I have a 3 Hp 1 Ph 230 V motor. The incoming power changed from 242 V to 252 V and now it trips the overload in the control panel. The specs say not to run above 250 V. I’ve checked the motor and tested it on a test panel and all seems fine. Is there any way to reduce the incoming voltage? The electric company says they are within their acceptable range.

  • \$\begingroup\$ @DKNguyen it seems that it is a single-phase motor. \$\endgroup\$
    – user57037
    Sep 22, 2022 at 5:27
  • 1
    \$\begingroup\$ @mkeith Oh I think I might have read 3 Hp as 3 Ph \$\endgroup\$
    – DKNguyen
    Sep 22, 2022 at 13:16

1 Answer 1


I suspect that the control panel overload is a bit too sensitive. But you might try reducing the size of the start or run capacitor by 10% or so, as it's probably the starting current that trips the overload.

Otherwise, you could utilize a buck transformer to reduce the voltage. The motor probably draws about 12-15 amps, so you could use a 200 VA 240 V to 12 or 16 VAC which will drop the motor voltage to 240 VAC or 236 VAC.


  • 2
    \$\begingroup\$ Good call on the buck transformer. I was gonna suggest same! Very clever transformer application that I've found few people aware of. \$\endgroup\$
    – Kyle B
    Sep 22, 2022 at 6:19

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