Am I doing any disservice to my Central AC Condenser by using 30A fuses in a 30A rated disconnect on a 30A 2P breaker, 10-2 wire? It's a Trane Condenser, only 1 year old.
The side of the Condenser says it's rated for a max fuse size of 25A. Should I switch out the pull fuses from 30A to 25A? Just want to be sure I'm not harming the unit
Well I'm no guru but I'll throw my 2 cents in anyway First of all there's no need to even have fuses in the disconnect if you have a breaker. Just one more thing that can go bad. And I don't see how it would hurt the unit, but really changing a fuse or breaker is really simple & not too expensive I'd think you'd be better off just replacing the breaker and/or fuses to be safe.
10-2 wire can handle 30 amps and the breaker/fuses are meant to protect the wire from overheating/melting/damage. If there is a dead short then a 30 amp will pop as fast as a 25 amp. 25 amp breakers are rare and I have not seen any lately. fuses are available in 5 amp increments. May want to post in the electrical forum at the top of the page and see if the licensed electricians think differently. If the compressor stalls then a 30 amp may take 1/2 a second longer to pop and that won't hurt the compressor, just generate a little bit of heat.
"Cut it twice and it is still too short".