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Matt, How Do You Check a Dual-Run Capacitor Under Load?


In this edition of "HVAC Skill Builder," Matt discusses how to check a Dual-Run Capacitor Under Load.

Q: How Do You Check a Dual-Run Capacitor Under Load? A: Well, the formula to do that is going to be 2650 times the amps divided by the volts. And the way that works is if you take 2650 times the amps of the compressor, for example, you're going to get the amps or 2650 times amps and divided by the volts of the compressor. And that's going to be from common to hermetic on your capacitor. And once you solve for that, that's going to give you the microfarads for the compressor. And then you go back and do the exact same formula 2650 times amps of the fan motor divided by the volts of the fan motor from common to fan and that's going to give you the fan microfarads. So have those two solved, you can compare it to what is there and figure out if it's within tolerance or not within tolerance. So again, the formula as a recap is 2650 times the amps divided by the volts, and you do that for hermetic and for fan, and you'll be able to get your microfarads under load while the system is operating.

Matt Akins is the Manager of HVACR Technical Education at ACCA.


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Posted In: HVAC Skill Builder, Technical Tips

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