How to Install a New Basement Circuit

Master electrician Heath Eastman solves a homeowner’s breaker problem by installing a new basement circuit.

by Heath Eastman

Master electrician Heath Eastman takes us on a house call to help solve a problem with a tripping breaker. Heath investigates and finds that the circuit has undersized wiring and power cords, and should be on its own breaker. He then installs a new 20-amp breaker and outlet in the basement to solve the issue.

If appliances in the basement are tripping breakers throughout the rest of the home, there might be an issue with circuits. And the solution might be to install a new breaker, wiring, and outlets. Here’s how to do that.

How to Install a New Basement Circuit

If an existing device (or outlet) needs to be removed from the circuit, shut off the breaker. Test the device with the electrical tester to ensure that there isn’t any power on the outlet.
Track the existing device’s wiring back to a junction box and test the wires in the circuit with a voltage tester to ensure that nothing is live in the box. Disconnect the existing device’s wires from the wire nuts to remove it from the circuit. Reinstall the wire nuts and close up the junction box. Then, remove the existing outlet if necessary.
If installing a new junction box, find a suitable location. Place the outlet against the wall and mark the screw locations. Use the hammer drill and masonry bits to drill into the block wall, and use masonry screws to fasten it. Choose a knockout hole, tap it open, and install a cable clamp.
If necessary, install running boards across the floor joists overhead from the outlet’s location back to the electrical panel. It’s best to make the run as straight as possible.
Run wire from the new outlet’s location to the electrical panel. Run it straight up from the box and down the length of the running board. Staple the wire in place on the board loosely in a few spots to keep it up and out of the way.
Shut off the main breaker to the panel, remove the panel cover, and test the wires below the breaker to ensure that the panel is dead.
Choose a location for the new breaker and find a knockout on the side of the panel box that makes the most sense. Tap the knockout hole open and insert a cable clamp in the hole. Run the wire through the panel, leaving the end long.
Install the new breaker by fitting the hooks in the panel over the tab on the breaker. Once hooked, press down firmly on the breaker to clip it into place on the main bus bar. Extend the pigtail wire and attach it to the neutral bar.
Cut and strip the wire to length at the panel. Attach the black wire to the breaker, the neutral wire to the neutral bar, and the green wire to the grounding bar.
Cut the wire to length at the outlet side. Leave it around 12 inches long. Slide the end of the wire through the cable clamp, strip the jacket, and strip the ends of the individual wires.
Bend the ends of the wires into small hooks. Place the black wire over the new outlet’s gold screw, the white wire over the silver screw, and the green wire over the green screw. Tighten all the screws before wrapping the outlet with electrical tape and installing the outlet in the junction box.
Finish securing the wire to the running boards with wire staples.
With everything secure, reinstall the panel cover. Shut off all the individual breakers, flip on the main breaker, and then re-energize each breaker one at a time. Test the new outlet with a pen tester before installing an outlet cover.

Resources

Heath identifies why a homeowner’s breaker trips when the dehumidifier is running. After, Heath installs a new basement circuit into the receptacle.

Heath uses an electrical outlet tester to see if the existing outlet has ground going to it.

Heath uses a drill and pilot drill bit to create a pilot hole in the stone foundation. He then installs a new work metal electrical box using screws. Heath then uses a cordless jigsaw and 1/2-inch offset bender for the conduit pipe.

Heath then runs a 12-gauge wire from the new electrical box over to the electrical panel. He secures the wire to the joists overhead using a crown stapler and electrical staples.

Heath replaces one of the fillers on the circuit breaker with an arc-fault circuit interrupter (AFCI) breaker, which is now required by code in Massachusetts whenever a receptacle is replaced.

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