Replace contactor relay??


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Old 05-12-09, 02:24 PM
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Question Replace contactor relay??

I have a Goodman central air unit outside. Inside turns on/blows but outside unit, fan etc. don't. There is a sort of electrical hum that it will make. Fan/motor turns freely by hand. I can shut the unit down, tap on the relay, turn it back on and it runs. Of course when you shut it down and turn back on again it goes back to not running unless you repeat the tapping on the relay. I'm assuming the relay is just worn out and needs replacing. I'm also assuming I can replace it myself without shocking the begeezes out of me if all power is turned off at the breaker box?? Any suggestions, words of advice (and/or caution) would be greatly appreciated.
 
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Old 05-12-09, 07:21 PM
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Make darn sure the power is off to both the indoor and outdoor units. Make a sketch of where each wire goes, do not lose the sketch. Remove the wires, remove the contactor from the cabinet, look on the side of the contactor for the amerage rating. For example, it might say 25 amp. Next look at the voltage for the magnetic coil which is probably 24 volts, then look at the contacts. Residential A/C unit contactors are usually 2 pole with one set of moveable contacts for one pole and a solid brass bar for the other pole. Get a new contactor making sure the amp rating is at least the same as the old one. It's ok to go higher. I usually kick it up one notch- for example replace a 25 with a 30, but ensure that the new one will fit in the cabinet if space is an issue. Wire up the new contactor using the sketch. Let us know how you make out.
 
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Old 05-13-09, 11:55 AM
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fried relay

Thanks daddyjohn, I had already done just that as far as turning off all power, making a sketch, numbering the wires, etc. Upon examination once it was removed it's no wonder it was sticking, the contact points were pretty much fried. I had read these things should be changed every five years. This unit was worked on last year for the same problem by a "side job mechanic" that supposedly was doing the lady a favor and only charged her $50. Since the part is going to cost pretty much that, I'm betting all he did was file the contacts. Another thing I read one shouldn't do.

Couldn't find the part locally size wise to fit the cabinet so I had an electrical supply company in the area order it for me. I'll let you know how things turn out when it comes in but I don't anticipate any problems.
 
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Old 05-14-09, 03:34 AM
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No way are resi size contactors $50. More like less than $20. BTW- don't ever file the contacts, you file the silver right off when you do that.
 
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Old 05-25-09, 02:53 PM
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Ordered from electric supply, square D definite purpose contactor. 2-pole, open type. Coil 24V - 50/60 HZ Cost: $45.59
Except for manufacture it was identical to the one I removed and was a perfect fit. Wish I could have found it for $20. but on the up side at least I didn't have to pay a service call. Air conditioner is running like a champ.
 
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Old 05-25-09, 05:00 PM
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Sounds good. We're happy you have your cooling back. Thanks for the feedback.
 
 

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