Checking Capacitors

All leads from one terminal unless you know there is no possible circuit other than the capacitor being tested for your test current to flow through. For a single value capacitor anyway, dual value caps could have multiple circuit pathways and need more than just one terminal disconnected.

Bulge case in aluminum run capacitors is kind of automatic indication it is no good, they have a fuse link that pulls open when pressure builds up to cause them to bulge.
 
Very strange!
I checked the capacitor, it was good.
I checked the contactor, including the coil. I even pulled it off to check the contacts and coil resistance, all good.

Put everything back and was going to check further. Now I had the disconnect pulled out, but the indoor unit was powered. As I was sitting there wondering what to to check next, I heard the contactor pull in. Had 24V on the coil and contactor working. Put the pull out back in and it fired right up!

Only thing I can think of was a loose connect somewhere, or coil or contactor stuck. So either taking the wires off and back on fixed it, or manually operating the contactor, got it going.
Whatever it was, I hope it stays and I don't have to have a tech come out.
 
Little Bill said:
Very strange!
I checked the capacitor, it was good.
I checked the contactor, including the coil. I even pulled it off to check the contacts and coil resistance, all good.

Put everything back and was going to check further. Now I had the disconnect pulled out, but the indoor unit was powered. As I was sitting there wondering what to to check next, I heard the contactor pull in. Had 24V on the coil and contactor working. Put the pull out back in and it fired right up!

Only thing I can think of was a loose connect somewhere, or coil or contactor stuck. So either taking the wires off and back on fixed it, or manually operating the contactor, got it going.
Whatever it was, I hope it stays and I don't have to have a tech come out.
Click to expand...
Stuck contactor (in open position) should likely have burned out coil when power was applied to the coil.

Sort of sounding like something happened in the control circuit and you weren't getting power to the coil.
 
kwired said:
Stuck contactor (in open position) should likely have burned out coil when power was applied to the coil.

Sort of sounding like something happened in the control circuit and you weren't getting power to the coil.
Click to expand...
I looked at the board but didn't actually touch it. Well, other than maybe some of the wiring that goes to it when I disconnected the cap & contactor.
 
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