Installing Electrical Junction Box in Homes

An electrical junction box is an enclosure that is mounted mostly on the wall in buildings; it protects the wiring connections of the building from damage and prevents electrical hazards. A junction box is often used to create branches of electrical circuits in different directions from the main point.

Right Junction Box, Right Location

Knowing the right electrical junction box to use at a particular location is very important. When installing a junction box outdoors, you need to get a waterproof electrical unction box with gaskets to prevent water from entering it. And make sure the junction box is large enough for the number of wiring connections you will be making. For example, the smallest 2-by-4-by-1-1/2-inch deep box can comfortably splice only two cables (four or five conducting wires), while the largest 4-by-4-by-2-1/8 -inch-deep boxes can handle as many as four to six cables.

All power sources should be turned off to prevent electrical hazards, confirm that the wires you are working on have no electricity running through them by tasting them with a tester.

Mount the box in the position you want it to be, and make sure you separate the circuit wires before mounting the box. If you are installing a metal box, always remove the knockout on the box first before you do anything.

The electrical wires should be properly secured with clamps in the junction box. Secure the wires by screwing in the clamps to make them tight.

Join the wires with the approved wire connectors, the ground wires should be joined first, and if the electrical junction box is metal then you need to use a pigtail to prevent contact with metal.

Join the neutral wire together, and then join the hot (black) Wires together also.

Finish the job by carefully folding the wires into the box, installing the box cover, and screwing it in. Restore power to the circuit by switching the power source in the building.

For more information or assistance during normal business hours, call or e-mail TPS at the phone number above. You can also complete and submit our Service Project Inquiry form.