Bad Contactor ?? (HVAC System)

Old 06-19-05, 06:55 PM
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Question Bad Contactor ?? (HVAC System)

My outside does not work (the indoor blower runs fine). The contactor does pull in after 5 minutes.
After reading posts on this forum, I opened my AC unit panel on the side and checked the voltage at the contactor. There are two wires coming in from outside and are connected to points marked L1 and L3.The other side of contactor has two points marked T1 and T3. I tried to find L2 and T2 but they are not there. Besides there are some small wires coming in and going out also, like one from a timer set to 5 mins.
The voltage b/w L1, L3 is 240 volts
After contactor is pulled in (after 5 minutes of turning thrmostate to cool), the voltage between T1 and T3 is still 0 volts. I expected it to be 240v also.
Here are the readings after contactor is pulled in:

L1, L3: 240v
T1, T3: 0v
L1, T1: 0v
L3, T3: 240v

Does these reading mean contactor is bad and need be replaced or the readings are normal? The contactor looks ok, no sign of burnt wire etc.

Old 06-19-05, 07:22 PM
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You should be getting 24 volts at the coil which is T1 T3 and 220 volts at L1 L3, turn power off and check to make sure your wires going into the contactor and the coil didn't come lose , you may have a bad coil being your not getting the 24 volts needed to pull in the contactor closed.
Again make sure the breaker is off which powers your unit and double check all of your wiring.
My guess is a bad coil.

Old 06-20-05, 11:39 AM
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Where is the coil located? Is it the small (red-colored) thing behind the contactor or something inside? If I push contactor in with a stick, should it start then?
Old 06-20-05, 01:29 PM
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The contactor does pull in after 5 minutes.
If I push contactor in with a stick, should it start then?
be the same as above

If you have 220V in like you say then it should run. See if you have 220V on the out--- side of the contacitor when its pulled in can you have bad points there???? or is it in the unit.????


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