contactor question


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Old 08-14-15, 02:34 PM
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contactor question

Is it normal to see some minor pitting or sooting/blackening of the pad contact points of an AC contactor?
 
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Old 08-14-15, 02:42 PM
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Yes, since the contactor is switching inductive loads (compressor and condenser fan motors), it's normal to get a little arcing when the contacts open & close. As long as the contacts aren't badly pitted to where there's little contact left, you should be okay.
 
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Old 08-14-15, 02:43 PM
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Yes. Emphasis on minor....................
 
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Old 08-14-15, 03:30 PM
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So they all get changed after a while? Like preventative maintence yearly tune up thing?

Reason I ask I see a bit of burn on the contacter pads on mine.... its been in service for 2 cooling seasons. Is that too soon to see signs of heat?
 
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Old 08-14-15, 04:01 PM
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You can replace the contactor if you feel the need, however it's not something that usually gets replaced unless it's causing a problem. My 25 year old system is still all original (capacitors and contactor).
 
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Old 08-14-15, 05:19 PM
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The contactors of 25 years ago will hold up better than today's as they were built much better.

A/C contactors used to be $35-$50. Now they're $10-$25.
 
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Old 08-14-15, 05:52 PM
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Are they universal? When replacing one do I have to use the same part that came with the unit or can I use different one as long as the ratings match?

Are there better quality replacement contactors?
 
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Old 08-14-15, 08:05 PM
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The ratings that are important are the coil voltage (almost always 24 volts AC but there are a few exceptions), the contact voltage which must be a minimum of 240 volts AC and the amperage rating which must be sufficient to handle the load of both the compressor and the fan motor together.

The voltage and amperage (often motor horsepower is listed in addition to amperage) MUST be at least the same as the original equipment but having higher ratings is allowable and may give longer life.
 
 

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