120/240 volt--general question
An appliance uses 4 wires like posted. One is a ground- this is not always present thus a 3 wire plug is sometimes seen and the neutral attaches to the case via a strap. One is the neutral. The other two prongs are both 120 volts.
To get both 240 and 120 V off the same plug, the appliance will only attach a connecting wire to one of the 120V lines and use the common neutral. The heating element (or motor or whatever needs the full 240V) would attach to both of the 120's. Thus one plug carries the supply for both the 240 needs along with the 120.
Last edited by Daltex; 01-03-2012 at 07:11 PM.