AC circuit breaker size
- Thread starter russ57
- Start date
- Status
charlie
Senior Member
- Location
- Indianapolis
Re: AC circuit breaker size
No, it is not correct. 440.22(C)
No, it is not correct. 440.22(C)
resistance
Senior Member
- Location
- WA
Re: AC circuit breaker size
I have a question (weak in this area): Wouldn't 430.52 C 1 (ex.1) apply.
I have a question (weak in this area): Wouldn't 430.52 C 1 (ex.1) apply.
charlie
Senior Member
- Location
- Indianapolis
Re: AC circuit breaker size
If you read the nameplate of an AC unit, all of the information is given to you to size the circuit and the short circuit and ground fault protective device (breaker or fuse). This is done because so many heating and AC contractors don't have a clue about how to size the components but they can run a circuit and install an overcurrent device. This makes it foolproof for them . . . sorta.
If you read the nameplate of an AC unit, all of the information is given to you to size the circuit and the short circuit and ground fault protective device (breaker or fuse). This is done because so many heating and AC contractors don't have a clue about how to size the components but they can run a circuit and install an overcurrent device. This makes it foolproof for them . . . sorta.
jtester
Senior Member
- Location
- Las Cruces N.M.
Re: AC circuit breaker size
Charlie is correct. Article 440 does not allow for rounding up of the OCPD. Additionally, 440 applies to hermetic refrigerant motor-compressors, not to any old motor driving a compressor. Hermetic sealed motor-compressors don't have an external motor with a drive belt. The motor-compressor is cooled by the refrigerant.
Second thought, unless the nameplate specifically says breaker or fuse, you are often limited to fuse protection only.
Charlie is correct. Article 440 does not allow for rounding up of the OCPD. Additionally, 440 applies to hermetic refrigerant motor-compressors, not to any old motor driving a compressor. Hermetic sealed motor-compressors don't have an external motor with a drive belt. The motor-compressor is cooled by the refrigerant.
Second thought, unless the nameplate specifically says breaker or fuse, you are often limited to fuse protection only.
charlie
Senior Member
- Location
- Indianapolis
Re: AC circuit breaker size
Actually, if the nameplate doesn't say anything, you are permitted to use either a circuit breaker or fuse. Some nameplates say maximum fuse size and you are required to use only a fuse. Some say fuse or HACR circuit breaker, that restricts the circuit breaker to a HACR type or a fuse.
Actually, if the nameplate doesn't say anything, you are permitted to use either a circuit breaker or fuse. Some nameplates say maximum fuse size and you are required to use only a fuse. Some say fuse or HACR circuit breaker, that restricts the circuit breaker to a HACR type or a fuse.
- Status