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Using 120VAC on a 100VAC relay coil?


Robin S.

Jan 1, 1970
I'm making something of a motor controller to run a motor.

I bought a surplus relay that has a coil voltage rating of 100VAC. Obviously
I would like to run it on 120VAC. I don't have the relay in front of me so I
can't say what the resistance is.

The relay is made by Omron.

Would it be harmful to run the relay directly on 120VAC? Is there a
significant tolerance on the voltage rating?

If not, I have been told to just try different resistor values by connecting
them and testing with a volt meter across the coil because it is an
inductive load.

Thoughts? The coil will have to be on for several minutes at a time with a
duty cycle of perhaps 80% sometimes.