Electrical Question

[Lee Schierer]

I have a four wire cable for a 240 volt appliance that is currently hard wired. It will be replaced tomorrow with a new appliance and I want it to plug in for easier servicing.

I have a dryer/stove receptacle that has three terminals labeled BLK, RED and GR. The wire has red, black, white and bare copper. Am I correct in assuming the GR terminal is for the ground wire and not the neutral wire so I really need a four wire receptacle?

[Ken Fitzgerald]

Lee,

The reason for the 4 wire receptacle and plugs....for straight 220/240 you need 3 wires....2 hots and a ground.

If, however, your device also needs 110/120...like the clock on a kitchen stove, for instance, then you also need a neutral to provide a return for 1 of the phase to produce 110/120. So you need 4 wires..2 hots...a neutral and a ground to provide both 220/240 and 110/120.

[Tom Godley]

It was normal years ago for only three wires to a dryer - two hots and a neutral. The neutral was required for the 120v motor. Often you would see a separate wire from the cabinet to a water pipe -- for the ground.

If the new appliance is four wire than you will need a four wire plug and receptacle.


It has been a long time but my memory is that the old three wire outlets for a straight 240 stove were different than those for a dryer because it actually was a ground in the stove and not a neutral.