Replaced contactor but AC still not running


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Old 06-16-14, 02:51 PM
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Replaced contactor but AC still not running

Brand New contactor input I'm getting 220 V but getting nothing on the output side or coils. Goodman package unit. Capacitor looks good.

Thoughts ?

Thanks.
 
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Old 06-16-14, 03:13 PM
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If you aren't getting low voltage to the contactor coils, you won't have 240V (not 220) on the output. You need to measure for AC voltage (28VAC?) on the wires coming from the inside unit when the stat is calling for cool. The outside unit often has safety switches for high and low pressure that will prevent starting. They often have times that will require you to wait 5 or 10 min after reapplying power before it will start.

Might help to know brand and models of your system.
 
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Old 06-16-14, 04:00 PM
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Goodman GPH42 Package unit.
 
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Old 06-16-14, 04:10 PM
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You'll need to locate the thermostat wiring where it enters and connects to the unit. In cooling mode you'll need to measure 24vac from C to Y, from C to O and from C to G. It's the C to Y that we are really interested in. If that is present you will need to use the schematic off the service door to locate the high and low pressure switches.... if used. The service manual shows them as optional.
 
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Old 06-17-14, 07:41 AM
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Forgot to mention - only the squirell fan runs. No AC fan or the Compressor running.

So the Thermostat can suddenly go bad when everything used to work fine ?
 
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Old 06-17-14, 08:28 AM
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It might not be the stat...in fact it's unlikely. What can happen is that a fuse blows on a transformer that supplies the 24V. Happens kind of often if all power isn't shut off and wires get shorted out.

It may be a broken or pinched wire. You need to check for the 24V. Since it's a package unit, it should be easy to find.
 
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Old 06-17-14, 08:40 AM
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Does the indoor fan turn off and on with the thermostat or is it stuck on?
 
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Old 06-17-14, 10:21 AM
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"

Does the indoor fan turn off and on with the thermostat


"

Yes.

Also, I checked the 3A fuse on board - & its intact.
 
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Old 06-17-14, 05:11 PM
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Now you'll have to go back to post 4 and make those tests.
Thermostats can go bad.... that's why you use a meter to make tests.
 
 

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