How to Wire a NEMA L6-30R | eHow How to Wire a NEMA L6-30R. The NEMA L6-30R is one of the receptacles approved by the National Electrical Manufacturers Association in the U.S. This type of female plug is a two-pole, three-wire, 250-volt, 30-amp locking receptacle. It has two hot wires and one ground wire; it is designed to lock onto a NEMA L6-30P male plug by twisting the plug..[PDF] Wiring Device NEMA Wiring - AutomationDirect 6-15R 6-20R6 -30R 6-50R L6-15R L6-20R L6-30R 208V or 250V EQUIP. GR. G 7-15R 7-20R 7-30R7 -50RL 7-15RL 7-20R L7-30R 277V AC EQUIP. GR. G W SYS. GR. 2-Pole 2-Wire 2-Pole 3-Wire Grounding 125V 208V or 250V 125V 208V or 250V 277V AC Reference material only. Please see Wiring Section in the catalog for product part number.