NFPA Wire Reference

[Bob NH]

I have a project where the customer is using AWG 6 Machine Tool Wire (MTW) Style 1283 rated at 105 C for a solar energy system, and there is a need to run alternating current from the inverter to the load center. The wire is also rated as CSA TEW.

NEC 2005 310.15(A)(1) FPN No. 2 refers to Table 13.5.1 of NFPA 79-2002, which I don't have and don't otherwise have occasion to use.

Does anyone have a reference which would give the ampacity for the AWG 6 MTW Style 1283 wire rated at 105 C, when used in a raceway in a dry location with not more than 3 wires?

I assume that the 75 C ampacity would apply unless there is something else in NFPA 79 that prohibits it.

 

[RUWired]

NFPA 79 lists #6 mtw; 55amps/60degree 65amps/75degree.You can visit nfpa online via this site.
Rick

 

[W6SJK]

Are you sure that the plan reviewer will allow use of MTW for this application, i.e. building wiring to the loadcenter?

Sidebar: Don't forget that the loadcenter bus must be equal to or greater than the sum of the incoming feeder overcurrent protection plus the CB size of the backfeed from the inverter. That gets missed occasionally and is very important.

 

[Bob NH]

The load center/distribution is all in the same building and there is no external power. This is a remote site with only solar power, and an auxiliary generator that is used to supplement the charge on the batteries when the solar can't handle the load.

The wiring goes from batteries to the inverter/charger/control unit, and then from the that unit to a single phase load center nearby.