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This question is a follow-up from a related question about an AC tech recommending a likely unnecessary fan motor replacement. See Rust on outdoor ac fan motor? Tech recommends replacement?

I'm trying to measure the current draw on the condenser fan motor and compare it to the nameplate FLA of 1.1A

With a current clamp on the fan's 3 different wires, I measure 0.7A on the purple wire which connects directly to the capacitor, 0.9A on the black wire, and 0.4A on the orange wire. Is there any sort of adding/subtracting involved in finding the current draw, or is it the maximum, etc.? Apologies for the ignorance on understanding exactly what I'm measuring here.

For reference here are pics of the wiring diagram and the actual unit: Wiring diagram from unitPicture of unit

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Your readings appear to be normal under the circumstances. The three motor wires are cable tied together at the top and that will distort the readings. You'd expect to see the same reading on the orange and black wires because they are your L1 and L2 connection points. The FLA is the maximum the motor's designed to operate at, not necessarily what the current draw will be. Most meters have an error factor of 1 to 2%. There's no real "adding or subtracting" involved. My last AC unit, Rheem, had two oil ports on the motor so check to see if you've got those and squirt some motor oil in them if you've got them.

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  • I agree that the motor is running below FLA and this is normal. It would not hurt it to run at FLA but the fan blades would have to be more aggressive , possibly even a coil clean but I would expect the company did that on the service.
    – Ed Beal
    May 24, 2022 at 13:11

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