Connecting a New Circuit to Your Home or Shed
Once you’ve found an area that is close to where you want to run a new circuit, you will need to calculate the existing load. For good measure you don’t want to exceed its load capacity by roughly 75%. You also can’t have more than 8 devices on one circuit per 20 amp breaker.
To calculate how many devices and its load on a circuit, turn off the breaker for that particular circuit you want to tap into. Plug a working lamp into outlets and turn on switches to find out which are off and on. Add the wattage ratings of all the devices hooked to the circuit and those that you are going to install. Divide the total watts by 120 volts. The number you get shouldn’t exceed the amps on the circuit breaker by 75%. Overloading a circuit is a good way to burn up your home or making devices overload and circuit failure to occur.
Joining into an end of the run outlet is an easy way to add a new circuit. This means an outlet with one cable going into it. If it has two cables going into it, it is a middle of the run circuit. I will explain how to connect a circuit to that next. First, add your new cable to the box and run it to were ever your new device will be at. On the outlet, there are screws on the side. This is where you will attach the new wires. The brass screw is for the hot or black wire. The silver screw is for the white neutral wire. The bare wires are ground and will be wire nutted together or if it is a metal box will be grounded with a jumper wire to the box. Connect all the wires accordingly. Always hook the wire around the screws clockwise and tighten the screw. Make sure the wire goes around the screw at least ¾ of the way around.
Joining a middle of the run circuit is more difficult. You need to decide if you can fit all of the wires in the box before you begin. If it is not, find another spot to connect the new circuit. You will connect the wires the same way as an end of the run circuit, but you will need to add a jumper wire to each and a wire nut. A jumper wire is a 6 inch wire that comes out of a wire nut with the other wires in the circuit. Cut 6 inch wires of the same color. Attach all the wires together with a pair of lineman’s pliers and twist clockwise. Attach a wire nut firmly so that no bare copper is exposed. Now take the jumper wire and attach it to the screw on the outlet as outlined above.
Place all of the wires back into the box and re-attach the outlet. With a circuit tester, insert the probes to see if the circuit is complete. Don’t turn the power on until you have done this step first. If the circuit is complete you are then ready to connect the new device to the new circuit.
Remember to always shut off power from the breaker and test it to make sure it is not hot. Always wear gloves and use rubber coated handles on all of your tools. Electricity can be easy to work with if you’re careful. Enjoy your new circuit!
