Disconnect sizing

[tank728]

Gentleman,

I have a air handler unit with mca 48 amps and a mocp of 65 amps. Am I okay to install a 60 amp unfused disconnect locally for this unit?

Thanks

 

[Krusscher]

What size OCPD are you feeding it with?

 

[infinity]

Yes. If I remember correctly the disconect can be rated at 115% of the total of the loads in multi-load AC equipment. With an MCA of 48 amp the actual total load times 115% would be less than the MCA so the 60 amp disconnect is fine.

 

[tank728]

What size OCPD are you feeding it with?

RFI has yet to come back, currently the drawing states 30 amp, haha. For discussion sake, assume 65. Do you concur with infinity in post 3?

 

[Krusscher]

RFI has yet to come back, currently the drawing states 30 amp, haha. For discussion sake, assume 65. Do you concur with infinity in post 3?

Yes it appears it should be based of MCA but it also may have to be rated for the corresponding HP rating instead. You can go through past post on this subject but there is quite a bit of back and forth and I'm not sure which is right or wrong. Probably has more to do with what the AHJ.