1.5 ton central air unit


Old 09-30-09, 01:13 PM
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Cool 1.5 ton central air unit

i am having a YORK 1.5 ton central air conditioner installed in a week and the fellow who is doing the work says all he wants me to do is put in a 20 amp circuit(12/2)....does this sound right to you guys or should i go larger...say 30 or 40 amp?
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Old 09-30-09, 02:01 PM
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We are talking of course about a 240 volt circuit, and a 1 ton unit from any brand I looked at would require a circuit breaker of 20 amps max, maybe even 15.
Old 09-30-09, 02:08 PM
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The circuit should be based on the electrical requirements of the A/C unit. Specifically the "minimum circuit ampacity" to determine the cable size and the "maximum overcurrent protection (OCPD)" to determine the breaker size. Sometimes the "max fuse" is also specified by the manufacturer which would require a fused disconnect.

A 20A breaker with 12/2 cable sounds about right for a 1.5T A/C, but you need to know the manufacturer specs to be sure.
Old 09-30-09, 02:34 PM
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All the 1 1/2 ton units I install have a manufacturer maximum recommended breaker size of 15 amps.
Our code would permit a 20 amp breaker to be installed but by using a 15 amp breaker it would prevent the compressor overload from tripping if the thermostat were cycled too quickly.
The breaker would trip instead giving you better compressor protection IMO.

I would suggest you use 12 g wire and a 15 amp breaker if the mfr and codes permit it.
Old 09-30-09, 05:23 PM
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I done few hook up with 1.5 tonne airconding units and they useally don't require more than 15 amp circuit in most case but few did speced 20 amp however with 12-2 you are fine with it.

But due the techolgly change they are getting more effeiect with the unit so double check the nameplate on the unit to verify the latest details.


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