Sunday, November 1, 2009

Breaking a 240 circuit down to 120V

The Red and Blue bars represent the powered bars of a single phase (residential) service panel. A breaker attaching to one phase (or one bar) gets 120V of power. A breaker attaching to both of the red and blue bar will achieve 240V. To break 240 down to 120V you must drop one of the power legs.



Click on picture to read!














As you can see above the red wires are capped off , both in the panel and at the device location. The Green (ground) and the white (grounded) conductors attach to the ground bar in the panel. (Main panel configuration, Sub panel has different rules)

The Black wire was relocated in the panel to a single breaker, and at the device, attaches to the brass screw.

The White wire at the device attaches to the silver screw, as it is the return path for power from your appliance.

The green wire (or bare) attaches to the Green Screw. This is intended to be the safety ground.

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