I have a pool pump that I recently bought used to replace a failing pump. The motor is rated for either 115v or 230v (low/hi switch) operation.

My previous pump was wired with a 12 gauge line to a L5-20 125V 20A receptacle. So, I replaced the standard 110v three prong line on the new pump with the 12 gauge line.

Will having the 125v wired into the 115v pump leads cause a problem with the motor? Meaning, is that additional 10v going to burn out the motor?

L5-20 plug:

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1) American house-current power is commonly described as anything from 110VAC to 120VAC.(Similarly, the higher voltage obtained by using both phases is called everything from 220VAC to 240VAC.) I believe this is mostly a historical artifact, and appliances labelled for anything in the respective range should work with any voltage within that range.

2) Fittings are overdesigned slightly for safety. So a receptacle intended for use with American house-current power will typically be rated for 125VAC. That doesn't mean it necessarily supplies 125VAC, only that it's tested and promised to be safe up to that (higher-than-needed) voltage.

  • 1
    120/240V single split phase systems supply 120 and 240 volts RMS +-5% (114-126, 228-252). The house wiring can have anther 3% drop, so you're talking ~110V or ~221V at the device (which may be where the 110/220 comes from). The 3% rule is not an actual rule, just a recommendation. So you could actually see even lower voltages. Devices will commonly be rated 125V and 250V.
    – Tester101
    Jun 8 '14 at 12:48

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