A NEMA 6-15 plug has two horizontally-aligned straight-blade prongs and one horseshoe-shaped prong. A 6-15 plug's prong shape and spacing only fits into a NEMA 6-15 receptacle. The horseshoe-shaped prong pushes into the receptacle's ground terminal and the 6-15's horizontal prongs slide into the receptacle's hot slots. A NEMA 6-15 plug, considered a 15-amp 250-volt 2-pole 3-wire grounded plug, often supplies electricity to window-mounted air conditioners and some commercial office equipment. A NEMA 6-15 plug usually connects to its electrical device with 14-gauge wires.

Step 1

Remove the last 3/8 inch of the insulation from the end of each wire entering the NEMA 6-15 plug with wire strippers. Some wire sets use three insulated wires — usually black, white and green colored — and some use two insulated wires — usually white and black colored — with an additional uninsulated wire.

Step 2

Grip the middle of the stripped portion of each wire with a pair of pliers. Form the end of the wire into a hook shape.

Step 3

Loosen the three NEMA 6-15 plug's wire terminal screws with a Phillips screwdriver. A NEMA 6-15 plug uses a green screw and the letter "G," found stamped into the plug's body, to identify the ground terminal. The two unlabeled wire terminals connect to the live wires.

Step 4

Slip the ground wire's hook over the NEMA 6-15 plug's ground terminal screw, then tighten the terminal screw. The ground wire, the green or uninsulated wire, protects the appliance's user from accidental electrocution.

Step 5

Slip one of the hot wire's hooks over one of the NEMA 6-15 plug's hot terminal screws. Tighten the 6-15 plug's terminal screw. The two interchangeable hot wires in a 2-wire 250-volt electric circuit usually use black and white insulation, but sometimes use black and red insulation instead.

Step 6

Slip the remaining hot wire over the last NEMA 6-15 plug's terminal. Tighten the 6-15 plug's terminal screw.