Understanding 120/240V Wiring Color Code | DoItYourself The White Wire in a 240V Circuit. There is one case in which a white may be used to carry ungrounded potential that is still in conformity with the most recent cycle of the NEC. That is when a cable is used to feed a straight 240V load. If an appliance does not need or use 120V power, but only needs and uses 240V power, a standard 2-conductorAuthor: DIY Staff[PDF] A FIELD WIRING DIAGRAM A 240 VAC SINGLE PHASE for the 240 VAC rated microinverters should be within the following ranges: line to line - 211 to 264 VAC, line to neutral - 106 to 132 VAC . FIELD WIRING DIAGRAM 240 VAC SINGLE PHASE NOTE: The grounding method shown is one of multiple allowable methods. A GEC (grounding electrode conductor) is required only for M215-60-2LL.