My IEC Contactor Coil keeps overheating

I have a 3ph IEC contactor with 120v coil voltage. For some reason, the coil starts heating up like crazy when I run it. I have 121v on L1, 120v on L2 and 121v on L3. I re-connected all the wiring to make sure there were no loose connections but still it keeps heating up when I energize the coil. What could be causing this?


Science Advisor
Gold Member
How is the coil connected in the contactor? Is there a transformer using two of the phases to get the 120 volts? If you are connecting the coil across two of the phases directly, you'll need a 230 volt coil.


Science Advisor
Gold Member
Have you measured the voltage across the coil itself? One voltmeter probe on each terminal of the coil.

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