Raceways and Conduit
Corpus sync: neutrality remakes, note hygiene, datasheet relocation, transformer-split cross-refs
Showing changes from Rev 3
to Rev 4
in Raceways and Conduit.
---
title: Raceways and Conduit
…175 unchanged lines
### In corrosive environments — coastal exposure, chemical processing areas, wastewater facilities, swimming pool equipment rooms, and similar — the Contractor shall provide raceway with corrosion resistance suitable for the specific exposure.
−### Options include PVC-coated rigid metal conduit conforming to NEMA RN 1, aluminum RMC, stainless steel RMC, or nonmetallic raceway. {note}
```datasheet
…19 unchanged lines
default: "PVC-coated rigid metal conduit (NEMA RN 1)"
```
+### Options include PVC-coated rigid metal conduit conforming to NEMA RN 1, aluminum RMC, stainless steel RMC, or nonmetallic raceway. {note}
### Per NEC 300.6, metal raceway and supports shall be protected against corrosion.
…72 unchanged lines
### Use RMC where conductors require maximum physical protection, at building entrances, in exposed exterior risers, and where the conduit is subject to severe physical damage. {note}
+### Rigid metal conduit shall comply with UL 6 (steel) or UL 6A (aluminum, red brass, stainless steel) and, for steel RMC, the dimensional requirements of ANSI C80.1, and shall be installed per NEC Article 344.
+
```datasheet
label: Rigid Metal Conduit Material
…7 unchanged lines
```
−### Rigid metal conduit shall comply with UL 6 (steel) or UL 6A (aluminum, red brass, stainless steel) and, for steel RMC, the dimensional requirements of ANSI C80.1, and shall be installed per NEC Article 344.
−
### Steel RMC shall be hot-dip galvanized inside and out.
…81 unchanged lines
### PVC conduit also expands and contracts significantly with temperature change, which is addressed by the expansion-fitting requirements of this standard. {note}
+### Rigid polyvinyl chloride conduit shall comply with UL 651 and NEMA TC 2, fittings shall comply with NEMA TC 3, and the system shall be installed per NEC Article 352.
+
+### Schedule 80 PVC has a thicker wall and shall be used where the conduit is exposed to physical damage, including at above-grade transitions from underground routing.
+
```datasheet
label: Rigid PVC Conduit Wall Schedule
…5 unchanged lines
```
−### Rigid polyvinyl chloride conduit shall comply with UL 651 and NEMA TC 2, fittings shall comply with NEMA TC 3, and the system shall be installed per NEC Article 352.
−
−### Schedule 80 PVC has a thicker wall and shall be used where the conduit is exposed to physical damage, including at above-grade transitions from underground routing.
−
### PVC conduit exposed to sunlight shall be listed and marked sunlight resistant.
…30 unchanged lines
### Wireway is a sheet-metal or nonmetallic trough with a hinged or removable cover, used to consolidate and route large numbers of conductors between distribution equipment, in equipment rooms, and at gutter connections to panelboards. {note}
+### Metal wireway and nonmetallic wireway shall comply with UL 870 and be installed per NEC Article 376 (metal) or 378 (nonmetallic).
+
```datasheet
label: Wireway Type and Rating
…8 unchanged lines
```
−### Metal wireway and nonmetallic wireway shall comply with UL 870 and be installed per NEC Article 376 (metal) or 378 (nonmetallic).
−
### Per NEC 376.22, the sum of the cross-sectional areas of all contained conductors shall not exceed 20 percent of the interior cross-sectional area of a metal wireway.
…7 unchanged lines
## Bonding requirements are coordinated with [[sync/grounding-and-bonding]]. {note}
+## Fittings, connectors, and couplings shall comply with UL 514B and NEMA FB 1 and shall be of a type listed for the raceway with which they are used and for the location and environment of the installation.
+
+## Connectors at boxes and enclosures shall maintain the mechanical integrity and, for metal raceway systems, the electrical continuity of the equipment grounding path.
+
+## Insulating bushings or insulated throat connectors shall be provided where conductors enter a raceway termination.
+
+## Bushings shall be installed on all raceway terminations carrying conductors 4 AWG and larger.
+
+## Bonding-type fittings or bonding bushings shall be provided where required to maintain the equipment grounding path.
+
```datasheet
label: Metal Conduit Connector Type
…7 unchanged lines
```
−## Fittings, connectors, and couplings shall comply with UL 514B and NEMA FB 1 and shall be of a type listed for the raceway with which they are used and for the location and environment of the installation.
−
−## Connectors at boxes and enclosures shall maintain the mechanical integrity and, for metal raceway systems, the electrical continuity of the equipment grounding path.
−
−## Insulating bushings or insulated throat connectors shall be provided where conductors enter a raceway termination.
−
−## Bushings shall be installed on all raceway terminations carrying conductors 4 AWG and larger.
−
−## Bonding-type fittings or bonding bushings shall be provided where required to maintain the equipment grounding path.
−
## The Contractor shall provide bonding bushings at service equipment and at all terminations where standard locknut connections do not establish a reliable ground-fault current path.
…40 unchanged lines
## Although NEC permits 1/2 in. raceway for many branch circuits, a 3/4 in. minimum is recommended for homerun and feeder raceway and for any raceway that may be extended in the future, because the marginal cost is small and the additional capacity reduces fill conflicts.
−## Spare raceways stubbed from flush-mounted panelboards to an accessible ceiling space allow future circuits to be added without opening finished walls. {note}
```datasheet
…8 unchanged lines
default: "3/4"
```
+## Spare raceways stubbed from flush-mounted panelboards to an accessible ceiling space allow future circuits to be added without opening finished walls. {note}
−```datasheet
−label: Spare Raceway Capacity for Future Use
−type: radio
−options:
− - "No spare raceways required"
− - "Provide spare raceways from each flush panelboard to accessible ceiling"
− - "Provide spare raceways as indicated on drawings"
−default: "Provide spare raceways from each flush panelboard to accessible ceiling"
−```
−
## Raceway fill shall not exceed the limits of NEC Chapter 9, Table 1.
…10 unchanged lines
## Where spare raceways are provided, the Contractor shall install a pull string and cap each end, with quantity and routing [[drawing: as indicated on the panelboard schedules and electrical plans]].
+```datasheet
+label: Spare Raceway Capacity for Future Use
+type: radio
+options:
+ - "No spare raceways required"
+ - "Provide spare raceways from each flush panelboard to accessible ceiling"
+ - "Provide spare raceways as indicated on drawings"
+default: "Provide spare raceways from each flush panelboard to accessible ceiling"
+```
+
# Supports and Fasteners {toc}
…44 unchanged lines
## Per NEC 300.7(B), raceway shall be provided with expansion fittings, expansion-deflection fittings, or deflection fittings where necessary to compensate for thermal expansion and contraction and for structural movement.
−## Rigid PVC conduit has a coefficient of thermal expansion roughly five times that of steel, and long exposed exterior PVC runs and PVC risers are the most common locations where expansion fittings are omitted in error, resulting in pulled joints and broken conduit. {note}
```datasheet
…7 unchanged lines
default: "At all building expansion and seismic joints"
```
+## Rigid PVC conduit has a coefficient of thermal expansion roughly five times that of steel, and long exposed exterior PVC runs and PVC risers are the most common locations where expansion fittings are omitted in error, resulting in pulled joints and broken conduit. {note}
## Expansion fittings shall be provided where raceway crosses a building expansion, seismic, or settlement joint, located [[drawing: as indicated on the structural and architectural drawings]].
…12 unchanged lines
## Metallic raceway systems and the equipment grounding path within them shall be electrically continuous and shall be bonded to provide an effective ground-fault current path per NEC 250.4 and NEC Article 250, Part V. Listed RMC, IMC, and EMT with listed fittings are recognized equipment grounding conductors per NEC 250.118; nonmetallic raceways (rigid PVC, ENT, RTRC, HDPE, LFNC) provide no metallic path and require a separate equipment grounding conductor.
−## The selected grounding method is coordinated with [[sync/grounding-and-bonding]]. {note}
```datasheet
…5 unchanged lines
default: "Separate equipment grounding conductor in all raceways"
```
+## The selected grounding method is coordinated with [[sync/grounding-and-bonding]]. {note}
## Installing a separate equipment grounding conductor in all raceways — including metallic raceway that would otherwise qualify on its own — provides a low-impedance, redundant ground-fault path that does not depend on the long-term integrity of every threaded and mechanical raceway joint, and is preferred for feeders, for circuits serving sensitive equipment, and where the project requires the highest reliability. {note}
…150 unchanged lines
default: "1 year from substantial completion"
```