NEC 440.22(C)

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don_resqcapt19

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That is a good question. Is heating "air conditioning"?
440.1 Scope. The provisions of this article apply to electric motor-driven air-conditioning and refrigerating equipment and to the branch circuits and controllers for such equipment. It provides for the special considerations necessary for circuits supplying hermetic
refrigerant motor-compressors and for any air-conditioning or refrigerating equipment that is supplied from a branch circuit that supplies a hermetic refrigerant motor-compressor.

I believe that the intent is that "air-conditioning" as used in this section is cooling and not heating.

The NEC Handbook says, "Article 440 does not apply unless a hermetic refrigerant motor-compressor is supplied. Article 440 must be applied in conjunction with Article 430." I don't think that the handbook commentary is correct, as it is my opinion that Article 440 applies to alll types of refrigeration equipment, not just equipment that has a hermetic compressor.
 

kwired

Electron manager
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NE Nebraska
440.1 Scope.


The provisions of this article apply to electric motor-driven air-conditioning and refrigerating equipment and to the branch circuits and controllers for such equipment. It provides for the special considerations necessary for circuits supplying hermetic refrigerant motor-compressors and for any air-conditioning or refrigerating equipment that is supplied from a branch circuit that supplies a hermetic refrigerant motor-compressor.
Though it doesn't quite say it is limited to equipment using hermetic refrigerant compressors - it seems to indicate that is one of the more important characteristics that art 440 is about. One may have to go a long way back to see ROP's that indicate what the intention may be here.
 

Henley

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I would say it only applies to Hermetic, which I assume the Fan Blower is NOT.
Look at article 430.52 (C) 2, It basically says the same thing as 440.22 C, but the limits are based on
Table 430.52 which are Higher than Hermetic allowed increases of 175%/225%.
So for the Fan Blower of AC or Heat, I use 430.52.
 

kwired

Electron manager
Location
NE Nebraska
I would say it only applies to Hermetic, which I assume the Fan Blower is NOT.
Look at article 430.52 (C) 2, It basically says the same thing as 440.22 C, but the limits are based on
Table 430.52 which are Higher than Hermetic allowed increases of 175%/225%.
So for the Fan Blower of AC or Heat, I use 430.52.
Actually for a fan coil unit you start out in art 422 - though it may send you to art 430 for some things or even 440 if there is a hermetic compressor involved.
 

Henley

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Location
Chesapeake Bay
Actually for a fan coil unit you start out in art 422 - though it may send you to art 430 for some things or even 440 if there is a hermetic compressor involved.

Yes you are absolutely right. But since the OP referred to an article about the "Rating" of a motor circuit I didn't want to
confuse things by sending the OP through 422 to get to 432.52, sometimes the NEC is confusing enough on it's own.:D
 
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