Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
---
title: Utility Manholes and Handholes
category: Electrical
toc_depth: 3
description: >
− When to use: Selecting and specifying below-grade access structures for underground electrical and low-voltage systems -- precast concrete manholes (personnel-entry), precast concrete handholes/vaults, and polymer-concrete or composite handholes serving medium-voltage feeders, low-voltage distribution, lighting circuits, and communications/data ductbanks. Covers ductbank pull points, cable splice and termination locations, inspection access, cover and frame assemblies, load/tier ratings, cover markings, sumps and drainage, grounding/bonding attachments, pulling irons, and cable rack inserts.
+ When to use: Selecting and specifying below-grade access structures for underground electrical and low-voltage systems — precast concrete manholes (personnel-entry), precast concrete handholes/vaults, and polymer-concrete or composite handholes serving medium-voltage feeders, low-voltage distribution, lighting circuits, and communications/data ductbanks. Covers ductbank pull points, cable splice and termination locations, inspection access, cover and frame assemblies, load/tier ratings, cover markings, sumps and drainage, grounding/bonding attachments, pulling irons, and cable rack inserts.
Not intended for: Underground conduit/ductbank routing, trench design, and concrete encasement (see [[sync/underground-ductbank]]); conduit and raceway material, fittings, and methods (see [[sync/raceways-and-conduit]]); conductors, cables, splices, and cable tray (see [[sync/conductors-and-cables]]); broader storm/sanitary/water/gas main coordination (see [[sync/site-utilities]]); above-grade pull, junction, and outlet boxes; AASHTO bridge-loaded roadway manholes; and wet-well or sump-pump drainage structures.
---
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## The following are outside the scope of this standard. {note}
−- Underground conduit and ductbank routing, trench design, and concrete encasement -- see [[sync/underground-ductbank]].
−- Conduit and raceway material selection, fittings, and installation methods -- see [[sync/raceways-and-conduit]].
−- Conductors, cables, splicing methods and materials, and cable tray -- see [[sync/conductors-and-cables]].
−- Broader site utility coordination for storm, sanitary, water, and gas mains -- see [[sync/site-utilities]].
+- Underground conduit and ductbank routing, trench design, and concrete encasement — see [[sync/underground-ductbank]].
+- Conduit and raceway material selection, fittings, and installation methods — see [[sync/raceways-and-conduit]].
+- Conductors, cables, splicing methods and materials, and cable tray — see [[sync/conductors-and-cables]].
+- Broader site utility coordination for storm, sanitary, water, and gas mains — see [[sync/site-utilities]].
- Above-grade pull boxes, junction boxes, and outlet boxes mounted on walls or in ceilings, which are governed by NEC Article 314 but are not the subject of this standard.
- Traffic-signal or roadway manholes with structural bridge-loading requirements beyond H-20, which fall under AASHTO/civil scope.
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## The structural designer of each personnel-entry manhole shall be a professional engineer licensed in the jurisdiction of the project.
−## A single manufacturer shall furnish each structure complete with its matching cover and frame assembly so that load ratings are coordinated as a system. {note}
+## A single manufacturer shall furnish each structure complete with its matching cover and frame assembly so that load ratings are coordinated as a system.
## Mixing a third-party cover or frame onto a structure body can defeat the certified tier rating, because the rating is established for the body and lid as a tested assembly. Furnishing matched components from one source preserves the certified rating and assigns single-source responsibility for fit and performance. {note}
## Personnel-entry manholes are permit-required confined spaces and shall comply with OSHA 29 CFR 1910.146.
−## Confined-space provisions -- ventilation access, fixed or portable ladder access, and rescue retrieval -- shall be coordinated among the electrical, structural, and safety disciplines and reflected in the structure design.
+## Confined-space provisions — ventilation access, fixed or portable ladder access, and rescue retrieval — shall be coordinated among the electrical, structural, and safety disciplines and reflected in the structure design.
# Environmental and Service Conditions {toc}
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```
−# Sizing {toc}
+# A box sized by catalog convenience rather than by the cables it must serve generates RFIs at cable installation, when the installer discovers the bend radius or fill cannot be achieved.
−## A box sized by catalog convenience rather than by the cables it must serve generates RFIs at cable installation, when the installer discovers the bend radius or fill cannot be achieved. {note}
+# NEC Article 314 establishes minimum dimensions for pull and junction boxes and handhole enclosures based on the largest raceway entering and the conductor bend radius, not on round-number catalog sizes. The plan dimensions and depth must be verified against the actual cable schedule for the largest conductors that will be pulled, with a service factor for future pulls, before a structure size is committed. {note}
−## NEC Article 314 establishes minimum dimensions for pull and junction boxes and handhole enclosures based on the largest raceway entering and the conductor bend radius, not on round-number catalog sizes. The plan dimensions and depth must be verified against the actual cable schedule for the largest conductors that will be pulled, with a service factor for future pulls, before a structure size is committed. {note}
+# Plan dimensions and depth shall satisfy the minimum sizing required by NEC Article 314 for the largest raceway and conductor entering the structure.
−## Plan dimensions and depth shall satisfy the minimum sizing required by NEC Article 314 for the largest raceway and conductor entering the structure.
+# Structure dimensions shall be verified against the project cable schedule for conductor bend radius and fill before a size is committed.
−## Structure dimensions shall be verified against the project cable schedule for conductor bend radius and fill before a size is committed.
+# Each structure shall include a service factor of spare interior space for future cable pulls.
−## Each structure shall include a service factor of spare interior space for future cable pulls.
+# The number, size, and location of duct entries (knockouts or cast-in terminators) shall be coordinated with the ductbank design per [[sync/underground-ductbank]] and shown on the shop drawings.
−## The number, size, and location of duct entries (knockouts or cast-in terminators) shall be coordinated with the ductbank design per [[sync/underground-ductbank]] and shown on the shop drawings.
−
```datasheet
label: Spare Capacity / Service Factor for Future Pulls
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## Cover Markings {toc}
−### NEC 314.30 requires that a handhole cover be marked to identify it, but it does not specify the legend text -- the owner standard must define it, or the contractor will install blank or wrong-discipline covers. {note}
+### NEC 314.30 requires that a handhole cover be marked to identify it, but it does not specify the legend text — the owner standard must define it, or the contractor will install blank or wrong-discipline covers. {note}
### A cover that reads ELECTRIC over a telecommunications structure, or carries no legend at all, invites a wrong-discipline excavation and is a safety and maintenance liability. The discipline legend, and any owner asset-numbering provision, must be specified explicitly rather than left to the installer. {note}
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# Drainage and Sump {toc}
−## A structure built without a deliberate water-management decision will either fill with water (if sealed in a high water table) or flood from surface inflow (if unsealed in a low-lying area); the specification must state which approach applies. {note}
+## A structure built without a deliberate water-management decision will either fill with water (if sealed in a high water table) or flood from surface inflow (if unsealed in a low-lying area); the specification must state which approach applies.
## There is no universally correct drainage scheme. Where the water table is below the structure floor and a daylight or storm connection is available, a gravity drain is simplest. Where no gravity outlet exists, a perforated sump pit in the floor lets water percolate into the soil. Where the structure must remain dry or the authority prohibits discharge, a sealed watertight structure is required and water is removed by maintenance pumping. The choice depends on the water table and the local authority, and it must be coordinated with [[sync/site-utilities]]. {note}
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## Sealed watertight structures shall use gasketed or mastic-sealed joints and sealed duct entries to exclude groundwater.
−## Ductbank invert elevations shall be coordinated so that conduits drain toward the structure and do not trap water, per [[sync/underground-ductbank]]. {note}
+## Ductbank invert elevations shall be coordinated so that conduits drain toward the structure and do not trap water, per [[sync/underground-ductbank]].
## Many owners require ductbanks to slope toward manholes at a minimum of 1/8 in. per ft so that water drains out of the conduit and into the structure. If the manhole invert is set level with the incoming conduit, gravity drainage fails and water is trapped in the duct, which can freeze and damage cable. The structure invert must be set below the incoming conduit inverts so the slope is real. {note}
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# Grade Adjustment {toc}
−## Final cover elevation must match finished grade, and if the design does not specify adjustable grade rings the contractor field-improvises and the cover ends up proud of or below the pavement. {note}
+## Final cover elevation must match finished grade, and if the design does not specify adjustable grade rings the contractor field-improvises and the cover ends up proud of or below the pavement.
## The top of the structure is set during installation but the finished grade is established later by paving or landscaping. Concrete adjustment rings or HDPE/cast-iron grade rings let the installer bring the frame and cover to the exact final elevation. The allowable range of adjustment and the ring material must be specified so the contractor does not improvise with shims or excess mortar. {note}
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## Placing power and telecommunications cable in the same structure without segregation violates utility owner rules and the spirit of NEC 300.3, and it must be resolved at design, not in the field. {note}
−## Where a single structure must carry both power and communications cable, the two systems must be physically segregated -- typically on cable racks on opposite walls with a minimum clearance between them -- so that induced voltage, heat, and maintenance access do not create a conflict. Many utility owners flatly prohibit shared structures; where they are permitted, the segregation arrangement must be shown on the shop drawings. {note}
+## Where a single structure must carry both power and communications cable, the two systems must be physically segregated — typically on cable racks on opposite walls with a minimum clearance between them — so that induced voltage, heat, and maintenance access do not create a conflict. Many utility owners flatly prohibit shared structures; where they are permitted, the segregation arrangement must be shown on the shop drawings. {note}
## Power and communications cable shall not share a structure unless the design explicitly provides for it and the serving utility permits it.
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default: 2
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