Electrical breaker of A/C in the electrical panel


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Old 05-10-19, 12:06 PM
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Electrical breaker of A/C in the electrical panel

Please see the pic in the below link. I'm sure 30 on the top of poles mean 30 amp, but why do I have two interconnected breakers for A.C. unit when I only have one A.C. unit in my home? Both poles on each of the interconnected breakers say 30. Is the total am of the breakers 30 amp instead of 30 + 30 = 60 amp? Thank you for your help.

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Last edited by PJmax; 05-10-19 at 04:39 PM. Reason: imported picture
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Old 05-10-19, 12:11 PM
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The AC is 240V so it is a double pole breaker to provide 240V. It is only 30A at 240V.
 
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Old 06-07-19, 08:08 AM
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The inspector said 30 amp MAX breaker is required. So does it mean if I have 30 amp breaker as shown in the pic, the amperage is 30 amp at MAX and it could be lower than 30 amp based on the load on my AC unit?
 
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Old 06-07-19, 08:36 AM
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The AC unit may specify max size as 30 Amp, not sure what the issue is.
Geo
 
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Old 06-07-19, 10:24 AM
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AC units typically allow the installer to select from a range of breaker sizes based on the specifics of the installation. As long as the unit is operating normally, there is no problem using the largest allowed breaker within the range. The outdoor unit will have a label with electrical specs on it; MCA is the smallest allowed breaker; Max OCPD/breaker/fuse is the largest allowed.
 
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Old 06-12-19, 08:15 AM
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MCA is the smallest allowed breaker; Max OCPD/breaker/fuse is the largest allowed.

Actually, MCA means Minimum Circuit Ampacity. An MCA of 28 amps means the circuit must be rated at minimum for 28 amps. The next largest circuit would be 30 amps so #10 wire would be used for the circuit. With a MCA of 28, I would expect the MOCP to be at least 35 amps, but more likely to be 40 amps.
 
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