Hvac Circuit Breaker Sizing

Rounded up to 50a.

Hvac circuit breaker sizing.

An example of a circuit that is un intentionally open is when a circuit breaker operates due to too much current on the circuit and shuts the circuit off. The 80 of a 30a circuit breaker is 24a. But it doesn t matter. Ocpd 100 noncontinuous load 125 continuous load 1 00 x 30a 1 25 x 16a 50a.

This way a 30a circuit can be safely used for 24a circuit. The standard trip setting of a thermal magnetic breaker just smaller than this opd would be a 40 amp breaker. This gives you the amount of amps you need your circuit breaker to resist. Recalling that our conductor size was 12 with a maximum rating of 25 amps per table 310 16 we now have a 40 amp breaker protecting a conductor rated at 25 amps.

I mentioned that the minimum wire size for this air conditioner would have to be 8 gauge and a 60 amp circuit breaker would normally be too large for that size wire. Divide the wattage number from step 1 by the voltage number from step 2. If it says 15 1 amps we need to step it up to 12 gauge copper wire. Again in the case of air conditioners we don t need to match up the size of the circuit breaker to the wire sizes.

If it says 34 amps like in the example below we need 8 gauge wire. It did this by opening the switch in the circuit breaker. Although 100 rated devices typically are not available in sizes this small the permitted rating would still be 50a 16a 30a 46a. The common electrical industry terminology would be to say that the circuit breaker or fuse opened or tripped the circuit.