The main electrical panel in a house receives its power directly from the electric meter through two 120-volt hot wires and a neutral. The main electrical panel's ground source comes from a solid copper rod driven into the soil below the panel. The main electrical panel contains the home's main circuit breaker, and sometimes the circuit breaker for the pool pump and the air-conditioning system's condensing unit. Turning off the main circuit breaker disconnects the electricity to every electrical circuit in the house.
Things You'll Need
- Utility knife
- Wire strippers
- Anti-oxidizing compound
- Allen wrench
- Slotted screwdriver
Ask the electric company to turn off the electricity to the electric meter. Never open a home's main electric panel with the power turned on.
Inspect and understand the main electric panel's wire connections, using the terminal chart as a guide. Notice the supply-voltage lugs, the neutral bus bar and the bus bars for the outgoing circuit breakers.
Remove 1/2-inch of the insulation from the ends of the braided wires in the main electrical panel with a utility knife and from the ends of the solid wires with either the utility knife or wire strippers. The heavy-gauge wires contain a braided aluminum core. The wires supplying power to the pool pump's motor and the condensing unit, if equipped, have a solid copper core.
Coat the ends of each wire containing an aluminum core with an anti-oxidizing compound.
Insert the end of the neutral wire from the electric meter into the large lug on the main electrical panel's neutral bus bar and tighten the lug's retaining screw with the correct Allen wrench. The neutral wire either does not use insulation or has insulation with an easily identifiable marking. The main electric panel's neutral bus bar mounts to the panel's housing.
Slip the sub-panel's neutral wire into the neutral bus bar and tighten the retaining screw. The sub-panel's neutral wire uses an easily identifiable marking, usually either white insulation or black insulation with bands of colored tape.
Slide the ends of all of the bare copper wires into the neutral bus bar and tighten the retaining screws with a slotted screwdriver. The thick copper wire in the main electrical panel connects to the ground rod and the thin copper wires connect to the branch circuits.
Connect the 120-volt feeder wires from the electric meter into the main electric panel's supply-voltage lugs. Tighten the lugs' retaining screws with the Allen wrench. Each lug receives one wire from the electric meter.
Place the ends of the branch circuit's hot wires into the appropriate circuit breaker. Tighten the circuit breaker's retaining screws with a slotted screwdriver. Install the circuit breakers in the main electric panel, with the main circuit breaker on top and the other branch circuit breakers near the bottom of the panel.
Tips & Warnings
- Many local building codes require a building permit and that a certified electrician inspect the main electrical panel for code compliance before turning on the electricity to the home.
- Photo Credit Jupiterimages/liquidlibrary/Getty Images
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