No Power to outside AC unit

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Old 07-05-14, 11:04 AM
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No Power to outside AC unit

I've used my multimeter to test power, none coming to the contactor, so i checked the breaker, reset it, still no power.
checked the line coming to the breaker, no power there. i looked on the inside breaker box, but there is nothing for ac, and no main reset. what am I missing?
 
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Old 07-05-14, 11:57 AM
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verify 230v at the inside breaker check each leg to ground 115V..then outside on the concdenser disconnect or at the top of the contactor 230V 115v again...you might be missing a leg and reading across the pair of wires shows nothing.you should have 2 breakers for the AC one condenser 230V the other the air handler/furnace 115v
 
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Old 07-05-14, 12:00 PM
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Your breaker is probably not labeled. I would try turning off all 2 pole breakers and then turning them back on to reset the breaker for the condenser.

There is still the question of why did it trip.

Burned wire? Bad capacitor? High starting amperage? "Grounded" compressor?
 
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Old 07-05-14, 12:43 PM
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fixed?

in addition to the breaker right by the ac unit, there was another one out by the meter, that one had tripped. flipped and were back in business. now to figure out why.
 
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Old 07-05-14, 01:15 PM
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Usually the one by the A/C unit is just a shutoff..... not usually an actual breaker.
Now you know where your actual breaker is that controls that A/C compressor.

Houston left you some possible problems.
 
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Old 07-05-14, 02:09 PM
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check all of the connections from the contactor thru the shut off into the CB panel...contactor is clean? not black with carbon from arking on start...any bubbling insulation at a connection is an indication of over heating...
 
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Old 07-05-14, 04:09 PM
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Trips after a few minutes, the fan ran well, i plan on checking to see if the compressor is grounded. all the connections looked clean/secure during my initial checkup. anything else i should look for.
 
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Old 07-05-14, 04:28 PM
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If the comp was grounded, it would trip immediately I would think. Doesn't mean that its good, partially shorted windings can pull more current. Things heat up and insulation breaks down.

Ideally you put a clamp on amp meter over the different leads and see where the problem is.
 
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Old 07-05-14, 06:42 PM
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A clamp on ammeter is ideal otherwise you will have to try running just the fan or just the compressor in which case you are starting to get pretty deep into the wiring.

Let us know if you have a clamp on meter or maybe know someone that has one.
 
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Old 07-05-14, 07:01 PM
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A bad run cap can give you a high amperage draw.
Take a look in the panel for a swollen run capacitor or burned wires.

With power removed and while wearing safety glasses, pop the cover off of the compressor terminals to check for melted wires.
 
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Old 07-06-14, 10:27 AM
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copper line to any compressor(wires removed) terminal and shows a reading the compressor is grounded then between the terminals show no reading in the 200range or even audble setting the winding is open....smell the freon on a burp from the suction shradder if it burns smelling it the freon is cooked from a burn out...
 
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Old 07-06-14, 11:20 AM
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i have no ammeter, and checking every connection shows no arcing, or melting, sadly I must throw in the towel and call a pro, i shall report his findings here for all.
 
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