AC unit, not working

Gun guru · May 24, 2009

Well as the hot weather comes in my AC unit was not working, I replaced the fuses to the unit, still not working. So I took the cover off the 3 ton condenser unit and -------A mouse got into the unit and Zapped himself across the coil leads. (smells like burnt mouse)---real nasty. Anyway the unit still is not working after putting new fuses in the disconnect box. I guess I need a new coil (or relay also) I dont know. Where do I buy a coil for this? Does Home Depot have these?
Can Anybody help me here? I know that there are some HVAC service guys here.

Anonymous-0 · May 24, 2009

If you are familer with useing volt meter it may nail down the problem without changing parts to locate.First check at relay for "line" voltage.No or low voltage?problem is with other than condenser.recheck fuses,disconnect box,main breaker box and fuses ect..If you are comfurtable useing volt meter and find correct voltage at relay,post back and we will go to next steps of trobleshooting.

Gun guru · May 24, 2009

Okay, I know that there is voltage at the circuit box up to and beyond the fuses, I will check voltage at the coil. I will get back to you later.
I happen to have my VOM with me.

440roadrunner · May 24, 2009

Be VERY careful. I assume this is a 240V unit? If so, sometimes fuses can blow and still check good with a meter, fooling you. If it's 240, make sure you have both legs

I can't reconcile this "coil." The coil of the main contactor (relay) is normally on the thermostat circuit, which is almost always 24-28VAC A mouse should not have affected that, nor should it have hurt the coil itself.

"He" was more likely across the contacts of the thing, and I can see that would make a mess. Probably "carbon tracked" the insulator of the contactor, causing a short,

Can you post a picture of the affected area?

Please be careful. Keep one hand in your pocket!!

Gun guru · May 24, 2009

I can tell you that I pull the connector bar out of the disconnect and the mouse was across the terminal lugs of the coil and there was a hole in the mouse where the current went through him.

I will check this in the morning, I have to take the cover off the unit to get to it. It is an International comfort model, 3 ton, 230VAC, 30 amps.

Anonymous-0 · May 24, 2009

If you are not familier with working with building 120/240 volt,you should not do much more on this.If you are ok one thing you need to watch out for is a (capicator) cylinder shaped plastic cased device about half the size of a soda can,it can bite.when you say "coil"are you referring to the step-down transformer or the low volt coil on the contactor?

bc · May 26, 2009

Guess I'll follow this thread and see where it goes and maybe learn something new. Gun hasn't opened the unit yet, only the disconnect box. So the mouse was in the disconnect box. Guess I've never seen a start or run capacitor or contactor relay that wasn't under cover in the outside unit itself. Never seen a coil in the disconnect box. Just the round fuses or breakers.

Should have voltage on both sides of the lugs with new fuses or reset the breaker. Probably threw the main breaker in the main panel. Mouse may have arc'd and melted the plastic and terminals. Probably time for a new disconnect box. Some of the wiring and terminations may have burnt up/melted.

Guess I couldn't rule out that the mouse caused a surge that burnt out the relay or a capacitor or maybe something in the main circuit board.

AC unit, not working

Gun guru

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Anonymous-0

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Gun guru

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440roadrunner

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Gun guru

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Anonymous-0

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bc

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