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Tarheel Technician

Run capacitor question

7 posts in this topic

Whirlpool a/c model #: ACM102XK0

This may be a stupid question, but when looking at the wiring diagram, it shows a run capacitor hooked to the start winding of the compressor. Would this not make it a start capacitor??

 

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Well, putting my stupid question aside, this air conditioner was working fine when I checked it, but customer said the other day, when the compressor cut on....it would just humm for a few seconds then quit, then do it again, then quit, etc. like the overload was kicking in. He said the breaker (he has the old cartridge style fuses) got real hot. I looked and it was black around that particular breaker.

I'm thinking the culprit is a bad breaker, but I'm wanting some other input. When I checked the a/c, it ran fine, pulled about 7.5 amps (rated at 8.9 amps).  I couldn't get it to duplicate the problem for me, except when I just turned the thermostat back, then immediately back on again (which I knew would cause the overload to come into play). It tried about 3 times to cut on (pulling about 40 amps) and the 4th time, the compressor cranked up and ran fine. But under normal operating conditions, it ran flawlessly.

I did notice that the a/c is not on a single outlet, there were other receptacles run on the same breaker. But nothing that pulled a lot of amps were on those receptacles.

Anyone else seen bad breakers cause this to happen?

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Heres another dumb question ...how many acs was they running on that house?

 

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Hey,

Check your contactor coil to see if it's getting the proper volts and if it is then maybe it's going bad, not pulling in the contactor as it should or the contacts on the contactor are going bad.Either way,if you have volts getiing to the load and the load isn't working the load is bad.I would also check for any bad connections from the transformer to the coil to make sure it isn't a broken connection , making nad breaking.

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:dude: First your capacitor question. A start capacitor is utilized to boost power to the motor through the windings, and then drops out as the motor speed comes up. A run capacitor remains in the circuit as long as the motor runs, to create a phase shift, resulting in a more efficient operation.

My gut feeling is that your breaker is bad. Scorching at electrical connections is most commonly caused by poor electrical contact. Excess amperage will usually throw the C/B before any damage to wiring occurs. Most electrical fires are from bad connections arcing/overheating, rather than shorts.

It also sounds like the compressor is having trouble starting. You may consider installing a start-boost capacitor, like SUPCO and other companies offer.

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tarheel I keep two different start boosters on my truck ,a hs850 and a hs650  sometimes I hook both of them up at the same time. this sometimes frees up the compressor if its stuck, if all else fails hit the side of the can with a hammer this sometimes knocks it loose if its been sitting up specially on them coffee can models IE rotary compressors :dude: most ac s I have seen have a start cap  not many down here have run caps  the start cap goes out of the circuit after 15 seconds or so

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