Article 378 Nonmetallic Wireways
Nonmetallic Wireways. Flame-retardant, nonmetallic troughs with removable covers for housing and protecting electrical wires and cables in which conductors are laid in place after the raceway has been installed as a complete system.
- Only for exposed work, except as permitted in 378.10 (4).
- Where subject to corrosive environments where identified for the use.
- In wet locations where listed for the purpose.
Informational Note: Extreme cold may cause nonmetallic wire-ways to become brittle and therefore more susceptible to damage from physical contact.
- As extensions to pass transversely through walls if the length passing through the wall is unbroken. Access to the conductors shall be maintained on both sides of the wall.
- Where subject to physical damage
- In any hazardous (classified) location, except as permitted by other articles in this Code
- Where exposed to sunlight unless listed and marked as suitable for the purpose
- Where subject to ambient temperatures other than those for which nonmetallic wireway is listed
- For conductors whose insulation temperature limitations would exceed those for which the nonmetallic wireway is listed
The adjustment factors specified in 310.15(C)(1) shall be applicable to the current-carrying conductors up to and including the 20 percent fill specified in the first paragraph of this section.
Informational Note: See Table 352.44 for expansion characteristics of PVC conduit. The expansion characteristics of PVC nonmetallic wireway are identical.