Fuse size question

[juicegoose]

So I just got my 24000btu pioneer 220 volt system. I see it says min wire amps is 15 and max breaker size is 25 amps. So min wire size is a #14 but obviously if I put a 25 amp breaker on that the wire would go up. I already have a 20 amp 220v circuit I ran years ago for woodworking. Yes it’s 20 amp 220 and #12 wire.

Does the unit pull 25 amps or would I be good reusing the 20amp 220v feed I already have in the panel

 

[brewchief]

You can safely and legally wire it with #14 wire and a 25 amp breaker, there is an exception in the code that allows it.

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[Milton Shaw]

Try what you have and if it blows breaker, get the 25 amp. But it will probably work OK the way it is...

 

[6768rogues]

You can safely and legally wire it with #14 wire and a 25 amp breaker, there is an exception in the code that allows it.

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I wasn't aware of that. Do you know the logic behind the exception?

 

[TRWham]

I wasn't aware of that. Do you know the logic behind the exception?

Electric motors can draw very large current briefly when starting, and HVAC units have the largest motors you'll see in most homes (big *** air compressors being an exception). These units will be internally protected against sustained overload, so the NEC allows larger breakers on the branch circuits that power them to allow the starting current to pass without nuisance trips, while that internal protection prevents overload that might damage the conductors. Article 440 in the NEC covers wiring requirements for HVAC units.

 

[justinjoyal]

You’ll be fine with your existing circuit.

 

[MFolks]

The inrush current is many times greater than usually the continual load one is.