Home Electrical Panel Wiring Rules

Electric Code

• Every local jurisdiction has building codes for new homes, home remodels and projects that require adding to a home's electrical system. Most jurisdictions model their local codes on the National Electric Code that was developed and is maintained by the National Fire Prevention Association. The NEC and local codes include many rules about home electrical panels.

Size Matters

• As home electricity use grew, so has the size of the electrical panels required. A larger electrical system requires a larger electrical panel, usually containing more circuits. Older homes may still have 60 ampere electrical panels. As time passed, the trend shifted to 100 ampere services, and now in many jurisdictions, the local code specifies a 200 ampere service with a matching electrical panel be installed in new single-family homes. If your home has an older, 60 ampere service, you should upgrade it. If your home has a 100 amp service and you aren't experiencing problems such as tripped circuit breakers, you are lucky. If problems are occurring or you plan to remodel or add on to the home, consider upgrading to a 200 ampere service and electrical panel.

Circuits

• The electrical panel is where individual circuits originate. The electrical code dictates a dedicated circuit and circuit breaker for some applications, such as to your stove or air conditioner, with the size of the wire used and circuit breaker size determined by the electrical need of the appliance. Other circuits are groups of lights and outlets; for instance, all the electricity for an individual bedroom might be on one circuit. The number of circuits you can install is unlimited. The number of lights and outlets you can group together depends on how many of the lights and power outlets will be used simultaneously. It's possible to use heavier wire and a larger circuit breaker and group more lights and outlets together, but a better rule is to install another circuit breaker in the electrical panel and group fewer lights and outlets together.

Professional vs. DIY

• Basic home wiring is a skill you can learn to do safely. However, if you aren't skilled and knowledgeable, hire a licensed electrician to work on your home's electrical system or install your home's electrical panel. Not only do they follow safety rules, they also know the applicable electric code rules that need to be followed. If you are doing your own electrical work on projects requiring a building permit, you may need to hire a licensed electrician to check your work and sign off on it to fulfill the requirements of the building inspections required by the permit.