from a clean intake"
− - "Building return / recirculated air"
−```
+### Where a curb or raised threshold is selected, it shall be not less than 2 in. above the adjacent floor, shall be continuous across the opening, and shall be provided with a ramp or a removable plate on the room side so that equipment can be rolled across it.
+## Floor Drainage {toc}
+
+### The floor drain provision of each room shall be as indicated in the datasheet.
+
```datasheet
−label: Discharge Air Routing
+label: Floor Drain
type: radio
options:
− - "Direct to exterior louver"
− - "Ducted to exterior, with fire damper at rated wall penetration"
− - "Into building return, with documented heat capture in the building system"
+ - "Not provided"
+ - "Provided at a low point of the floor, clear of the working space and the dedicated electrical space"
+default: "Not provided"
```
−## The air source and discharge routing follow from the heat rejection strategy and from where the room sits in the building, so neither carries a default. {note}
+### A floor drain removes the water that a sprinkler discharge, a leaking pipe or a flooded corridor puts on the floor before it reaches the base of a lineup, and it costs a trap that dries out and vents sewer gas into a room that is rarely entered, a trap primer to keep it wet, and a sloped floor under equipment that wants to be level. A room with no water source in it and nothing wet beside it has nothing for a drain to remove, which is why most electrical rooms have none; a room that is sprinklered, that holds a vented battery or that lies below grade has a reason for one. {note}
−## The room shall reject equipment heat continuously so that the equipment ambient does not exceed its nameplate rating.
+### Where a floor drain is selected, it shall be furnished under [[sync/sanitary-drainage-specialties]] with a trap primer, the floor shall slope to it at not less than 1/8 in. per foot from the pad edges, and the drain shall be located outside the working space and the dedicated electrical space of every lineup.
−## Heat-rejection calculations shall be performed for every electrical room and shall be based on the equipment nameplate losses, the connected load profile, and the worst-case simultaneity factor for the installed equipment.
+### Where a floor drain is selected in a room that holds a vented battery, the drain shall discharge through the neutralization provision [[sync/dc-battery-systems]] requires and not directly to the sanitary system.
−## Mechanical cooling is the default for rooms housing service entrance equipment, switchgear, motor control centers, and transformers in temperate and warm climates because it provides reliable temperature and humidity control independent of outdoor conditions. {note}
+# Room Environment {toc}
−## Exhaust ventilation is appropriate for small distribution closets in mild climates and for rooms whose connected load profile keeps heat rejection low. {note}
+## Heat-Release Basis {toc}
−## Connection to the building HVAC system is appropriate only where the room's continuous cooling demand is small relative to the building system and where the building system runs continuously, because the building system is typically scheduled off during unoccupied hours when electrical loads continue. {note}
+### The basis on which the heat released into each room is computed shall be as indicated in the datasheet.
−## Ventilation intake and discharge openings shall be located so that the air path crosses the equipment line-up and so that hot discharge air is not re-entrained.
−
−## Where the room is on the building exterior, intake and discharge louvers shall be weatherproof, bird-screened, and protected against snow loading and wind-driven rain.
−
−## Where intake or discharge passes through a rated wall, listed fire dampers shall be provided per [[sync/firestopping]] and the mechanical scope.
−
−## Where the room contains a battery system, hydrogen evolution shall be addressed per [[sync/dc-battery-systems]] and IEEE 484 or IEEE 1187, with ventilation rates sized to limit hydrogen accumulation below 1 percent of room volume.
−
−# Illumination {toc}
−
−## Illumination of working spaces about indoor electrical equipment is required by NEC 110.26(D) and shall be manually controllable, of adequate level, and backed by emergency lighting.
−
−## The lighting control arrangement shall be as indicated in the datasheet.
−
```datasheet
−label: Lighting Control
+label: Heat-Release Basis
type: radio
options:
− - "Manual switch at door, occupancy sensor permitted as a supplement"
− - "Three-way switching at each entrance"
− - "Manual-on vacancy sensor with manual override"
−default: "Manual switch at door, occupancy sensor permitted as a supplement"
+ - "Full-load losses of every item of equipment in the room"
+ - "Losses at the calculated design load of each item of equipment"
+default: "Full-load losses of every item of equipment in the room"
```
−## The maintained illuminance at the working plane shall be as indicated in the datasheet.
+### Full-load losses are the values the equipment standards require each manufacturer to state, so they are available from the reviewed shop drawings without a load study, and they give a room that holds its limit on the day every feeder is loaded to its rating; the sum overstates the room's heat on every other day, which oversizes the ventilation or cooling by the ratio of design load to rating. Design-load losses give a smaller fan or cooling unit, at the cost of a load calculation that has to be redone when the building's load grows, and of a room that runs hot the year that growth arrives. {note}
−```datasheet
−label: Maintained Illuminance at Working Plane
−type: range
−unit: fc
−options:
− min: 30
− max: 100
− setpoints: [30, 50, 75, 100]
−default: 50
−```
+### The Contractor shall compile the room heat-release schedule from the reviewed shop drawings of every item of equipment in the room, at the basis selected in the datasheet, and shall issue it to the trade responsible for the room's ventilation or cooling before that design is fixed.
−## The emergency lighting source serving the room shall be as indicated in the datasheet.
+### The heat-release schedule shall include the losses of every transformer, drive, UPS module, battery charger, switchgear and switchboard section, motor control center section, panelboard, busway run and generator set in the room, and the heat released by any open generator set shall be the value the generator standard states for the set with its radiator discharge ducted out of the room.
+## Heat Rejection Method {toc}
+
+### The method by which each room rejects the heat released into it shall be as indicated in the datasheet.
+
```datasheet
−label: Emergency Lighting
+label: Heat Rejection Method
type: radio
options:
− - "Battery-backed luminaire (90-minute minimum per NFPA 101)"
− - "Connection to building emergency branch"
− - "Both — separate sources for redundancy"
−default: "Battery-backed luminaire (90-minute minimum per NFPA 101)"
+ - "Ventilation with outdoor air or building air"
+ - "Mechanical cooling"
+ - "Ventilation with mechanical cooling for the hours ventilation cannot hold the limit"
```
−## Per NEC 110.26(D), illumination shall be provided for all working spaces about service equipment, switchboards, panelboards, and motor control centers installed indoors.
+### Ventilation moves the room's heat out on a stream of outdoor or building air and costs a fan, a louver or a transfer opening and a damper at the rated wall; it holds the room to the outdoor temperature plus the rise the airflow allows, so it holds a 40°C limit where [[parameter: site-ambient-temperature-maximum]] leaves margin below it and cannot hold a lower limit on a hot day at all, and it brings in whatever the outdoor air carries. Mechanical cooling costs a cooling unit, a refrigerant or chilled-water connection and a condensate drain, and holds any limit in any weather with filtered, dehumidified air, which is what electronics, drives and batteries ask for; it also makes the room's temperature depend on a machine that can fail. Ventilation backed by cooling costs both and runs the fan for most of the year with the cooling unit for the hottest hours, which is the lowest energy of the three where the limit is low and the climate is mild. The method follows from the limit the equipment imposes, from the site climate and from the hours the room's load runs, so none of the three is the norm. {note}
−## The illumination shall not be controlled by automatic means only — manual control shall be provided so that personnel entering the room can confirm the lights are on.
+### The ventilation or cooling of the room shall hold the room air temperature within the limits of the datasheet with every item of equipment releasing heat at the heat-release basis and with the outdoor air at [[parameter: site-ambient-temperature-maximum]].
−## The intent is that a worker entering the room cannot be left in the dark by an occupancy-sensor timeout or by a building-management schedule. {note}
+### The fans, louvers, dampers, ductwork and cooling units that condition the room shall be furnished and installed under [[sync/hvac-fans]], [[sync/louvers-and-dampers]], [[sync/hvac-ductwork]], [[sync/split-system-air-conditioners]], [[sync/fan-coil-units]] or [[sync/computer-room-air-conditioning]] as the mechanical design selects them, and this standard governs only the conditions the room has to hold.
−## A maintained 50 footcandle level on a vertical reference at the equipment face is the typical default and supports nameplate reading, breaker handle identification, and visual inspection. {note}
+### Where ventilation is selected, the intake and the discharge shall be placed so that the air path crosses the equipment that releases the heat, so that the discharge is not drawn back into the intake, and so that the intake does not draw from a loading dock, a parking structure, a kitchen exhaust, a generator exhaust or a cooling tower plume.
−## Higher levels (75 to 100 footcandles) shall be provided where infrared scanning windows are routinely used or where the equipment line-up is densely labeled.
+### Where ventilation is selected and the intake is exposed to dust, salt, corrosive vapor or vehicle exhaust, the intake air shall be filtered, and where the parties disagree whether the exposure exists, the Engineer of Record shall make the determination.
−## Lower illumination levels are not acceptable in rooms with switchgear or motor control centers.
+### Where mechanical cooling is selected, the cooling unit shall be located outside the dedicated electrical space and the working space, its condensate shall be drained to a point outside the room or to the floor drain where one is selected, and no refrigerant or chilled-water piping shall pass above any electrical equipment.
−## The lighting power density of the room shall comply with ASHRAE 90.1 or the adopted IECC, whichever is more stringent.
+### A cooling unit hung above a switchboard is a water source above live parts, and a condensate line routed to the nearest drain through the dedicated space is a pipe where the code forbids one. The unit belongs on a wall or a floor stand outside both clearances, with its piping routed the long way. {note}
−## Emergency lighting shall be provided per NFPA 101 to maintain the means of egress under loss of normal power.
+### Where the room holds the equipment of an emergency or legally required standby system, the cooling or ventilation of the room shall be supplied from the same system so that the room holds its limits while the normal source is lost.
−## Where the room itself houses the building's emergency or standby source, the emergency lighting shall be supplied from a separate source from the equipment under maintenance (typically a battery-backed luminaire).
+## Temperature Limits {toc}
−## Lighting fixtures shall not be installed within the dedicated equipment space envelope.
+### The upper limit of the room air temperature shall be as indicated in the datasheet.
−# Power and Receptacles {toc}
−
−## Convenience receptacles and the room lighting circuit shall be powered from a source independent of the equipment under maintenance, so that de-energizing that equipment does not disable the tools and lights needed to service it.
−
−## The extent of convenience receptacle coverage in the room shall be as indicated in the datasheet.
−
```datasheet
−label: Convenience Receptacles
−type: select
+label: Room Air Temperature Upper Limit
+type: range
+unit: °C
+derived: "the lowest rated ambient temperature among the equipment in the room, taken from the reviewed shop drawings"
options:
− - "One GFCI 125 V receptacle within 25 ft of each equipment line-up (NEC 210.63 minimum)"
− - "GFCI receptacles at each end of the working space"
− - "Receptacles along each wall at 12 ft maximum spacing"
−default: "GFCI receptacles at each end of the working space"
+ min: 25
+ max: 50
+ setpoints: [25, 30, 35, 40, 45, 50]
+default: derived
+constraint: max
```
−## The source of the room lighting circuit shall be as indicated in the datasheet.
+### Switchgear, switchboards, panelboards, motor control centers and dry-type transformers carry their nameplate ratings at a 40°C ambient, so a room of such equipment holds 40°C with no derating; a drive, a UPS module, a battery charger and most electronic protective relays are rated at 40°C as well but age faster above 25°C to 30°C, and a lead-acid battery loses half its service life for every 8°C to 10°C above 25°C, which is why a room that holds those is held lower. The limit is the lowest rated ambient in the room, and the engineer overrides it downward where the service life of the electronics or the battery is worth the cooling. {note}
+### The lower limit of the room air temperature shall be as indicated in the datasheet.
+
```datasheet
−label: Lighting Circuit
−type: radio
+label: Room Air Temperature Lower Limit
+type: range
+unit: °C
options:
− - "Dedicated circuit fed from a panel outside the room"
− - "Dedicated circuit fed from a panel within the room that is not the equipment under maintenance"
−default: "Dedicated circuit fed from a panel outside the room"
+ min: -10
+ max: 20
+ setpoints: [-10, -5, 0, 5, 10, 15, 20]
+constraint: min
```
−## The room lighting shall be served by a dedicated circuit fed from a panel outside the room unless otherwise indicated in the datasheet.
+### Switchgear and switchboards are rated for a minimum ambient of -5°C to -30°C depending on the standard they are built to, a drive and a UPS module for 0°C, and a lead-acid battery loses capacity below 20°C and is sized for the lowest temperature it sees, so the lower limit follows from the most cold-sensitive item in the room. An interior room on an occupied floor never approaches any of these limits and needs no heat; a room on an exterior wall of an unheated structure, a room beside a loading dock door or a room that ventilates with outdoor air through the winter needs a heater to hold the limit at [[parameter: site-ambient-temperature-minimum]], and the limit then decides how large that heater is. {note}
−## Per NEC 210.63, a 125 V, single-phase, 15 A or 20 A receptacle outlet shall be installed in an accessible location within 25 ft of each piece of service equipment, switchboard, panelboard, or motor control center.
+### Where the losses of the equipment and the heat of the surrounding building cannot hold the lower limit with the outdoor air at [[parameter: site-ambient-temperature-minimum]], the room shall be heated by a unit heater furnished under [[sync/unit-heaters]], located outside the dedicated electrical space and the working space, and where ventilation is selected the ventilation shall be dampered or staged so that it does not drive the room below the limit.
−## The receptacle shall not be connected to the load side of the equipment it serves, so that if the equipment is de-energized for maintenance the receptacle remains energized for test instruments, work lights, and tools.
+### Where the room holds a control-power battery or an energy storage system, the room shall hold the temperature range [[sync/dc-battery-systems]] or [[sync/battery-energy-storage-systems]] requires for the battery, which shall govern over the limits of the datasheet where it is narrower.
−## The receptacle shall be fed from a panel in an adjacent area or from a dedicated panel that is not part of the maintained equipment.
+## Humidity {toc}
−## Receptacles in electrical rooms shall be GFCI-protected per NEC 210.8 where required by the room's classification (unfinished spaces, similar conditions).
+### The room shall be held non-condensing, and the surface temperature of every enclosure in the room shall remain above the dew point of the room air at every operating condition.
−## Receptacles shall not be installed inside the dedicated equipment space envelope of NEC 110.26(E).
+### The upper limit of the room relative humidity shall be as indicated in the datasheet.
−## The lighting and receptacle circuits shall not be fed from the equipment under maintenance in the room.
+```datasheet
+label: Room Relative Humidity Upper Limit
+type: range
+unit: '% RH'
+options:
+ min: 50
+ max: 95
+ setpoints: [50, 60, 70, 80, 90, 95]
+constraint: max
+```
−## Powering the room's own lights and receptacles from the main panel housed in the room is a common error, because taking the main panel out of service then plunges the room into darkness and disables the receptacles needed for tools. {note}
+### A ventilated room follows the outdoor humidity and the only limit it can hold is the non-condensing condition, so a ventilated room's limit is written at the high end to record what the equipment tolerates rather than what the room controls; a mechanically cooled room dehumidifies as it cools and holds a limit of 50 to 60 percent without a separate provision, which is where electronics, drives and the insulation of medium-voltage equipment are kept dry. A cold-weather room with an outdoor-air intake can reach saturation on a mild wet day after a cold night, which is the condition under which an enclosure sweats and a bus flashes over, and it is the reason a ventilated room in a humid climate is given space heaters in the equipment under the equipment standards rather than a humidity limit here. {note}
−# Drainage and Plumbing Restrictions {toc}
+### Where the datasheet selects mechanical cooling, the cooling unit shall hold the relative humidity limit of the datasheet at the room's design heat release.
−## Foreign piping is excluded from the dedicated equipment space, and any drainage provided shall be located clear of equipment and the working space.
+## Battery Rooms {toc}
−## The treatment of foreign piping within the room shall be as indicated in the datasheet.
+### A room that houses a vented battery shall provide the ventilation openings, the exhaust path, the hydrogen detector location, the eyewash and safety shower and the floor containment that [[sync/dc-battery-systems]] or [[sync/battery-energy-storage-systems]] requires for the battery, and those requirements shall be shown on the coordination drawing.
−```datasheet
−label: Foreign Piping in Room
−type: radio
−options:
− - "Not permitted — no piping through the room"
− - "Permitted outside the dedicated space, with drip pans and leak detection above equipment"
− - "Permitted outside the dedicated space, with no piping over equipment"
−default: "Permitted outside the dedicated space, with no piping over equipment"
−```
+### The ventilation of a battery room shall exhaust from the highest point of the room, shall not recirculate to another electrical room, and shall not pass through the ventilation or cooling of a room that holds other electrical equipment.
−## The floor drainage provided in the room shall be as indicated in the datasheet.
+### Where a battery is installed in a cabinet inside an electrical room rather than in its own room, the room ventilation or cooling shall account for the cabinet's hydrogen venting and heat release as the battery standard states them.
+## Room Condition Monitoring {toc}
+
+### The room conditions reported to the building automation system shall be as indicated in the datasheet.
+
```datasheet
−label: Floor Drainage
−type: radio
+label: Room Conditions Reported to the Building Automation System
+type: checkbox
options:
− - "No floor drain"
− - "Floor drain at the low point, located clear of equipment"
− - "Floor drain with trap primer, located clear of equipment"
+ - "High room air temperature"
+ - "Loss of ventilation or cooling"
+ - "Water on the floor"
+ - "Door open"
+constraint: all_of
```
−## Whether a floor drain is required is set by the room's plumbing exposure, sprinkler protection, and battery content, which are per-project conditions, so the field carries no default. {note}
+### Each selected condition shall be reported to the building automation system under [[sync/building-automation-system]] as an alarm, with the high temperature alarm set 5°C below the upper limit of the datasheet, the water alarm from a leak detection cable or spot sensor on the floor at the low point of the room, and the door alarm from the door position switch of the access control system where electronic access control is selected.
−## Per NEC 110.26(F), piping and ductwork foreign to the electrical installation shall not be located in the dedicated equipment space envelope.
+### Where the room holds a UPS, the points the UPS reports to the building automation system under [[sync/uninterruptible-power-supply-systems]] shall be carried on the same network as the room's own alarms, and the room's high temperature alarm shall be set below the UPS's own ambient alarm so that the room alarms first.
−## Beyond the dedicated space envelope, plumbing and HVAC systems may pass through the electrical room but shall be arranged so that any leak, condensation, or rupture cannot impinge on electrical equipment.
+### An electrical room is entered a few times a year, so the cooling unit that fails in June is found when the switchgear trips on an overtemperature in August unless the room reports the condition the day it occurs. The four points cost a sensor, a cable and a point on a controller each, and a room that holds the service, the emergency system, a UPS or a battery is one in which that cost is small against the day they buy. A closet of panelboards on an occupied floor rarely needs any of them. {note}
−## Where any piping passes through the room, it shall be located so that no portion of the piping is above any equipment.
+# Illumination and Convenience Power {toc}
−## Where piping above equipment is unavoidable, listed drip pans with leak alarms shall be installed below the piping and above the equipment, and the leak alarm shall be wired into the building management system.
+## Working Space Illumination {toc}
−## Sprinkler piping serving the electrical room itself is permitted in the dedicated space provided it does not interfere with equipment access.
+### Illumination shall be provided for the working space about every lineup in the room, in accordance with NFPA 70 110.26(D) for equipment rated 1000 V and below and NFPA 70 110.34(D) for equipment rated over 1000 V.
−## The discharge of water onto energized equipment shall be addressed by the fire-protection scope through pre-action systems or equivalent measures where the project warrants.
+### The maintained illuminance at the working plane of each working space shall be as indicated in the datasheet.
−## A floor drain shall be provided in any electrical room with plumbing exposure, with sprinkler protection, or with a battery system, located at the low point of a sloped floor and clear of any equipment line-up.
+```datasheet
+label: Working Space Illuminance
+type: range
+unit: fc
+options:
+ min: 10
+ max: 100
+ setpoints: [10, 20, 30, 50, 75, 100]
+default: 30
+constraint: min
+```
−## The floor drain shall be sized and routed so that it does not introduce sewer gas or vermin into the electrical room.
+### The code requires illumination and sets no level. Thirty footcandles, measured vertically at the equipment face at the height of the device handles, is the level most illumination references recommend for an electrical equipment room and is enough to read a nameplate, identify a breaker and see a connection; 50 fc and above are chosen where infrared inspection windows are read, where a lineup is densely labeled or where relay settings are entered from a front panel; 10 to 20 fc is a closet of panelboards whose directories are read at arm's length. The level is measured in the working space and not at the center of the room, because the luminaires sit outside the dedicated space and the vertical face of the equipment is what the worker reads. {note}
−## Drains shall not be located within the working space or the dedicated equipment space.
+### Every luminaire in the room shall be located outside the dedicated electrical space of every lineup, and shall be located so that a person relamping or servicing it is not exposed to live parts and does not stand in front of an open compartment to reach it.
−# Grounding and Bonding {toc}
+### The luminaires shall be furnished under [[sync/lighting-fixtures]] and the lighting power of the room shall comply with [[parameter: adopted-energy-code]].
−## A dedicated equipment ground bus provides a single termination point for the equipment grounding conductors of each line-up, for the grounding conductors of raceway systems entering and leaving the room, and for the bonding of metallic structural elements within the room. {note}
+### The control of the working space illumination shall be as indicated in the datasheet.
−## The room ground bus construction shall be as indicated in the datasheet.
−
```datasheet
−label: Room Ground Bus
+label: Working Space Lighting Control
type: radio
options:
− - "Tin-plated copper bar, full length of equipment line-up"
− - "Bare copper bar, full length of equipment line-up"
− - "Multiple distributed ground bars bonded together"
+ - "Manual switches at each entrance, with no automatic control"
+ - "Manual switches at each entrance, with an occupancy sensor that turns the lighting off"
+ - "Manual switches at each entrance, with an occupancy sensor that turns the lighting on and off"
```
−## A dedicated equipment ground bus shall be provided in each electrical room and shall be bonded to the building grounding electrode system per [[sync/grounding-and-bonding]].
+### NFPA 70 110.26(D) forbids control of the working space illumination by automatic means alone, so every provision begins with a manual switch at each entrance. Manual switches alone cost the least and leave the lights on until the last person out turns them off, which the energy code accepts in some editions for an electrical room and not in others. A sensor that only turns the lighting off satisfies an automatic shutoff requirement and leaves the worker in control of turning it on; it turns the lights off on a worker who stands still in front of a lineup long enough for the sensor to time out, which a sensor that also turns them on recovers from on the first movement, at the cost of a sensor that switches the lights on for every door opening. The sensor's coverage and time delay are set under [[sync/lighting-controls]] so that a worker in the working space is within its view. {note}
−## The bonding conductor between the room ground bus and the building grounding electrode system shall be sized per NEC Table 250.66 and [[sync/grounding-and-bonding]].
+### Where an occupancy sensor is selected, the sensor shall cover the full working space of every lineup in the room with no part of the space outside its view, and its time delay shall be not less than 30 minutes.
−## Bonding of metallic doors, frames, ladders, racks, cable trays, ventilation ductwork, and any other metallic system within the room shall be performed per [[sync/grounding-and-bonding]].
+### The automatic shutoff of the room lighting shall comply with [[parameter: adopted-energy-code]] where that code requires it for an electrical equipment room.
−## Where the room contains telecommunications grounding equipment as a separate scope, the telecommunications ground bar shall be bonded to the building grounding electrode system per [[sync/telecommunications-bonding]] and shall not be mixed with the electrical room equipment ground bus.
+## Emergency Illumination {toc}
−# Equipment Anchorage and Seismic {toc}
+### Emergency illumination shall be provided in the working space of the service disconnecting means where it is installed indoors, and in the working space of the equipment of an emergency system, in accordance with NFPA 70 700.16, and shall not depend on the equipment whose working space it illuminates.
−## Equipment shall be anchored to resist the design lateral loads, and seismically certified where the seismic design category requires it.
+### The source of the emergency illumination in each room shall be as indicated in the datasheet.
−## The Seismic Design Category and the equipment seismic certification basis shall be as indicated in the datasheet.
−
```datasheet
−label: Seismic Design Category for Room
−type: select
−drawing_ref: "structural drawings"
+label: Emergency Illumination Source
+type: radio
options:
− - "A or B (no special anchorage)"
− - "C"
− - "D"
− - "E or F"
−default: deferred
+ - "A luminaire with an integral battery in the room"
+ - "A luminaire supplied from the emergency or legally required standby system"
```
+### A battery luminaire costs a unit and a battery that is replaced every few years, is independent of every circuit in the room and lights the room during the maintenance outage of the very equipment that supplies the emergency system; a luminaire on the emergency branch costs a circuit from the emergency panel, lasts as long as the building and is dark during a maintenance outage of the transfer switch or the emergency panel unless that panel is elsewhere. The battery unit is the choice in the room that holds the emergency system itself; the emergency branch is the choice in a room supplied from an emergency panel in another room. {note}
+
+### The emergency luminaires shall be furnished under [[sync/emergency-and-egress-lighting]] and shall illuminate the working space of every lineup in the room and the path from it to each entrance.
+
+## Convenience Receptacle {toc}
+
+### The convenience receptacle provision of each room shall be as indicated in the datasheet.
+
```datasheet
−label: Equipment Seismic Certification
−type: select
−drawing_ref: "structural drawings"
+label: Convenience Receptacle Provision
+type: radio
options:
− - "Not required by seismic design category"
− - "IBC/ASCE 7 — Importance Factor 1.0"
− - "IBC/ASCE 7 — Importance Factor 1.5 (essential facility)"
− - "OSHPD pre-approval (California healthcare)"
−default: deferred
+ - "One receptacle within 25 ft of the service equipment"
+ - "One receptacle within 25 ft of every lineup in the room"
+ - "One receptacle at each entrance to the working space"
```
−## The Seismic Design Category and the Importance Factor are established by the project's structural design; the electrical scope adopts them rather than setting them. {note}
+### NFPA 70 210.63 requires a 125 V, single-phase, 15 A or 20 A receptacle within 25 ft of indoor service equipment, which is what the first provision records and what a room that holds only the service needs. A receptacle within 25 ft of every lineup puts a test instrument, a work light and a vacuum within a cord's reach of every compartment in a long room, at the cost of a receptacle per lineup; a receptacle at each entrance puts the cord where the worker enters and where the lift truck is charged, at the cost of a receptacle per door, and in a two-door room covers most lineups by default. {note}
−## Equipment in electrical rooms shall be anchored to resist the design lateral loads per ASCE 7 and the applicable building code.
+### The receptacle shall not be supplied from the load side of the equipment whose working space it serves, so that the receptacle remains energized while that equipment is de-energized for maintenance.
−## Anchorage shall be coordinated with the structural design of the floor or housekeeping pad.
+### The receptacle shall be ground-fault circuit-interrupter protected where NFPA 70 210.8 requires it for the location, and shall be furnished under [[sync/wiring-devices]].
−## Where the building site is in a seismic design category that requires seismic certification of nonstructural components, the equipment shall be seismically certified per ICC ES AC156 by shake-table testing or by analysis per ASCE 7.
+### The receptacle shall be located outside the dedicated electrical space of every lineup, and shall not be mounted on the equipment enclosure.
−## Concrete housekeeping pads shall be provided beneath floor-mounted equipment, dimensioned to extend at least 3 in. beyond the equipment base on all sides and reinforced to receive the anchorage in accordance with the equipment manufacturer's published mounting details.
+## Lighting and Receptacle Circuit Source {toc}
−## Anchorage details shall be shown [[drawing: on the structural drawings or coordinated with the equipment shop drawings]].
+### The lighting and the receptacle circuits of the room shall be supplied from a panelboard outside the room or from a panelboard in the room that is not the equipment whose working space they serve, and shall not be supplied from the load side of the service disconnecting means or the main device of the lineup they illuminate.
−# Security and Access Control {toc}
+### A room whose lights and receptacles are fed from the main panelboard in the room goes dark the moment that panelboard is de-energized for maintenance, which is the moment the worker needs the lights most. The error is common because the main panelboard is the nearest source, and it is caught on the coordination drawing, where the circuit source is written beside each luminaire. {note}
−## Electrical rooms shall be secured against unauthorized entry while preserving free egress from the inside.
+# Housekeeping Pads and Floor {toc}
−## The means of controlling access to the room shall be as indicated in the datasheet.
+## Housekeeping Pad Provision {toc}
−```datasheet
−label: Access Control
−type: select
−options:
− - "Mechanical key"
− - "Electronic card or credential reader"
− - "Electronic reader with audit trail and remote enable/disable"
− - "Reader plus video surveillance"
−```
+### The housekeeping pad provision for the floor-standing equipment in each room shall be as indicated in the datasheet.
−## The intrusion detection provided at the room shall be as indicated in the datasheet.
−
```datasheet
−label: Intrusion Detection
+label: Housekeeping Pad Provision
type: radio
options:
− - "None"
− - "Door contact reported to BMS or security panel"
− - "Door contact plus interior motion sensor"
+ - "A housekeeping pad under every floor-standing lineup"
+ - "A housekeeping pad only where the equipment standard requires one"
+ - "No housekeeping pads"
+default: "A housekeeping pad under every floor-standing lineup"
```
−## The access control and intrusion detection levels follow the Owner's security program for the facility, so neither field carries a default. {note}
+### A pad under every lineup lifts every enclosure base above the water a sprinkler, a leak or a washdown puts on the floor, gives the conduits entering from below their bending radius, and gives the anchors a thickness of concrete the floor slab alone does not always have; it costs a pad per lineup and a step up to every enclosure. A pad only where the equipment standard requires one leaves a wall-hung panelboard and a transformer on a floor stand without one and puts the switchgear on one, which is what most of the equipment standards already ask. Setting equipment on the finished floor costs nothing and is chosen where the slab is thick enough to anchor into, where no water can reach the floor and where a lift truck has to roll up to every compartment without a ramp. {note}
−## Access shall be limited to qualified persons under NEC and to maintenance and operations personnel authorized by the building owner.
+### Every housekeeping pad shall be constructed under [[sync/concrete-pads]], at the height, projection and thickness that standard sets, and its plan dimensions shall be as indicated on [[drawing: the electrical room coordination drawing]].
−## Where the building employs an electronic access control system, the electrical room doors shall be on the system per [[sync/access-control-systems]].
+### Where a pad is provided under a lineup served by a lift truck, the surface in front of the lineup shall be at the pad surface or shall be ramped to it, as the standard for that lineup requires.
−## Where a mechanical key system is used, the keying shall be coordinated with the door hardware schedule and with the owner's key control policy.
+### The floor of the room shall be designed for the weight of the equipment and of the lift truck as indicated on [[drawing: the structural drawings]], and the Contractor shall report any equipment whose reviewed shipping weight exceeds the weight the structural drawings state before the equipment is delivered.
−## Free egress from the inside of the room shall not be impeded by any security device; locking devices that defeat panic hardware are prohibited per NFPA 101.
+### Every item of equipment in the room shall be anchored to the pad or the floor as its own standard requires, with the anchorage designed under [[sync/vibration-isolation-and-seismic-restraint]] where [[parameter: seismic-design-category]] requires nonstructural components to be restrained.
−## Mantraps and similar restrictive entry devices shall not be installed on electrical rooms unless specifically required by the owner and approved by the AHJ.
+## Floor Finish {toc}
−# Finishes {toc}
+### The floor finish of each room shall be as indicated in the datasheet.
−## Floor {toc}
−
−### The floor finish shall be as indicated in the datasheet.
−
```datasheet
label: Floor Finish
type: select
options:
- "Sealed concrete"
− - "Sealed concrete with anti-static topping"
− - "Epoxy coating"
− - "Resilient sheet flooring"
+ - "Resinous floor coating"
+ - "Static-dissipative resinous floor"
default: "Sealed concrete"
```
−### Resilient sheet flooring shall not be installed in a room containing switchgear, a switchboard, or a motor control center.
+### Sealed concrete costs a sealer rolled on the slab, does not dust, and is what most electrical rooms are given; a resinous floor coating costs a prepared slab and a fluid-applied system and buys a floor that cleans, that shows a leak and that resists the electrolyte of a vented battery; a static-dissipative resinous floor adds a ground connection and a controlled surface resistance and is chosen in a room of electronic relays, a control room or a battery room where the Owner's electrostatic discharge program asks for it. The resinous systems are furnished under [[sync/resinous-flooring]], and the ground connection of a static-dissipative floor is made under [[sync/grounding-and-bonding]]. {note}
−### Electrical room floors shall be sealed concrete or another smooth, non-absorbent, easily cleaned finish that does not generate dust and that does not retain moisture.
+### The floor finish shall be complete and cured before the equipment is set, and the floor under every lineup shall be level to the tolerance the equipment standard requires.
−### The floor shall be level under each equipment line-up to the tolerance required by the equipment manufacturer, typically 1/8 in. in 10 ft.
+### Carpet, resilient tile and any finish that sheds fibers or holds moisture shall not be installed in an electrical room.
−### Where mineral-oil-filled or fluid-cooled equipment is installed, the floor shall be sloped to the floor drain and provided with a containment curb sized to retain the equipment's fluid volume.
+# Grounding Provisions in the Room {toc}
−### Anti-static or static-dissipative floor finishes shall be provided in rooms with electronic protective relays, in battery rooms where qualified, and in rooms specifically designated for sensitive equipment.
+## The room ground bar provision shall be as indicated in the datasheet.
−### Carpeted floor finishes shall not be installed in electrical rooms.
−
−## Walls and Ceiling {toc}
−
−### The wall and ceiling finish shall be as indicated in the datasheet.
−
```datasheet
−label: Wall Finish
−type: select
+label: Room Ground Bar
+type: radio
options:
− - "Painted gypsum board on rated assembly"
− - "Painted concrete masonry unit"
− - "Painted concrete (exposed structure)"
+ - "A ground bar in every electrical room"
+ - "A ground bar only in a room that houses a separately derived system or more than one lineup"
+ - "Not provided"
```
−### Wall and ceiling finishes shall be non-combustible, low-dust, and compatible with the required fire-resistance rating.
+## A ground bar in every room gives the room one visible point where the equipment grounds, the grounding electrode taps of the derived systems and the bonding conductors of the doors, racks and trays are brought together and can be tested, at the cost of a bar, a bonding conductor sized to the largest system landed on it and a wall space; a bar only where a derived system or a second lineup exists spends that cost where there is more than one thing to tie together; no bar leaves each lineup's ground bus to do the work, which the code permits and which a closet with one panelboard rarely needs more than. {note}
−### Painted gypsum board, painted concrete masonry unit, and painted concrete are common wall and ceiling finishes. {note}
+## Where a ground bar is selected, it shall be a copper bar mounted on insulated standoffs at a height of 18 in. to 24 in. above the floor on a wall outside the working space, and shall be bonded to the grounding electrode system under [[sync/grounding-and-bonding]] by a conductor sized as that standard requires for the systems landed on it.
−### Acoustical ceiling tile is permitted outside the dedicated equipment space envelope, provided it is rated for the assembly and does not interfere with the rated boundary.
+## The metal doors, frames, ladders, racks and cable trays of the room shall be bonded to the ground bar or to the nearest equipment ground bus where [[sync/grounding-and-bonding]] selects that bonding, and the grounding electrode system serving the room shall be installed under that standard.
−# Signage {toc}
+## Where the room also houses telecommunications equipment, the telecommunications ground bar shall be installed and bonded under [[sync/telecommunications-bonding]] and shall not be used as the room ground bar of this standard.
−## The signage installed at the room entry shall be as indicated in the datasheet.
+# Room Signage {toc}
+## The signs installed on the entry door of each room shall be as indicated in the datasheet.
+
```datasheet
−label: Room Entry Signage
+label: Room Door Signs
type: checkbox
options:
− - "'High Voltage — Authorized Personnel Only' (over 1000 V)"
− - "'Danger — Electrical Hazard' at door"
− - "Arc-flash boundary warning at entrance"
− - "Available fault current and date (NEC 110.24)"
− - "No-smoking sign (battery rooms)"
+ - "Room identification sign"
+ - "Sign restricting entry to authorized persons"
+ - "Sign prohibiting storage in the room"
+ - "Arc-flash and shock hazard warning sign"
default:
− - "'Danger — Electrical Hazard' at door"
− - "Arc-flash boundary warning at entrance"
− - "Available fault current and date (NEC 110.24)"
+ - "Room identification sign"
+ - "Sign restricting entry to authorized persons"
+constraint: all_of
```
−## The room and its equipment shall be signed per NEC 110.16 (arc-flash hazard warning), per NEC 110.21 (equipment identification), and per the project equipment-labeling standard [[sync/equipment-labeling]].
+## The signs on the door are what a building's staff, its cleaners and its tenants read; the labels on the equipment inside are what the qualified person reads, and [[sync/equipment-labeling]] governs those. A room identification sign lets the responder and the facility staff find the room; a sign restricting entry keeps the unqualified out, which the code requires for a room over 1000 V and the Owner's safety program asks for on the rest; a storage sign is the cheapest defense of the working space; an arc-flash warning on the door tells the entering worker that the equipment inside carries incident energy labels before the door is opened, and it is chosen where the facility's electrical safety program under [[sync/electrical-safety-program]] uses it. {note}
−## Signage shall be durably affixed and legible from a distance equal to the working space depth.
+## Every entrance to a room that houses equipment rated over 1000 V shall carry a warning sign reading DANGER, HIGH VOLTAGE, KEEP OUT, in accordance with NFPA 70 110.34(C), whatever the datasheet selects.
−## Signs that are required by code shall not be obstructed by equipment, finishes, or accessory installations.
+## A sign that restricts entry, prohibits storage or warns of a hazard shall be a rigid plastic or aluminum sign in the signal word, color and layout of ANSI Z535.4, with characters not less than 1 in. high, fastened to the door or the wall beside it with its center 60 in. above the floor.
−# Cable Pathways {toc}
+## The room identification sign shall be fabricated and installed under [[sync/signage]] where the project has a sign schedule, and shall carry the room name and number shown on the electrical plans.
−## Conduit, cable tray, and busway entry shall be coordinated with the working space, the dedicated equipment space, and the rated-wall penetration locations.
+## No sign required by this standard or by [[sync/equipment-labeling]] shall be obstructed by a door in its open position, by equipment or by a finish.
−## The primary cable entry arrangement for each equipment line-up shall be as indicated in the datasheet.
+# Coordination Drawing {toc}
−```datasheet
−label: Primary Cable Entry
−type: radio
−drawing_ref: "electrical room layout drawings"
−options:
− - "Bottom entry (through floor or housekeeping pad)"
− - "Top entry (through ceiling)"
− - "Side entry (through wall)"
− - "Combination per equipment"
−default: deferred
−```
+## The electrical Contractor shall prepare a coordination drawing of each electrical room at a scale not smaller than 1/4 in. to 1 ft in plan and in elevation, from the reviewed shop drawings of every item of equipment in the room.
−## Conduit, cable tray, and busway entering and leaving the electrical room shall comply with [[sync/raceways-and-conduit]].
+## The coordination drawing shall show every lineup at its reviewed dimensions, the working space in front of, beside and behind each as the datasheet basis requires, the dedicated electrical space above and below each, the clear height of the room, every entrance with its swing and clear opening, the egress path, every housekeeping pad, every raceway, busway, cable tray, pipe, duct, louver and damper that enters or crosses the room, the arc exhaust plenum and its discharge where one exists, every luminaire with its circuit source, every receptacle with its circuit source, the ground bar, the cooling unit or ventilation openings, the floor drain and the curb where selected, and every sign on the door.
−## Cable entry zones shall be coordinated with the working-space envelope, the dedicated equipment space, and the rated-wall penetration locations.
+## The coordination drawing shall identify every foreign system in the room against the provision selected in the datasheet, and shall show the drip shield or protection below each one that is permitted.
−## Penetrations of rated wall, floor, and ceiling assemblies for cable pathways shall be sealed with listed firestop systems per [[sync/firestopping]].
+## The coordination drawing shall be issued to every trade that attends the coordination meeting, and no trade shall install work in the room that departs from it without a revision reviewed by the Engineer of Record.
−## Sleeves provided through cast-in-place concrete floors shall extend a minimum of 2 in. above finished floor where cable enters from above the floor so that water and debris on the floor do not enter the raceway system below.
+## Where the reviewed shop drawings of an item of equipment change its dimensions, its weight, its heat release or its clearances after the coordination drawing is reviewed, the Contractor shall revise and resubmit the coordination drawing before the equipment is delivered.
−# Coordination with Other Trades {toc}
+## A coordination drawing is the only document on which the working space, the dedicated space, the door swing, the egress path, the pads, the foreign systems and the circuit sources appear together at the equipment's real size, and it is the document a trade can be held to. A floor plan drawn before the shop drawings exist shows an equipment outline that the delivered equipment rarely matches. {note}
−## The electrical Contractor shall coordinate the following at minimum with the listed trades during shop drawing review and prior to room construction.
+# Field Verification {toc}
−- Architectural: room dimensions, finishes, doors and hardware, signage, accessibility path
−- Structural: housekeeping pads, equipment loads, seismic anchorage, slab depressions, equipment-pad reinforcement
−- Mechanical: ventilation airflow, intake and discharge louver locations, fire dampers at rated penetrations, room thermal load, condensate management
−- Plumbing: avoidance of foreign piping in the dedicated equipment space, floor drain location and trap priming, any required eyewash for battery rooms
−- Fire protection: sprinkler coverage and discharge characteristics in rooms with energized equipment, pre-action vs. wet-pipe selection, drain location for sprinkler test
−- Telecommunications: separation from telecom rooms, grounding interface with telecommunications bonding backbone per [[sync/telecommunications-bonding]]
−- Security: access control reader, lock, and door contact installation per [[sync/access-control-systems]]; video coverage where required
+## The Contractor shall verify and record the items indicated in the datasheet for each room, at the stage each item names, and shall transmit the record to the Engineer of Record before the equipment in the room is energized.
−## Conflicts identified during coordination shall be resolved before the affected scope proceeds.
−
−## Where a coordination conflict has no other resolution, the electrical room requirements of this standard and NEC Article 110 shall govern, because the room is a code-required envelope and other trades' routing is generally adjustable.
−
−# Commissioning {toc}
−
−## Each electrical room shall be commissioned as part of the integrated systems testing of the building.
−## Commissioning of the room itself, distinct from the equipment within it, shall verify the following at minimum.
−
−- Working space dimensions verified by direct measurement against the approved layout
−- Dedicated equipment space envelope clear of foreign systems
−- Door swing, panic hardware, and egress lighting functional
−- Lighting illuminance measured at the working plane and compared to the design value
−- Ventilation airflow measured at intake and discharge, including any fire damper actuation tests
−- Room temperature held to setpoint with the connected load at the project commissioning load case
−- Ground bus bonded and resistance to the building grounding electrode system verified
−- Convenience receptacles functional, GFCI test-trip-reset confirmed
−- Access control functional, audit trail recording confirmed where applicable
−- Signage installed, complete, and legible
−
```datasheet
−label: Commissioning Scope
+label: Field Verification of the Room
type: checkbox
options:
− - "Working-space dimension verification"
− - "Dedicated equipment space verification"
− - "Door swing, panic hardware, egress lighting"
− - "Illumination measurement at working plane"
− - "Ventilation airflow and fire-damper testing"
− - "Temperature verification under load"
− - "Ground bus and bonding verification"
− - "Receptacle and GFCI testing"
− - "Access control functional and audit verification"
− - "Signage verification"
+ - "Working space depth, width and height measured at every lineup after the equipment is set"
+ - "Dedicated electrical space clear of foreign systems before the ceiling is closed"
+ - "Clear height measured before the equipment is delivered"
+ - "Door swing, clear opening, panic hardware and free egress verified"
+ - "Illuminance measured at the working plane of every lineup"
+ - "Room air temperature held within the limits with the equipment loaded"
+ - "Ventilation airflow or cooling capacity measured against the calculation"
+ - "Floor drain, curb and drip shields verified where selected"
+ - "Receptacle location, source and GFCI operation verified"
+ - "Ground bar bonding verified"
+ - "Door signs installed and legible"
default:
− - "Working-space dimension verification"
− - "Dedicated equipment space verification"
− - "Door swing, panic hardware, egress lighting"
− - "Illumination measurement at working plane"
− - "Ventilation airflow and fire-damper testing"
− - "Temperature verification under load"
− - "Ground bus and bonding verification"
− - "Receptacle and GFCI testing"
− - "Signage verification"
+ - "Working space depth, width and height measured at every lineup after the equipment is set"
+ - "Dedicated electrical space clear of foreign systems before the ceiling is closed"
+ - "Door swing, clear opening, panic hardware and free egress verified"
+ - "Illuminance measured at the working plane of every lineup"
+ - "Receptacle location, source and GFCI operation verified"
+ - "Door signs installed and legible"
+constraint: all_of
```
−## Commissioning reports shall be incorporated into the closeout submittals.
+## The working space shall be measured with a tape from the as-set enclosure faces and recorded against the depth, width and height the datasheet basis requires, and any deficiency shall be corrected by relocating the obstruction, not by accepting the measured value.
−# Delivery, Storage, and Handling (During Construction) {toc}
+## The illuminance shall be measured with a calibrated meter on a vertical plane at the equipment face at the height of the device handles, with the room's normal lighting on and daylight excluded, and the measured value shall be not less than the datasheet value.
−## The electrical room shall not be used for storage of construction materials, tools, or trades' equipment beyond what is required to complete the work of the room itself.
+## The room air temperature shall be measured at the intake of the equipment with the highest heat release, with the room's equipment carrying not less than the load available at the time of the verification and the ventilation or cooling in normal operation, and the trade responsible for the room's ventilation or cooling shall demonstrate by calculation from the measured values that the room holds the datasheet limits at the heat-release basis.
−## Equipment delivered to the room before the room is enclosed and conditioned shall be protected from weather, dust, and moisture per the equipment manufacturer's storage requirements.
+## The ventilation airflow shall be measured under [[sync/testing-adjusting-and-balancing]] and the cooling unit capacity verified under the standard for that unit, and this standard requires only that the result be recorded against the room calculation.
−## Where the room becomes enclosed but is not yet conditioned, condensation heaters in the equipment shall be energized from a temporary source.
+## Where a verification finds a deficiency, the Contractor shall correct it at no change in the contract sum and shall repeat the verification, and the cost of a repeat verification shall be borne by the Contractor.
−## During construction, the working space and dedicated equipment space of installed equipment shall be respected by all trades, even where finished construction is not yet complete.
+## The field verification of the room shall be folded into the total building commissioning program under [[sync/commissioning]] where the project has one, and shall be performed under this standard where it does not.
−## Installation of foreign piping, ductwork, or finishes that would later require removal to comply with NEC 110.26 shall not proceed.
+## The measurements this section requires are the ones an Authority Having Jurisdiction takes with a tape and a light meter on the day of the final inspection, and a room that fails one of them then is a room whose ceiling is reopened and whose duct is moved on the last week of the project. Taking them when the equipment is set, with the ceiling still open, is what makes them cheap. {note}
−# Warranty {toc}
+# Protection of the Room During Construction {toc}
−## The warranty period for room-specific products shall be as indicated in the datasheet.
+## The electrical room shall not be used for the storage of construction materials, tools or the equipment of any trade, other than the electrical equipment that is set in its final position and the material needed to complete the room itself.
−```datasheet
−label: Room-Specific Product Warranty Period
−type: select
−options:
− - "1 year from substantial completion"
− - "2 years from substantial completion"
−default: "1 year from substantial completion"
−```
+## Electrical equipment delivered to a room before the room is enclosed and dry shall be protected from weather, dust and moisture as its own standard requires, and the space heaters of any equipment that has them shall be energized from a temporary source from the day the equipment is set.
−## The Contractor shall warrant the room installation including doors, hardware, finishes, lighting, ventilation, drainage, ground bus and bonding, and signage, for the project warranty period.
+## No equipment with electronic components shall be set in a room until the room is enclosed, its roof or the floor above it is watertight, and the dust-producing work of the other trades in the room is complete.
−## Products carrying a manufacturer warranty shall be warranted to the Owner for the manufacturer's published warranty period.
+## The working space and the dedicated electrical space of every lineup shall be respected by every trade from the day the equipment is set, and no pipe, duct, hanger or finish that would later have to be removed to satisfy this standard shall be installed.
+
+## Where the room's permanent ventilation or cooling is not in service when the equipment is energized, temporary ventilation or cooling holding the datasheet limits shall be provided until it is.