Checking Capacitors

[Little Bill]

Should you remove leads from capacitors before checking them with a meter? My condenser unit for my heat pump isn't running and I suspect bad capacitors.

 

[LarryFine]

Yes, at least all but one.

 

[kwired]

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.

 

[Little Bill]

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.

 

[Knuckle Dragger]

Funny,
For what it's worth I had almost the exact same experience with my heat pump this weekend with the same end result.

 

[Little Bill]

Funny,
For what it's worth I had almost the exact same experience with my heat pump this weekend with the same end result.

Guess that makes us "Master HVAC Techs"!