Heat pump whip

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iwire said:
I am out.:D

This is all well established, it is blowing my mind you are not seeing it.
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OK, I'll jump in.

luckylerado said:
I am sorry but where does either E or G specifically permit this?
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240.4(G) specifically allows "small conductors" supplying air conditioning equipment to be protected per Art 440. Per Art. 440, the equipment in the OP requires a conductor with an ampacity of at least 22 and allows the conductors to be protected at not greater than 35A.
 
I hope the NM-B is not actually running outside, even in a raceway. Some AHJs may not even accept the transition from NM to whip being in an outside box.
 
luckylerado said:
Agreed. Which table does 440 say to use? 440 allows you to upsize the OCP not downsize the required ampacity.
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david luchini said:
And #12 THHN or THWN has an allowable ampacity of 25 at 75degC...which is greater than 22.
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I agree and that's the key, the ampacity of #12 THWN in the whip can be sized at 75° C which is 25 amps. The 20 amp limitation of 240.4(D) does not apply.
 
I think that I see my error. In my mind I am looking for something specific like:

"The provisions of 240.4(D) shall not apply"

but I see now that it is unnecessary and that the ** in 310.15(B)(16) do not modify the ampacity.

Maybe the equipment is marked 60° :p
 
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