What is the maximum ampacity of #6 THHN copper wire?
Question:I've seen ratings from 40 amps up to 100 amps. The wiring is going to be in PVC conduit. I'm having a new air handler installed and I'm responsible for the wiring up to the disconnect. The Air Handler is going to be fed by a 240VAC 60 amp circuit.
Answers:
I would go by what is printed on the wire as this is from the AWG officials !
hi
65 amps * 80% = 52 amps
Titus - #6 copper is rated at 100 amps free air and 60 amps in enclosed conduit. It must be one monster air handler, I've never heard of an air handler using more than a 30 amp circuit in a residence.
Electrical Code book table 310.16
#6 thhn rated at 75 amp 75X 80% is a 60A breaker
if it is in a romex bundle NM wire with the bare ground like stove wire it needs to be on a 50A breaker because of the rating of the bare wire.
use a # 10 insulated ground in the conduit also
If its a romex bundle it shouldn't be run in a PVC conduit you should use thhn for that application. If that's the only wire in that conduit it's good for 60 amps unless the distance is so great you have to consider voltage drop, but that would require more details.
Inspector scoot over a little your reading the wrong column!
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