heater wire size

[bpk]

I have a job coming up that consists of wiring a 12kw floor heat boiler. The only specs from the manufacturer are to use a 70 amp breaker and copper conductors only. It is in a newer house where the ceilings are not yet finished and it is located 40 feet from the panel. My question is do they make a nm cable this large (#4 awg) or will I have to pipe it. Thanks in advance.

[walkerj]

Yes they make cable #4 and larger

[480sparky]

You can use ser cable (the gray stuff).

I'd submit an RFI for more information.

[Dennis Alwon]

I have a job coming up that consists of wiring a 12kw floor heat boiler. The only specs from the manufacturer are to use a 70 amp breaker and copper conductors only. It is in a newer house where the ceilings are not yet finished and it is located 40 feet from the panel. My question is do they make a nm cable this large (#4 awg) or will I have to pipe it. Thanks in advance.

Yes they make NM up to #2 copper in NM but they also make ser copper larger than that.

[iwire]

I suggest running aluminum SE or SER.

[walkerj]

I suggest running aluminum SE or SER.

I like the way you think!:D

[Dennis Alwon]

I suggest running aluminum SE or SER.
Even if the spec require copper? Never mind you are probably talking about the feeder not the wire to the heater.

[iwire]

Even if the spec require copper?

Well yes, you know me, ignore the rules and save a dime. :grin:

Almost everything I install has dual rated lugs, if I was in a pinch I could install pin adapters on the aluminum to deal with a copper only termination.