AC Compressor Fails to Start

[Randy Roberts]

I have three 18 year old carrier units. I was checking R22 pressures o all. Scrader valve apprarently stuck open and leaking on unit #3. Th next day I found cooling fan running with compressor not running bu bubbles comming out of scrader valve on suction line. I checke pressures on high an low side, both about 125. The next day I installe manifold gage and started unit. The suction started to drop and I ope the R22 supply. Pressure dropped to about 80 when compressor stoppe running. The fan kept running very slow. Checked 220 line and found lu on panel beaker melted away from buss bar. Replace mini 220 beaker wit full size 220 breaker. When stating system the condensor fan runs slo until contactor closed by thermostat then fan runs full speed. Th compressor tries to start but fail after 3 seconds. The system wa running and cooling well before I tested the pressures. At least it wa running better than the other two units.

Here are my questions:

1. Is there a low level freon cutout switch shutting the compresso down?
2. Did a loss of freon and or oil cause the compressor to seize?
3. Did the faulty breaker cause the motor to sort-out or did a hig current from low freon overload the breakers or both?
4. What do you recommend?

Thanks for any advise, Rand

-- Randy Robert

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[RP]

Not at 80psig.

Could've been that, or maybe a slug of liquid from somebody randomly dumping in freon.

Possible, not likely, but possible.

Two things:

1) A new unit 2) That you quit while you're ahead.

Why would you be checking pressures when you obviously know nothing about air conditioning systems. What good is knowing the pressures when you don't even know what they mean? You don't just dump freon into a system on a whim, hell you probably caused every bit of the problems. I recommend that you call somebody competent to check the systems periodically; it'll be less expensive for you in the long run.

hvacrmedic

[hvactech2]

Some units do have a low pressure switch but the fact that it tries to start says it isn't that.

The only way to find out what is wrong is to have it diagnosed by a local pro who can take the needed readings. it could be any one of a number of things.

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[Stormin Mormon]

I have three 18 year old carrier units. I was checking R22 pressures on all. CY: Why? Were they working poorly? Did you check them running, or turned off? Were you calculating superheat?

Scrader valve apprarently stuck open and leaking on unit #3. The next day I found cooling fan running with compressor not running but bubbles comming out of scrader valve on suction line. I checked pressures on high an low side, both about 125. CY: Sounds lke compressor not running.... but you already said that.

The next day I installed manifold gage and started unit. The suction started to drop and I open the R22 supply. Pressure dropped to about 80 when compressor stopped running. CY: Wonder if the two factoids are related?

The fan kept running very slow. Checked 220 line and found lug on panel beaker melted away from buss bar. Replace mini 220 beaker with full size 220 breaker. When stating system the condensor fan runs slow until contactor closed by thermostat then fan runs full speed. The compressor tries to start but fail after 3 seconds. CY: Could be locked rotor, or possibly bad starting components. Or maybe not getting enough power.

The system was running and cooling well before I tested the pressures. At least it was running better than the other two units.

Here are my questions:

1. Is there a low level freon cutout switch shutting the compressor down? CY: Possibly. I'm not sure about those units.

1. Did a loss of freon and or oil cause the compressor to seize? CY: Doubt you'd lose enough oil. But, if you were injecting liquid, you might have slugged the compressor. Not sure about AC compressors, but I have known of an ignorant person to spray ether into a generator spark plug hole, and then the next time starting it threw a piston rod. So, you might have rinsed the lube out of the piston chamber of the compressor.

2. Did the faulty breaker cause the motor to sort-out or did a high current from low freon overload the breakers or both? CY: Not sure about this.

1. What do you recommend? CY: At this point, it sounds like you made it worse instead of better. It's a learning experience. I'd suggest check for 220 volt power at the compressor. And then change out the compressor starting components. Maybe a super boost kit. Cheaper than the next step -- which would be to replace the condensing unit.

Thanks for any advise, Randy CY: Wish I had better news.

[Randy Roberts]

To set the record straight there was no freon added to this unit. Thanks for those with helpfull hints. If the hvacmedic replies are going to be errogant then the advise will be of no benifit to this forum. Those of us who want to learn and make better choices when selecting contractors for repairs will have to seek advise only from those who are polite and helpful. Are you looking for repeat buisness or just bolster you own ego.

Thanks again to the others who were of help.

Have a nice day. Randy

[Carolina Breeze HVAC]

RAndy:

Arrogant replies are not as arrogant if you are willing to learn from those of us that deal with stupidity on a daily basis, those of us that deal with other so called contractors screw ups on a daily basis, and those of us that might know a bit more than Joe Blow down the street. As far as business on here, or off the net period, I have gotten MORE for being up front, perhaps NOT saying what you want to hear, and not being sugar coated. After a while, people hate to be bullshitted and I have actually had people in my area read this forum and call....sure, I lost a few, but here is a hint...if you dont like what you might be told, I could give a damn less if they are on my customer list, since those that are, know that if I tell them soomethings wrong, they KNOW its wrong.