How to add a circuit to an electrical panel
When a circuit becomes overloaded due to excess use or you need an extra circuit for new electrical items you will need to add a circuit to your electrical panel. Adding a circuit to a panel requires adding a new circuit breaker.
Electrical work should always be done by someone that is familiar with the work. Shutting the power off at the disconnect before beginning to work on an electrical panel is highly advised.
Determine if there is space and load capability.
Before adding a new circuit in an electrical panel you must be sure there is space available and that an additional circuit will not overload the panel.
Household electrical panels normally range from 100 to 200 amps. Individual circuits and the panel itself are designed to be operated at 80 % of load rating. A 100 amp panel should not have a load of greater than 80 amps at any one time. A 20 amp circuit should not have a load of greater than 16 amps at one time.
Obtain the correct breaker:
Circuit breakers and designed to fit in specific panels. A Siemens panel should use a Siemens breaker. A Square D panel needs a Square D breaker. Also get the amperage required. Common household circuits are 15 and 20 amp with air conditioning, electric ovens and other equipment requiring more. Breakers may also snap in or bolt in with a screw so the exact kind does matter.
Installing the new breaker:
Use a Hot Stick or meter to be sure there is no power to the panel. There will be power going INTO the main breaker but there should not be any coming out.
The new breaker will either snap into place or bolt in with a screw. Make sure it is seated firmly in place. At this point in the process new circuit wires would be added. This is not covered in this guide.
Remove the knock out in the panel cover:
In order to replace the cover the knock out corresponding to the new circuit breaker will need to be removed. Bend this piece back and forth until it snaps out. Pliers can be used to assist in this.
Replace the panel cover:
Position the panel cover carefully and reinstall the four screws that hold it in place.
Label the new circuit if wires have been added.
Turn the power back on at the main breaker.