Why do i have to replace my start capacitor every year?

Question

We bought an old house and remodeled it. In the remodel, we had the Central AC/heat replaced. Got a bad AC contractor and he miss matched our 'A' coil size to the compressor size. We didn't find out until the summer time and he was long gone. We compensated by adding a window unit on the opposite end of the house. But every year during the hottest months, I'll have to replace the start capacitor for the fan. (I suspect it's only for the fan, it has 3 prongs- fan-herm-c). I've replaced it 3 years in a row. The AC guy in the area says just to expect it, and told me to put a hard start kit on as well, because we live in a rural area and it will help with low voltage problems and protect the compressor. So my question is - should I just expext to replace this part every year, or is there a way to protect this from happening without replacing the whole unit again?

Answer 1

keep your condenser coils clean that will help the stress level on the cap but yes in 100+ caps will go

Answer 2

The fan doesn't use a start cap,just a run cap.The 3 prong cap that you are talking about is a dual run cap.(compressor & fan)If it keeps going bad on you it might not be the right size or the wiring might be wrong.The low voltage won't cause it but high voltage will.Unless the compressor has starting problems there isn't a valid reason to add a start capacitor.Look carefully at the wiring again because the dual run cap should not go bad that often.Good luck.

Answer 3

Difficult to say but for now replace the capacitor with one that is a little bit heavier. And buy a good brand name. Not all capacitors are equal these days.

Further more look at

http://www.uoguelph.ca/~antoon/gadgets/c...

http://www.csgnetwork.com/capqualfactcal...

Answer 4

The Capacitor you talk about is a run capacitor and they fail for many reasons so lets see what is up. Yes low voltage can cause the fluid to boil in the cap and swell it up. A hard start with a relay to drop out of the circuit will help. The lights in the home will dim down if the compressor is having a hard time starting. If you have a TX valve on the evap coil you should have a hard start kit installed. Short cycling or power outages when equipment is on can cause this, back to hard start. The wrong size cap will cause more than the cap problem, the wrong size cap will make the fan and compressor run hot and go out on overload. Go by the lights in the home they should not dim real bad if they do that tells you supply amperage is low.