Mini split disconnect requirements

N

nizak

Senior Member
Does the indoor air handler of a mini split system require a separate disconnect or does the exterior compressor disconnect suffice?

Thank you
 
I dont think there is a clear answer. I would say that nothing in article 440 applies because the indoor unit does not have a hermetic compressor. If 430 applies i think that would be a within sight disconnect. If its an appliance, then its probably small enough that a remote disconnect is acceptable.
 
I think the answer lies in 440.8: "An air-conditioning or refrigerating system shall be considered to be a single machine under the provisions of 430.87, Exception No. 1, and 430.112, Exception. The motors shall be permitted to be located remotely from each other."

So the indoor unit and the outdoor unit are a single machine, and it's fine that the indoor unit has a motor in it remote from the outdoor unit. Then 430.112 Exception (1) allows a single disconnect for the entire machine.

Cheers, Wayne
 
wwhitney said:
I think the answer lies in 440.8: "An air-conditioning or refrigerating system shall be considered to be a single machine under the provisions of 430.87, Exception No. 1, and 430.112, Exception. The motors shall be permitted to be located remotely from each other."

So the indoor unit and the outdoor unit are a single machine, and it's fine that the indoor unit has a motor in it remote from the outdoor unit. Then 430.112 Exception (1) allows a single disconnect for the entire machine.

Cheers, Wayne
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Thank you.
 
Power will be off to the indoor unit when the outdoor unit is shut down. Also never have anything else on that circuit. Some folks have been temped to "add an outlet" when running this circuit. Bad idea. Some manufactures use a communication loop on the neutral and anything else added on will mess with that.
 
@herding_cats ive seen this before. Went on a call where someone thought the comm or white wire was a neutral. And somehow they tied it into another box with power circuits. I found out they had tied it to neutral. Whenever the unit would call for heat or cooling and the in door unit came on it would trip the breaker.
 
wwhitney said:
So the indoor unit and the outdoor unit are a single machine, and it's fine that the indoor unit has a motor in it remote from the outdoor unit. Then 430.112 Exception (1) allows a single disconnect for the entire machine.
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What if the indoor unit's fan was run from a completely separate circuit, rather than powered from the outside unit?
 
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