An old house can get fixed up by a lot of people over the years and not everyone does it right. One problem that often occurs is finding wires that are spliced together with wire nuts that are left exposed. Exposed connections can get broken apart and cause a fire hazard. If you are renovating an old home and find exposed wire connections, you should install an electrical junction box to hide and protect the connection. Here is how you can install an electrical box to hide and protect the wire connections.
Turn Off Power
You need to turn off the power before you start to work on the electrical connections and box. Turn the power off at the circuit breaker box and not a wall switch. Someone can come in and accidently turn on the switch while you are working and you could get hurt.
Test for Power
You need to test the wires to make sure the power is off as circuit breakers aren't always labeled correctly or at all. Carefully remove the wire nuts and any electrical tape around the ends of the wires. Do not touch the bare wires at all during this procedure even if you think the electricity is turned off.
Use a circuit tester to test for power. The circuit tester has a light on it that lights up when there is an electrical current between wires. Place one of the prongs from the circuit test to the black wire in the wire cord and the other probe on the white wire. The black wire is used to carry the full voltage of electricity while the white wire is neutral and doesn't carry a voltage. If the light brightens on the circuit tester, the wires are still live and you need to shut off other circuit breakers until the light doesn't come on.
Prepare Electrical Box
There are knock-out tabs on the side of the electrical box. These tabs are used to slide the two electrical cords into the box so you can connect together the wires in the cords. Push out the knock-out tabs with a screwdriver and a hammer. You need to remove one knock- out tab on both sides of the box.
Find a stud in the wall or a joist in the ceiling and screw the electrical box to it. This will secure the box and makes sure it won't fall down.
You need to put cable clamps on both cords going into the box. The cable clamps will make sure the cords don't come loose and slide out of the box. The clamps are round and will slide easily onto the cords. You tighten the clamps with a flathead screwdriver. Be careful not to over tighten the clamps as they can dig into the cords and wires and cause a short.
Slide the electrical cords through the knockout tab holes. Screw the locknuts onto the threaded end of the clamps and tighten it. You tighten it locknuts by pushing the lugs on the locknut clockwise with a flathead screwdriver. The cords and wires are now secured to the box.
Use new wire nuts to connect the wires together from the two cords. Connect the wire according to their color. White is connected to white, black is connected to black, and the copper ground wires are connected together.
Screw-on Cover Plate
Place the cover plate for the electrical box over the opening on the box and screw it on to cover the wires connections. You can turn the power back on.
Contact an electrician for more advice.