Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
---
title: Electrical Service Entrance
category: Electrical / Power Distribution Equipment
toc_depth: 3
description: >
− When to use: design, specification, and installation of low-voltage (600 V class) electrical
− service entrances for commercial, industrial, and multi-family residential buildings — from the
− utility point of delivery through the service disconnecting means. Covers overhead service drops
− and underground laterals, service-entrance conductors, weatherheads and risers, meter sockets and
− metering enclosures, combination service-entrance devices (CSEDs / meter-mains), service
− disconnects, ground-fault protection of equipment (GFPE), emergency disconnects, service
− enclosures, and the utility-to-owner interface, for new construction and service upgrades at
− 120/240 V 1Φ, 120/208 V 3Φ, and 277/480 V 3Φ.
− Not intended for: distribution switchboards and switchgear downstream of the service disconnect
− (use [[sync/low-voltage-switchboards]]); service-point and pad-mounted transformers (use
− [[sync/transformers]]); grounding electrode conductors, ground rods, and bonding jumpers (use
− [[sync/grounding-and-bonding]]); revenue metering instruments and power monitoring beyond the
− basic utility meter socket (use [[sync/electrical-power-monitoring]]); motor starters and branch
− overcurrent devices (use [[sync/combination-motor-starters]]); generator paralleling and automatic
− transfer switches at the service entrance; and medium-voltage (>600 V) primary services and
− primary metering.
+ When to use: design, specification, and installation of low-voltage (600 V class) electrical service entrances for commercial, industrial, and multi-family residential buildings — from the utility point of delivery through the service disconnecting means. Covers overhead service drops and underground laterals, service-entrance conductors, weatherheads and risers, meter sockets and metering enclosures, combination service-entrance devices (CSEDs / meter-mains), service disconnects, ground-fault protection of equipment (GFPE), emergency disconnects, service enclosures, and the utility-to-owner interface, for new construction and service upgrades at 120/240 V 1Φ, 120/208 V 3Φ, 277/480 V 3Φ, and other 600 V class utility services.
+ Not intended for: distribution switchboards and switchgear downstream of the service disconnect (use [[sync/low-voltage-switchboards]]); service-point and pad-mounted transformers (use [[sync/medium-voltage-transformers]]); grounding electrode conductors, ground rods, and bonding jumpers (use [[sync/grounding-and-bonding]]); revenue metering instruments and power monitoring beyond the basic utility meter socket (use [[sync/electrical-power-monitoring]]); motor starters and branch overcurrent devices (use [[sync/combination-motor-starters]]); generator paralleling and automatic transfer switches at the service entrance; and medium-voltage (>600 V) primary services and primary metering.
---
…10 unchanged lines
## The work shall comply with NFPA 70 (NEC) Article 230, the serving utility's electric service requirements manual, and the authority having jurisdiction.
−## Where the serving utility's published requirements are more restrictive than this standard, the utility's requirements shall govern for all equipment on the utility side of the point of delivery, including metering provisions. {note}
+## Where the serving utility's published requirements are more restrictive than this standard, the utility's requirements shall govern for all equipment on the utility side of the point of delivery, including metering provisions.
## Utilities maintain approved-equipment lists, meter-socket jaw configurations, current-transformer ratios, and mounting-height rules that override a generic specification. Confirming these before rough-in is a recurring source of rejected work when skipped. {note}
…11 unchanged lines
| Standard | Title |
|----------|-------|
−| NFPA 70 (NEC) 2023, Article 230 | Services — Service Conductors and Equipment |
−| NEC 2023, 230.42 | Minimum Size and Ampacity of Service-Entrance Conductors |
−| NEC 2023, 230.70 | Service Disconnecting Means — General |
−| NEC 2023, 230.71 | Maximum Number of Disconnects |
−| NEC 2023, 230.85 | Emergency Disconnects (one- and two-family dwellings) |
−| NEC 2023, 230.95 | Ground-Fault Protection of Equipment |
−| NEC 2023, Table 300.5 | Minimum Cover Requirements for Underground Installations |
−| NEC 2023, Table 310.12 | Single-Phase Dwelling Services and Feeders |
+| NFPA 70 | National Electrical Code (Article 230 — Services) |
+| NFPA 70E | Standard for Electrical Safety in the Workplace |
+| IEEE C2 | National Electrical Safety Code (NESC) |
| UL 869A | Reference Standard for Service Equipment |
| UL 414 | Meter Sockets |
| UL 67 | Panelboards |
−| UL 489 | Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit Breaker Enclosures |
+| UL 489 | Molded-Case Circuit Breakers, Molded-Case Switches, and Circuit-Breaker Enclosures |
| UL 98 | Enclosed and Dead-Front Switches |
+| NEMA 250 | Enclosures for Electrical Equipment (1000 Volts Maximum) |
| ANSI/NEMA PB 2 | Deadfront Distribution Switchboards |
−| IEEE C2 (NESC) 2023 | National Electrical Safety Code |
−| NFPA 70E 2024 | Standard for Electrical Safety in the Workplace |
+| ASCE 7 | Minimum Design Loads and Associated Criteria for Buildings and Other Structures |
# Utility Coordination and Point of Delivery {toc}
−## The point of delivery (POD) is the location where the serving utility's conductors terminate and ownership transfers to the customer; it shall be identified on the contract drawings. {note}
+## The point of delivery (POD) is the location where the serving utility's conductors terminate and ownership transfers to the customer. {note}
## For an overhead service, the POD is typically the service-drop attachment point at the weatherhead. For an underground service, it is typically the secondary terminals of the utility transformer or a designated junction. The POD divides NESC-governed (utility) work from NEC-governed (customer) work; misplacing it produces scope disputes and double-counted or orphaned equipment. {note}
+## The point of delivery shall be [[drawing: as indicated on the electrical site plan]].
+
## The Contractor shall obtain the serving utility's current electric service requirements manual before specifying or ordering any service equipment.
## The Contractor shall submit the utility service application and obtain utility approval of the service-entrance arrangement before commencing rough-in.
−## The available fault current (AFC) at the service point shall be requested in writing from the serving utility during design and shall not be assumed. {note}
+## The available fault current at the service point shall be requested in writing from the serving utility during design.
−## The AFC sets the minimum short-circuit current rating (SCCR / AIC) for all service equipment. Specifying equipment with an AIC below the actual utility fault current is a safety defect, not merely a code violation; it cannot be discovered by inspection of a nameplate alone and must be designed against from a utility-furnished value. {note}
+## An assumed or rule-of-thumb fault current is not an acceptable basis for service-equipment selection. The AFC sets the minimum short-circuit current rating (SCCR / AIC) for all service equipment. Specifying equipment with an AIC below the actual utility fault current is a safety defect, not merely a code violation; it cannot be discovered by inspection of a nameplate alone and must be designed against from a utility-furnished value. {note}
## The metering arrangement — self-contained (socket) metering or current-transformer (CT) metering — shall be coordinated with the serving utility, and CT ratios shall match the utility's revenue meter and data-acquisition requirements.
−## Utility easement and right-of-way constraints for underground lateral routing and transformer pad placement shall be coordinated with the civil and site work before the service location is fixed. {note}
+## Utility easement and right-of-way constraints for underground lateral routing and transformer pad placement shall be coordinated with the civil and site work before the service location is fixed.
+## The service entry type shall be as indicated in the datasheet.
+
```datasheet
label: Service entry type
type: radio
+drawing_ref: "electrical site plan"
options:
- Overhead service drop (weatherhead and riser)
- Underground service lateral
−default: Underground service lateral
−```
−
−```datasheet
−label: Point of delivery location
−type: text
−drawing_ref: true
default: deferred
```
# Service Characteristics {toc}
−## The service voltage, phase configuration, and number of wires shall match the serving utility's available distribution and the building's calculated load. {note}
+## The service voltage, phase configuration, and number of wires shall match the serving utility's available distribution and the building's calculated load.
−## Three configurations dominate low-voltage services: 120/240 V single-phase three-wire (most residential and light commercial), 120/208 V three-phase four-wire (commercial with mixed lighting and three-phase motor load), and 277/480 V three-phase four-wire (larger commercial and industrial, where 277 V lighting and 480 V motors reduce conductor size and losses). The main disconnect voltage rating shall match the system voltage per NEC 230.82. {note}
+## Three configurations dominate low-voltage services: 120/240 V single-phase three-wire (most residential and light commercial), 120/208 V three-phase four-wire (commercial with mixed lighting and three-phase motor load), and 277/480 V three-phase four-wire (larger commercial and industrial, where 277 V lighting and 480 V motors reduce conductor size and losses). Three-wire delta and high-leg delta services remain in service on older commercial and industrial premises and are still offered by some utilities. {note}
+## The main disconnect voltage rating shall match the system voltage per NEC 230.82.
+
## A single service shall supply the building unless the conditions of NEC 230.2 for additional services are met and documented.
+## The service voltage and phase configuration shall be as indicated in the datasheet.
+
```datasheet
label: Service voltage and phase
type: radio
+drawing_ref: "one-line diagram"
options:
- 120/240 V 1Φ 3-wire
- 120/208 V 3Φ 4-wire
+ - 120/240 V 3Φ 4-wire (high-leg delta)
+ - 240 V 3Φ 3-wire (delta)
- 277/480 V 3Φ 4-wire
−default: 120/208 V 3Φ 4-wire
+ - 480 V 3Φ 3-wire (delta)
+default: deferred
```
+## The service ampacity shall be as indicated in the datasheet and shall be not less than the calculated load determined under NEC Article 220.
+
```datasheet
label: Service ampacity (main disconnect rating)
−type: select
+type: range
unit: A
+drawing_ref: "one-line diagram"
options:
− - "100"
− - "200"
− - "400"
− - "600"
− - "800"
− - "1200"
− - "1600"
− - "2000"
− - "3000"
−default: "200"
+ min: 60
+ max: 6000
+ setpoints: [60, 100, 125, 150, 200, 225, 300, 400, 600, 800, 1000, 1200, 1600, 2000, 2500, 3000, 4000, 5000, 6000]
+default: deferred
```
+## The utility-declared available fault current at the service point shall be as indicated in the datasheet.
+
```datasheet
label: Available fault current (utility-declared, symmetrical)
type: range
unit: kA
−min: 10
−max: 65
−step: 1
−default: 42
+drawing_ref: "one-line diagram"
+options:
+ min: 5
+ max: 200
+ step: 1
+default: deferred
```
…2 unchanged lines
```datasheet
label: Minimum equipment short-circuit current rating (AIC)
−type: select
+type: range
unit: kAIC
options:
− - "22"
− - "42"
− - "65"
− - "100"
−default: "65"
+ min: 10
+ max: 200
+ setpoints: [10, 14, 18, 22, 25, 35, 42, 50, 65, 85, 100, 150, 200]
```
+## The equipment rating is selected as the first standard interrupting rating at or above the utility-declared fault current, so no rating is correct for every project and the field carries no default. {note}
+
# Submittals {toc}
…71 unchanged lines
## The Engineer of Record shall verify that the equipment SCCR shown on submittals equals or exceeds the utility-declared available fault current before approving the equipment for fabrication.
−## All service equipment shall bear the labeling required by NEC 110.24 for available fault current and the date of calculation. {note}
+## All service equipment shall bear the labeling required by NEC 110.24 for available fault current and the date of calculation.
# Environmental and Service Conditions {toc}
−## The service-equipment enclosure NEMA rating shall suit the installed environment. {note}
+## The service-equipment enclosure rating shall suit the installed environment.
−## Outdoor and exterior-wall installations require a minimum NEMA 3R rainproof enclosure. NEMA 1 general-purpose enclosures are acceptable only indoors in dry locations. Wet, washdown, coastal, or chemically corrosive environments require NEMA 4 or NEMA 4X (stainless or non-metallic). Specifying NEMA 1 for an exterior meter socket is a common and avoidable inspection rejection. {note}
+## Outdoor and exterior-wall installations require a minimum NEMA 3R rainproof enclosure. NEMA 1 general-purpose enclosures are acceptable only indoors in dry locations, and NEMA 12 is the indoor industrial choice where airborne dust and falling liquids are present. Wet, washdown, coastal, or chemically corrosive environments require NEMA 4 or NEMA 4X (stainless or non-metallic). Specifying NEMA 1 for an exterior meter socket is a common and avoidable inspection rejection. {note}
−## Equipment shall be rated for the ambient temperature range and altitude of the installation, and conductor ampacity shall be corrected for ambient temperature per NEC 310.
+## Equipment shall be rated for the ambient temperature range and altitude of the installation.
+## Conductor ampacity shall be corrected for ambient temperature per NEC Article 310.
+
+## The enclosure environmental rating shall be as indicated in the datasheet.
+
```datasheet
label: Enclosure environmental rating
…4 unchanged lines
- NEMA 4 (watertight)
- NEMA 4X (watertight, corrosion-resistant)
−default: NEMA 3R (outdoor, rainproof)
+ - NEMA 12 (indoor industrial, dust-tight)
```
+## The enclosure rating is an assessment of the actual installation environment made by the Engineer; indoor and outdoor service entrances are both routine, so no rating is correct for every project and the field carries no default. {note}
+
# Service-Entrance Conductors {toc}
−## Service-entrance conductors shall be sized to carry the calculated load per NEC 230.42 and shall be not smaller than the minimum required for the service rating. {note}
+## Service-entrance conductors shall be sized to carry the calculated load per NEC 230.42.
## Conductor ampacity is determined from the Article 220 load calculation for commercial work, or from NEC Table 310.12 for single-phase dwelling services (which permits an 83% demand factor). The 2023 NEC restructured 230.42 into subsections (A)(1) and (A)(2), clarifying how continuous/noncontinuous load factors and the ampacity adjustment and correction factors are applied — an update that can increase the required conductor size relative to prior editions. {note}
## Service-entrance conductors shall not be smaller than required for a 100 A service for a one-family dwelling per NEC 230.79(C).
−## Where aluminum conductors are used, the service-equipment terminations shall be listed for aluminum (AL/CU), and the connections shall be made with antioxidant compound and torqued to the manufacturer's published values. {note}
+## Where aluminum conductors are used, the service-equipment terminations shall be listed for aluminum (AL/CU).
+## Aluminum conductor connections shall be made with antioxidant compound and torqued to the manufacturer's published values.
+
## Aluminum is routinely specified for service conductors on cost and weight grounds, but a copper-only termination on aluminum conductors, or an untreated/under-torqued aluminum connection, produces a high-resistance joint that overheats. Confirming the termination rating is a specification responsibility, not a field assumption. {note}
## Conductors installed in conduit shall comply with the conduit-fill limits of NEC Chapter 9, Table 1.
+## The service-entrance conductor material shall be as indicated in the datasheet.
+
```datasheet
label: Service-entrance conductor material
…2 unchanged lines
- Copper
- Aluminum
−default: Aluminum
```
+## Copper and aluminum service-entrance conductors are both routinely specified and procurable; the choice turns on installed cost, available raceway size, and the owner's maintenance preference, so the field carries no default. {note}
+
+## The conductor insulation type shall be as indicated in the datasheet and shall be listed for the wiring method and for wet locations where the raceway is in a wet location.
+
```datasheet
label: Conductor insulation type
…4 unchanged lines
- THWN-2
- USE-2 (underground)
− - SER cable
−default: XHHW-2
+ - SEU cable (service-entrance, unarmored)
+ - SER cable (service-entrance, round)
```
+## The service-entrance conductor size shall be as indicated in the datasheet.
+
```datasheet
label: Service-entrance conductor size
type: text
−drawing_ref: true
+drawing_ref: "one-line diagram"
default: deferred
```
# Overhead Service {toc}
−## Where an overhead service is provided, a weatherhead shall terminate the service-entrance raceway above the service-drop attachment, with drip loops formed in the conductors. {note}
+## Where an overhead service is provided, a weatherhead shall terminate the service-entrance raceway above the service-drop attachment.
+## Drip loops shall be formed in the service-entrance conductors at the weatherhead.
+
## The weatherhead and conduit riser carry the service-entrance conductors from the meter up to the utility's service-drop splice. The drip loop and the weatherhead's downward-facing, gasketed openings keep water from tracking into the raceway and the meter enclosure. {note}
## The service-drop point of attachment shall be not less than 3.0 m (10 ft) above finished grade at the electrical service-entrance conductors per NEC 230.26.
−## Overhead service-drop conductors shall maintain the minimum vertical clearances above grade, driveways, and roadways established by the NEC and NESC. {note}
+## Overhead service-drop conductors shall maintain the minimum vertical clearances above grade, driveways, and roadways established by the NEC and NESC.
## The governing minimums are 3.0 m (10 ft) above grade at the service point, 3.7 m (12 ft) above residential driveways, and 5.5 m (18 ft) above public streets and roads. These are utility-side (NESC) clearances that constrain where the attachment and riser can be placed; they must be confirmed against site conditions before the riser location is fixed. {note}
+## The service-drop attachment height shall be as indicated in the datasheet.
+
```datasheet
label: Service-drop attachment height above grade
type: range
unit: ft
−min: 10
−max: 30
−step: 1
−default: 12
+drawing_ref: "electrical riser diagram"
+options:
+ min: 10
+ max: 30
+ step: 1
+default: deferred
```
+## The riser conduit material shall be as indicated in the datasheet.
+
```datasheet
label: Riser conduit material (overhead)
…6 unchanged lines
```
+## Rigid metal conduit is the default because it satisfies every serving utility's riser requirement and needs no evaluation for physical damage; IMC and Schedule 80 PVC are accepted by many utilities and are selected where weight or corrosion argues for them. {note}
+
# Underground Service {toc}
−## Where an underground service lateral is provided, the service-entrance conductors shall be installed in raceway or as listed underground cable at the minimum cover required by NEC Table 300.5. {note}
+## Where an underground service lateral is provided, the service-entrance conductors shall be installed in raceway or as listed underground cable.
−## The minimum cover depends on the wiring method: 600 mm (24 in.) for direct-buried USE-2 cable, rigid metal conduit, IMC, and rigid nonmetallic conduit at residential and light-commercial services. Schedule 40 PVC at 600 mm (24 in.) depth is the most common arrangement. HDPE duct and concrete-encased ducts have their own listed cover values. {note}
−
## Underground conductors shall be type USE-2 or installed in raceway with conductors listed for wet locations, since the interior of an underground raceway is a wet location.
−## Where service raceways enter a building from underground, the raceway shall be sealed against the entry of moisture, gases, and vermin per NEC 230.8. {note}
−
## A duct-seal or listed sealing fitting at the building entry is required by code and is frequently omitted; without it, soil gases and condensation track into the service equipment and corrode terminations. {note}
+## The underground raceway material shall be as indicated in the datasheet.
+
```datasheet
label: Underground raceway material
…2 unchanged lines
- Rigid PVC Schedule 40
- Rigid PVC Schedule 80
+ - Rigid PVC in concrete-encased duct bank
- HDPE duct
+ - Intermediate metal conduit (IMC)
- Rigid metal conduit (RMC)
−default: Rigid PVC Schedule 40
```
+## The raceway material for an underground lateral is normally dictated by the serving utility's service requirements manual and by the burial condition, so no material is correct for every project and the field carries no default. {note}
+
+## Cover over the underground service lateral shall be not less than required by NEC Table 300.5 for the wiring method and installation condition, and shall be not less than the cover indicated in the datasheet.
+
```datasheet
label: Minimum cover (underground service)
type: range
unit: in
−min: 18
−max: 36
−step: 1
−default: 24
+options:
+ min: 6
+ max: 48
+ step: 1
```
−```datasheet
−label: Underground lateral routing
−type: text
−drawing_ref: true
−default: deferred
−```
+## The minimum cover depends on the wiring method: 600 mm (24 in.) for direct-buried USE-2 cable, and 450 mm (18 in.) for rigid nonmetallic conduit at residential and light-commercial services. Schedule 40 PVC at 600 mm (24 in.) depth is the most common arrangement. Rigid metal conduit, IMC, HDPE duct, and concrete-encased ducts each have their own listed cover values, and cover under a building slab or a roadway differs again — so the field carries no default and the NEC table governs the floor. {note}
+## Underground lateral routing shall be [[drawing: as indicated on the electrical site plan]].
+
# Metering {toc}
−## A meter socket or metering enclosure shall be provided in conformance with the serving utility's requirements, listed to UL 414, and positioned for the utility's access. {note}
+## A meter socket or metering enclosure shall be provided in conformance with the serving utility's requirements, listed to UL 414, and positioned for the utility's access.
## The meter socket type — ringless or ring-type, four-jaw or five-jaw, single-position or multi-position — is dictated by the serving utility, not the engineer. Self-contained (socket) metering is used up to 200 A class; larger services and many commercial services use CT metering, where current transformers feed an instrument-grade meter socket. Specifying a socket configuration the utility will not accept forces a field change at the worst possible time. {note}
## Self-contained meter sockets shall be provided with a bypass provision where required by the serving utility to permit meter replacement without interrupting service.
−## For services above the self-contained metering limit, a current-transformer metering compartment shall be provided with CT ratios matched to the utility's revenue meter. {note}
+## For services above the self-contained metering limit, a current-transformer metering compartment shall be provided with CT ratios matched to the utility's revenue meter.
−## Multi-tenant buildings requiring individual tenant metering shall be provided with gang (multi-position) meter stacks, with each position rated for the tenant service ampacity. {note}
+## Multi-tenant buildings requiring individual tenant metering shall be provided with gang (multi-position) meter stacks, with each position rated for the tenant service ampacity.
−## Two- through six-position meter stacks serve multifamily and multi-tenant buildings, each position typically 100 A to 200 A. Each tenant position is a separate service or a separate disconnect grouping and must be labeled to identify the load served. {note}
+## Two- through six-position meter stacks serve small multifamily and multi-tenant buildings, each position typically 100 A to 200 A; modular metering centers extend the same arrangement to considerably larger unit counts. Each tenant position is a separate service or a separate disconnect grouping and must be labeled to identify the load served. {note}
−## The meter shall be mounted so the center of the meter is at the height above finished grade required by the serving utility, typically between 1.1 m (3.5 ft) and 1.8 m (6 ft).
+## The metering type shall be as indicated in the datasheet.
```datasheet
label: Metering type
type: radio
+drawing_ref: "one-line diagram"
options:
- Self-contained socket meter (200 A class)
- CT metering (current-transformer compartment)
- Multi-position gang meter stack
−default: Self-contained socket meter (200 A class)
+default: deferred
```
+## The meter socket configuration shall be as indicated in the datasheet.
+
```datasheet
label: Meter socket configuration
…2 unchanged lines
- Ringless
- Ring-type
−default: Ringless
```
+## The socket configuration is set by the serving utility's approved-equipment list rather than by the Engineer, so the field carries no default and is answered from the utility's service requirements manual. {note}
+
+## The number of metering positions shall be as indicated in the datasheet.
+
```datasheet
−label: Number of metering positions (gang stacks)
+label: Number of metering positions
type: range
unit: position
−min: 1
−max: 6
−step: 1
−default: 1
+drawing_ref: "one-line diagram"
+options:
+ min: 1
+ max: 24
+ step: 1
+default: deferred
```
+## The meter shall be mounted so the center of the meter is at the height above finished grade indicated in the datasheet.
+
```datasheet
label: Meter center height above finished grade
type: range
unit: ft
−min: 3.5
−max: 6
−step: 0.5
−default: 5
+options:
+ min: 3
+ max: 6.5
+ step: 0.5
```
+## Serving utilities publish their own meter-height window — commonly between 1.1 m (3.5 ft) and 1.8 m (6 ft) to the meter center — so the height is read from the utility's service requirements manual and the field carries no default. {note}
+
# Service Disconnecting Means {toc}
−## A means to disconnect all ungrounded service conductors from the building shall be provided per NEC 230.70. {note}
+## A means to disconnect all ungrounded service conductors from the building shall be provided per NEC 230.70.
## The service disconnect is the building's main "off" switch and the dividing point at which utility power can be removed from the premises wiring. It may be a molded-case main circuit breaker (UL 489), a fusible switch (UL 98), or the main section of a service-entrance switchboard (ANSI/NEMA PB 2). {note}
−## The service disconnect shall be installed at the nearest practicable point to the entrance of the service conductors, either outside the building or inside nearest the point of entrance per NEC 230.70(A)(1). {note}
+## The service disconnect shall be installed at the nearest practicable point to the entrance of the service conductors, either outside the building or inside nearest the point of entrance per NEC 230.70(A)(1).
## Excess service-conductor length inside the building between the meter and the main disconnect is unprotected by the service overcurrent device and is a frequent inspection rejection. An exterior disconnect is preferred where practicable because it lets first responders de-energize the building without entering it. {note}
…3 unchanged lines
## A single service disconnect should be provided for each service.
−## NEC 230.71 permits up to six service disconnects in a grouping for certain individual-occupancy arrangements, but a single main disconnect is the clearer and more defensible design for most commercial buildings and avoids ambiguity about which switch removes all service power. Multiple-disconnect groupings should be reserved for genuine multi-occupancy conditions and shall meet all conditions of 230.71. {note}
+## Multiple-disconnect groupings shall meet all conditions of NEC 230.71.
−## The disconnecting means shall be listed and rated for use as service equipment, with a short-circuit current rating not less than the available fault current.
+## NEC 230.71 permits up to six service disconnects in a grouping for certain individual-occupancy arrangements, but a single main disconnect is the clearer and more defensible design for most commercial buildings and avoids ambiguity about which switch removes all service power. Multiple-disconnect groupings are best reserved for genuine multi-occupancy conditions. {note}
+## The disconnecting means shall be listed and rated for use as service equipment.
+
+## The service disconnect device type shall be as indicated in the datasheet.
+
```datasheet
label: Service disconnect device type
type: radio
options:
- Main circuit breaker (molded-case)
+ - Main circuit breaker (insulated-case or power circuit breaker)
- Fusible switch
- Switchboard main section
−default: Main circuit breaker (molded-case)
```
+## A molded-case main breaker, a fusible switch, and a switchboard main section are all routinely specified service disconnects; the choice turns on the service ampacity, the interrupting rating required, and whether current-limiting fuses are wanted, so the field carries no default. {note}
+
+## The number of service disconnects shall be as indicated in the datasheet.
+
```datasheet
label: Number of service disconnects
…7 unchanged lines
# Combination Service-Entrance Devices {toc}
−## Where a combination service-entrance device (CSED / meter-main) is provided, it shall integrate the meter socket and the service disconnect in a single listed enclosure rated for the service entry method. {note}
+## Where a combination service-entrance device (CSED / meter-main) is provided, it shall integrate the meter socket and the service disconnect in a single listed enclosure rated for the service entry method.
## A CSED combines the meter socket and the main breaker (and often a small panelboard) in one outdoor- or underground-rated enclosure. It is the standard arrangement for residential and light-commercial services up to about 400 A and reduces the conductor run between meter and disconnect to a minimum. {note}
−## A CSED shall not be specified for services above its listed maximum rating; services exceeding the CSED range shall use a separate meter socket and switchboard or switchgear arrangement. {note}
+## A CSED shall not be specified for services above its listed maximum rating.
+## Services exceeding the CSED range shall use a separate meter socket and switchboard or switchgear arrangement.
+
## Most CSEDs are listed only to 400 A. Specifying a single meter-main for a larger service is a recurring design error that surfaces as a procurement dead-end; above the CSED range the meter and the disconnect become separate assemblies. {note}
+## The service-entrance assembly type shall be as indicated in the datasheet.
+
```datasheet
label: Service-entrance assembly type
type: radio
+drawing_ref: "one-line diagram"
options:
- Separate meter socket and main disconnect
- Combination service-entrance device (CSED / meter-main)
- Service-entrance switchboard section
−default: Separate meter socket and main disconnect
+default: deferred
```
# Ground-Fault Protection of Equipment {toc}
−## Ground-fault protection of equipment (GFPE) shall be provided on each service disconnect rated 1000 A or more on a solidly grounded wye service of more than 150 V to ground but not exceeding 600 V phase-to-phase, per NEC 230.95. {note}
+## Ground-fault protection of equipment (GFPE) shall be provided on each service disconnect rated 1000 A or more on a solidly grounded wye service of more than 150 V to ground but not exceeding 600 V phase-to-phase, per NEC 230.95.
## In practice this means GFPE is required on 480Y/277 V services with a service disconnect of 1000 A or larger. GFPE detects a phase-to-ground fault that is too small to trip the overcurrent device quickly but large enough to do severe arcing damage, and it opens the disconnect on that ground current alone. The most common coordination failure is when the main switchboard is specified by a different section and GFPE is omitted because neither section claimed it. {note}
−## The GFPE maximum setting shall not exceed 1200 A, and the maximum time delay shall not exceed one second for ground-fault currents of 3000 A or greater, per NEC 230.95(A).
+## Whether ground-fault protection of equipment is provided shall be as indicated in the datasheet.
−## A field performance test of the ground-fault protection system shall be performed when the equipment is first installed, per NEC 230.95(C), and the written results shall be submitted before energization. {note}
−
−## The 230.95(C) test is a code requirement, not optional commissioning. It verifies, by primary or secondary current injection with calibrated equipment, that the GFPE actually trips at the intended pickup and time delay. Treating it as discretionary commissioning is a code violation. {note}
−
```datasheet
label: GFPE provided
type: radio
options:
− - Required (480Y/277 V service, disconnect ≥ 1000 A)
− - Not required
−default: Not required
+ - Provided — required by NEC 230.95
+ - Provided — elected below the NEC 230.95 threshold
+ - Not provided — not required by NEC 230.95
```
+## Whether GFPE is mandatory follows from the service voltage and the disconnect rating, both of which are selected elsewhere in this datasheet; an owner may also elect GFPE below the code threshold. No answer is correct for every project, so the field carries no default. {note}
+
+## The GFPE maximum setting shall not exceed 1200 A, and the maximum time delay shall not exceed one second for ground-fault currents of 3000 A or greater, per NEC 230.95(A).
+
+## The GFPE pickup setting and time delay shall be as indicated in the datasheet and shall be coordinated with the project's protective device coordination study.
+
```datasheet
label: GFPE pickup setting
type: range
unit: A
−min: 100
−max: 1200
−step: 100
−default: 600
+drawing_ref: "protective device setting schedule"
+options:
+ min: 100
+ max: 1200
+ step: 100
+default: deferred
```
…2 unchanged lines
type: range
unit: s
−min: 0.1
−max: 1.0
−step: 0.1
−default: 0.2
+drawing_ref: "protective device setting schedule"
+options:
+ min: 0.1
+ max: 1.0
+ step: 0.1
+default: deferred
```
+## See [[sync/protective-coordination-study]] for the study that establishes these settings. {note}
+
+## A field performance test of the ground-fault protection system shall be performed when the equipment is first installed, per NEC 230.95(C), and the written results shall be submitted before energization.
+
+## The 230.95(C) test is a code requirement, not optional commissioning. It verifies, by primary or secondary current injection with calibrated equipment, that the GFPE actually trips at the intended pickup and time delay. Treating it as discretionary commissioning is a code violation. {note}
+
# Emergency Disconnect {toc}
−## For one- and two-family dwelling units, an emergency disconnect shall be installed in a readily accessible outdoor location per NEC 230.85. {note}
+## For one- and two-family dwelling units, an emergency disconnect shall be installed in a readily accessible outdoor location per NEC 230.85.
−## This is a 2023 NEC addition. It requires an outdoor disconnecting means even when the main service panel is indoors, so that first responders can de-energize a dwelling from outside. The emergency disconnect shall be marked per 230.85 to identify its function (service disconnect, meter disconnect, or emergency disconnect not service equipment). {note}
+## This is a 2023 NEC addition. It requires an outdoor disconnecting means even when the main service panel is indoors, so that first responders can de-energize a dwelling from outside. NEC 230.85 recognizes three arrangements, each with its own required marking: the service disconnect itself placed outdoors, a meter disconnect ahead of the service equipment, and a disconnect that is not service equipment. {note}
## The emergency disconnect shall be legibly marked with the wording required by NEC 230.85 to identify its type and function.
+## The emergency disconnect arrangement shall be as indicated in the datasheet.
+
```datasheet
label: Emergency disconnect (one- and two-family dwellings)
type: radio
options:
− - Provided (outdoor, readily accessible)
− - Not applicable (non-dwelling occupancy)
−default: Not applicable (non-dwelling occupancy)
+ - Provided — service disconnect at an outdoor readily accessible location
+ - Provided — meter disconnect ahead of the service equipment
+ - Provided — emergency disconnect, not service equipment
+ - Not applicable (occupancy other than one- and two-family dwelling)
```
+## The arrangement follows from the occupancy and from where the service equipment is placed, so the field carries no default. {note}
+
# Enclosures and Mounting {toc}
−## Service-equipment enclosures shall be securely mounted to a structural surface or a freestanding rack rated for the equipment weight and the seismic conditions of the site.
+## Service-equipment enclosures shall be securely mounted to a structural surface or a freestanding rack rated for the equipment weight and the seismic conditions of the site per ASCE 7.
−## Outdoor-mounted enclosures shall be NEMA 3R minimum and shall be installed with the required working clearances in front of the equipment maintained per NEC 110.26. {note}
+## Outdoor-mounted service-equipment enclosures shall be rated NEMA 3R minimum.
+## The working clearances of NEC 110.26 shall be maintained in front of all service equipment.
+
## Working-clearance violations — equipment crowded into an alcove, against a fence, or behind a door swing — are among the most common service-entrance rejections and are dangerous to maintain. The clearance depth, width, and headroom of NEC 110.26 must be reserved on the drawings, not discovered in the field. {note}
−## Service-entrance raceways and enclosures shall be bonded as required for service equipment; grounding electrode and bonding details are governed by [[sync/grounding-and-bonding]]. {note}
+## Service-entrance raceways and enclosures shall be bonded as required for service equipment.
+## Grounding electrode and bonding details are governed by [[sync/grounding-and-bonding]]. {note}
+
+## The enclosure mounting arrangement shall be as indicated in the datasheet.
+
```datasheet
label: Enclosure mounting
type: radio
+drawing_ref: "electrical riser diagram"
options:
- Surface-mounted on building wall
- Freestanding on rack or pad
- Recessed (flush) in wall
−default: Surface-mounted on building wall
+default: deferred
```
# Identification and Arc-Flash Labeling {toc}
−## Service equipment shall be field-marked with an arc-flash warning label and the available incident energy or required PPE category per NFPA 70E. {note}
+## Service equipment shall be field-marked with an arc-flash warning label and the available incident energy or required PPE category per NFPA 70E.
## The arc-flash label tells anyone opening the equipment what hazard they face and what PPE is required. At the service entrance the available fault current is at its highest, so the incident energy can be severe; the label is both a safety requirement and a maintenance prerequisite. {note}
…9 unchanged lines
## The service-entrance conductors shall be free of grounds and shorts.
−## Where GFPE is provided, the field performance test required by NEC 230.95(C) shall be completed and documented before the service is energized.
−
## Phase rotation shall be verified on three-phase services before connecting downstream equipment.
+## The pre-energization tests to be performed shall be as indicated in the datasheet.
+
```datasheet
label: Pre-energization tests required
…14 unchanged lines
## The service entrance shall be installed in accordance with the approved shop drawings, the manufacturer's installation instructions, NEC Article 230, and the serving utility's requirements.
−## Service-entrance conductors shall be continuous without splice from the point of delivery to the service disconnect except where splices are specifically permitted by NEC 230.46. {note}
+## Service-entrance conductors shall be continuous without splice from the point of delivery to the service disconnect except where splices are specifically permitted by NEC 230.46.
−## The length of service-entrance conductors inside the building ahead of the service disconnect shall be kept to the minimum practicable. {note}
+## The length of service-entrance conductors inside the building ahead of the service disconnect shall be kept to the minimum practicable.
## Conductors ahead of the service disconnect are not protected by the service overcurrent device, so every additional foot inside the building is unprotected and increases the fire exposure of an unfused fault. The code intent of "nearest the point of entrance" is to make this length as short as the construction allows. {note}
−## Underground raceways entering the building shall be sealed per NEC 230.8 after conductors are installed.
+## Underground raceways entering the building shall be sealed against the entry of moisture, gases, and vermin per NEC 230.8 after conductors are installed.
−## Equipment shall be installed plumb, level, and with all manufacturer-required working clearances maintained.
+## Equipment shall be installed plumb and level.
## Field-installed service-equipment labels and arc-flash labels shall be applied before the equipment is placed in service.
…9 unchanged lines
# Warranty {toc}
−## The manufacturer shall warrant the service equipment against defects in materials and workmanship for not less than one year from the date of energization or substantial completion, whichever is later.
+## The manufacturer shall warrant the service equipment against defects in materials and workmanship for the period indicated in the datasheet, and in no case less than one year from the date of energization or substantial completion, whichever is later.
```datasheet
label: Warranty period
−type: select
+type: range
unit: years
options:
− - "1"
− - "2"
− - "5"
−default: "1"
+ min: 1
+ max: 5
+ setpoints: [1, 2, 5]
+default: 1
```
…2 unchanged lines
## The Contractor shall furnish spare fuses of each type and rating installed in fusible service equipment, in the quantity required by the project specifications.
−## For services with field-replaceable trip units or control power components, the Contractor shall furnish the manufacturer's recommended spare-parts list for owner stock. {note}
+## For services with field-replaceable trip units or control power components, the Contractor shall furnish the manufacturer's recommended spare-parts list for owner stock.
+## The spare parts to be furnished shall be as indicated in the datasheet.
+
```datasheet
label: Spare parts to be furnished
…5 unchanged lines
default:
- Spare fuses (each type and rating, fusible switches)
+ - Manufacturer recommended spares list
```