AC max breakers

[Richard W. Washington]

ac max is 30 and builder has 35 saying that it will trip in summer if put down to 30 even though manuf. recommended maxi 30. builder said he's talked to electricians about this and they told him 35 amp is ok. he said this gets called out all the time by inspectors. is he right?

[Marc D. Shunk]

When the dataplate says "Maximum fuse or breaker size", that's all the bigger you're permitted to use. Period. End of story. Call it out and stand your ground. Let some other fool say it's okay if they want to.

[brian winkle]

But first see if the disconnect has 30 amp fuses in it.

[brian winkle]

I didn't notice you were in Texas. Perhaps this is okay then, as I've heard "everything's bigger in Texas".

[Marc D. Shunk]

Originally Posted by brian winkle

But first see if the disconnect has 30 amp fuses in it.

Excellent point. You could, in fact, serve an a/c unit with a pretty stout breaker in the panel if the disconnect contained appropriately sized fuses.

That never crossed my mind, since almost nobody uses fused disconnects for residential air conditioners in my area unless the dataplate specifically says "maximum fuse size" and omits the word "breaker". A fused a/c disconnect is 30 dollars, plus 7 bucks a fuse. An unfused a/c disconnect is 9 dollars.

[Mathew Hawley]

Richard here is what I report when I run into this situation:

The AC condensing unit's data plate calls for a maximum fuse size of 30-amps and the unit is currently fused on an 35-amp breaker. This condition can void the manufacturer’s warranty and does not provide the proper overcurrent protection for the unit.

Keep calling it out, you are correct.

I have called the manufacturers regarding being only 5-amps over. Per manufacturer, some unit can be 5 over. Just call them with the mod # and ser #

Most manufacturer reps are very helpful. They are a good rescource to use when needed.

[Richard W. Washington]

i'm going to call the manuf. rep. and report back what he says.