Shouldn't there be three wires from the switch to the 240v motor?

by Dan in Iowa
(Southeast Iowa)

I installed a dedicated 240v circuit to the new Sanborn 60 gallon upright unit.


When wiring the cord to the switch, there are typically (2) 120v leads and a neutral and a ground.

On this unit, there is only a black and a white wire to the motor.

How is this possible? Help.

Comments for Shouldn't there be three wires from the switch to the 240v motor?

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Feb 10, 2016
The three wires
by: Doug in s.d.ca

Not unless the device needs 120 for some reason:

There is 120 from neutral (white) to either of the "hot" (black, usually, or blue or other color sometimes). Each 120 is half of a 240 only circuit, so you have 240 across the two "hot" wires - the neutral is not needed for a 240 device.

For the motor, you need two wires for 240, and MAYBE a (green) ground, but usually that's only to the frame of the overall unit, with the motor getting ground through the mounting bolts/screws.

The wires to the motor are black and white in case the motor is wired internally for 120.

HTH.

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