Plastic Wireway Conductor Fill

[edavis2293]

The NEC still states the minimum size conductor for power circuits is No. 14. However, NFPA 79 states the minimum size power circuit in plastic wireway is No. 18. The ampacity of No. 16 is 10 amps and 8 amps for No. 18. What is the conductor fill of these raceways in control panels and do we need any derating based on the number of conductors? It is not unusual to have 100 conductors at a cross section. No. 16 power and control conductors are mixed in the ducts.

 

[petersonra]

Re: Plastic Wireway Conductor Fill

NEC rules do not apply inside a control panel covered by NFPA79.

[ July 07, 2005, 09:33 AM: Message edited by: petersonra ]