Electrical power lines are used to supply current to virtually all homes. One hot 120-volt power line connects to the left bank of the main panel, and another 120-volt to the right bank. Each bank is insulated from the other. Double-pole circuit breakers combine the two banks to provide 240-volt power for electric stoves and clothes dryers, while single-pole breakers use power from one bank only. A ground line is included with the two power lines and also connects to the electrical panel.
Things You'll Need
Wire stripping pliers
Notify your local electric company. Inform them of the work being done and have them disconnect the power to the house.
Check the terminals at the electric meter with a voltage tester to ensure no power is present. Place one tester probe on the left terminal clamp and one probe on the center neutral terminal clamp to perform the test. Hold the neutral or ground clamp probe in place, and move the other from the left terminal clamp to the right terminal clamp, to complete test.
Strip 3/4-inches of insulation from each of the two power lines and the neutral or ground line at the meter end and the main panel end, using the wire stripping pliers.
Identify the neutral or ground line. It is made conspicuous by either a white linear stripe along its insulation, or by a band of white tape.
Connect the neutral or ground line to the neutral buss bar terminal clamp in the main panel. Insert the stripped end of the line into the clamp and tighten the terminal clamp screw clockwise, with a flat-head screwdriver. Ensure the line is fully seated and tightly clamped in place.
Connect the two black power lines to each of the two terminal clamps in the main panel using the screwdriver. Ensure both lines are fully seated and tightly clamped.
Connect the neutral or ground line to the neutral or ground terminal clamp in the meter box. It is located in the center of the box, with the power line terminals on either side of it. Insert the wire into the clamp and tighten the terminal screw with a screwdriver.
Connect the two black power lines to each of the two terminal clamps in the meter box using the screwdriver. Ensure both lines are fully seated and tight.
Re-tighten all the terminal screws in both panels. Secure, tight connections ensure that no arcing of electricity will occur.
Contact the power company to restore power and install the electric meter.
Some terminal clamps are secured with hexagon lugs rather than slotted screws. If your main panel or meter box uses hexagon lugs, a hex wrench must be used to tighten the terminal clamps.