October 02, 2016
Adding And Installing A Subpanel
Importance Of Electric Subpanel For Homeowners
In essence, an electrical subpanel can be thought of as a mini service panel. Its basic structure is the same as a service panel, with a main feeder wire leading into bus bars and circuit breakers. Branch wire circuits lead off of the circuit breakers into various parts of the house.
Installing or Adding A Sub-panel to your home.
How to Add a Subpanel
Check with your city’s building and codes department to see if you need to acquire a permit before you begin the work. Minor electrical changes generally do not need a permit, but each jurisdiction varies. In some areas, permitting is required for any type of Electrical work, no matter the size in scope or significance. This work, however, would by no means ever be considered “minor”.
- When you meet with the building code representative, ask about the inspection schedule so you know when to call for a rough inspection as well as a final inspection. Many localities have part-time inspectors, so if you’re on a schedule you should discuss it with them first.
Find a good light source that can run off a battery or generator. You will need light to work on your project after you shut off the electrical power to the building.
Determine where you will mount the sub panel. If space is an issue, you don’t need to install it next to the main panel. However, you must be able run wire through to that area. Keep in mind that a closet is not an acceptable location for a panel. The area 3 feet (0.9 m) in front of and above and below the the panel should be clear from the floor to the ceiling.
- If you install your sub panel closer to the rooms you are adding power to, you will use more of the larger sub-feed cable between the two panels; but fewer smaller wires to the outlets than if you installed the sub panel close to the main panel.
Remove the lowest amp rated double pole circuit breaker or 2 low rated single pole circuit breakers from the main panel to make room for the new double pole circuit breaker that will supply the new sub panel. The 2 circuits you removed will need to be re-fed from the new sub panel. If the sub panel is the same brand, you might be able to reinstall the original circuit breakers in it to re-feed those 2 circuits.
- If you have breakers terminal screws that are serving more than one conductor, called double-lugging; consider moving circuits to the sub panel so that none are double-lugged – or combine the them with a short length of the same size wire (called a “pigtail”) in a wirenut and use the pigtail to feed them.
How Do You Add A Subpanel To An Existing Breaker Panel?
Route in the subpanel feeder cable, and remove any neutral bonding jumpers to ensure that ground and neutral are only connected at the main panel. Join the branch circuit wires, and install the new breakers. To finish the job, fasten the door to the subpanel, and turn the main panel’s sub-feed breaker on. Turn on the main panel’s main breaker and the subpanel’s main breaker. Double-check that the circuits are working, and update the labels on both panels.