A Subpanel is a Secondary Breaker Box
Instead of originating at the main service panel, electrical circuits can begin at a nearby subpanel that is powered from the main panel through one heavy-gauge cable. This configuration saves wiring, energy and your footsteps to a distant panel to reset a tripped breaker.
Subpanels can update old electrical systems
Adding a subpanel is sometimes the best way to integrate new wiring with an old electrical system. In the article Wiring a Master Suite Addition, a new subpanel was installed to replace an old, failing subpanel in a poor location. The article lists some other circumstances where a subpanel can save the day:
- If the main panel doesn’t have enough open breaker spaces for the new circuits
- When AFCI breakers aren’t available for an older electrical panel
- If it’s a long way from the new wiring to the main panel
- Pulling one feeder cable would be more convenient than pulling several branch-circuit cables
- If you expect to need more circuits in the same part of the house in the future
||Fitting and Fastening the Box
See how to measure and mark the location of your new subpanel, and attach it firmly to your wall.
||Running the Main Power Feed
Learn how to run the main feed cable into the box. Also, get some tips on measuring and maneuvering large-gauge cables in a tight space.
||Installing Circuits and Breakers
See how to run wires, install breakers, and make all the connections in the subpanel. Plus, learn an easy to organize and label your circuits.
||Subpanel Safety Tips (FREE)
Working in any electrical panel can be extremely dangerous. Find out what precautions to take when installing your subpanel.
VIDEO: Snake Wire With an Old Tape Measure
FURTHER RESOURCES ON FineHomebuilding.com
A tape with a missing hook is great for getting between insulation and drywall.
Ten Common Wiring Problems
Installing a Circuit Breaker in an Existing Panel
Frequently found mistakes that could cost you your house or your life used to
When adding a new circuit or replacing a faulty breaker, here is what you need to know to work safely in the panel
An Electrical Tool Kit
Essential tools and materials for the most common wiring tasks
Running New Wires through Old Walls
The Inspector Game:
With an assortment of tools, a few tricks, and a little luck, you can make electrical cable go where you didn't think it could
Inspect an Electrical Panel
Help tie up five loose ends in this sloppy electrical service installation.
Brian Walo is a licensed electrician in Mount Pleasant, SC. When he’s not designing additions or renovations, he enjoys fishing, working on handmade guitars and furniture, and honing his culinary skills. Brian lives with his wife, Val, and their daughter, Grace.
WIRING A HOUSE
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