Ac fan not working

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Old 07-27-18, 03:28 PM
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Ac fan not working

i tested the capasator fan...4.0....herm...35.0 120 v on each leg. No fan no hum nothing. Air handler in attic was blowing warm air.
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Old 07-27-18, 04:19 PM
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It's not clear how you checked the capacitor. Do you have a meter that measures capacitance?

Is the contactor engaging (pulling in) when the thermostat calls for cooling? If not, you need to determine why. There is a 24VAC transformer in the house, usually in or near the air handler. The 24VAC gets sent to the thermostat, and when it calls for cooling, it sends the 24V to the outside unit via a cable. Some air handlers have a fuse (typically 3A), some have a condensate float (shuts off outside unit if condensate drain plugs up). In the outside unit, some systems have a low pressure and/or high pressure switch. All are in series with the 24VAC going to the contactor.

If you don't have 24VAC at the contactor (typically the side terminals), you need to determine why. Note, you can turn off the power to the outside unit (should be an electrical disconnect located near the outside unit) to minimize the chance of getting a shock (240VAC) while checking for the 24VAC.
 
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Old 07-27-18, 04:54 PM
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Hi, thanks yes I have a volt meter. Does the contactor have one side have two terminals for ac current 120 and120 input ?

I found the schematic for the unit. I will go tomorrow and take pictures of the connections. This will help me ask the correct questions.
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Last edited by clubcar; 07-27-18 at 05:36 PM. Reason: added comments
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Old 07-28-18, 04:32 AM
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Originally Posted by clubcar View Post
Hi, thanks yes I have a volt meter. Does the contactor have one side have two terminals for ac current 120 and120 input ? thanks
The outside unit runs on 240VAC. The 240VAC input normally is wired to the T1/T2 terminals. The L1/L2 terminals connect to the compressor and condenser fan motor.

The contactor is a relay. The 24VAC control voltage coming from the thermostat engergizes the coil winding on the contactor, pulling the contacts down which closes the circuit sending 240VAC to the compressor & fan motor. If you're missing either the 24VAC or the 240VAC, the outside unit won't run.
 
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Old 07-28-18, 09:27 AM
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Welcome to the forums.

You must confirm 240vAC across the contactor input...... not 120v and 120v from each side to ground.
 
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