AC capacitor(s) both in less than a month

austin20

Had to replace the one for the upstairs system about three weeks ago and the downstairs system today.

Warbirds

Bummer- While I dont know jack about AC units- electronic systems drawing increased amperage beyond the capacitor design will certainly kill a capacitor. I could see this being a culprit with AC stuff.
Keep it cool and run the amps a capacitor is designed for and it will last a long time.

All that speculation said- a popped capacitor is a symptom not the root cause, more often than not.

I dont know how it works or the interdependencies but one after another would indicate something is pushing/drawing excess amperage into that system.

PS- I hate sparky stuff!

casting

I've got a unit that quit and I'm sure it's a capacitor. I just can't get it out of the window w/o serious help. There's multiple You-Tubes on it. This unit is about 13 yrs old but seldom used. Most likely time to give it up and buy a new one.

Hessian

A couple of reasons I can think of for this. One is what we call short cycling. Short cycling can happen when a compressor is shut off and restarted quick (within a minute). The heat from normal run plus the heat from a high amp hot start will trip the auto-reset heat protector in the compressor, sometimes the circuit breaker but not always. Then it can repeat (over and over) as the compressor retries to start in short cycles. The heat builds from the repeated start cycles, the weak link eventually fails. A cool compressor starts easier than a hot compressor for multiple reasons.

Another reason is the supply voltage, usually too high, sometimes too low. The utility sometimes raises the line voltage trying to get more use out of old wires. Anything over a 15% increase is likely to cause issues. maybe catastrophic failure. Watts is the measure of the amount of work electricity can do amps X volts = watts. One bad compressor can suck down the voltage (short cycle) and affect another compressor. And/or the breaker pops and when you reset two compressors on the same supply lines short cycle, not enough juice in the system.

Less likely is somebody did a service on both units and screwed it up, overfilled, moisture in the system etc. A damaged partially shorted coil inside the compressor can cause a high amp draw, unlikely as you have two compressors doing the same thing.

Best guess is your circuit breaker has been popping and you reset too quickly starting a short cycle in the compressor(s). Or your supply voltage is too high because your utility has raised it, it happens. Or also possible high electricity usage, dinner time, oven, maybe the washer and dryer going at the same time causes a low voltage situation.

Hope I didn't confuse you too much.

select-fire

When a unit starts eating capacitors the compressor on starts is pulling more amps than it did when new. In other words it is about to go out. Then a hard start kit can be installed to make up the difference with the capacitor. Then the compressor is living on borrowed time which could be a little time or a few years.

remingtonoaks

Starting capacitors just like a battery. It gives it the shot of electricity to start the unit, once again it is started a starting capacitor is no longer needed. Just like every other type of battery, with age they wear out. But for what they do they're pretty cheap to buy

bustedknee

I lost 2 caps over a one month period. Both blew during heavy thunderstorms with nearby lighting strikes.
I ordered caps with a higher voltage rating and have had no problems since.

1. Lower voltage rating caps are cheaper
2. Job security for A/C sales and repair.