Home Restoration and Service Panels: What You Need to Know

Editor's Note: This is article 3 of 8 in Chapter 7: The Electrical Guide of Old House Web's Home Restoration Guide. This guide was developed and edited for old homes from original materials in the U.S. Housing and Urban Development (HUD) Rehab guide.

3. SERVICE PANELS

Section 1--The Basics

The service panel in a home serves two very important functions. First, it serves as a master switch that can cut off all power to the home in an instant if necessary. It also serves as the Grand Central Station of your wiring, safely distributing power throughout a residence. Each circuit is meant to cut power immediately in the event of an overload, thus helping to avoid the risk of fire or serious damage.

The circuits are protected by either fuses or breakers. Fuses cut the power to the house when the fusible link inside them melts, opening up the circuit. Plug fuses are the most popular kind of fuse, while cartridge fuses are no longer widely used, but might be found in an old house. Breakers work with the help of a bimetal strip that heats up, bends, and trips the breaker. In high overload situations, and electromagnet pulls the bimetal strip, resulting in an almost instantaneous trip of the breaker.

Another important part of your electrical system is the ground fault circuit interrupter. A GFCI breaker or receptacle is typically used in areas where moisture can be an issue, such as kitchens, bathrooms, garages, basements, crawlspaces, and outside outlets. The GFCI can shut off the power to the outlet in 1/30 of a second if necessary.

Section 2--Repairing and Replacing Service Panels

Making certain your service panels are upgraded to meet today's recommendations and code requirements is an important part of home restoration and preservation. Just because an electrical system is old does not mean it is hazardous; however, if the electricity load required exceeds that of what your service panel can handle, replacement or upgrades will be required.

But the capacity of the service panel is not the only reason it might need to be replaced. Corrosion indicates rain water has entered the panel, probably by traveling along the service entrance cable. Corrosion can also be caused by service in a damp area. That corrosion can decrease the effectiveness of circuit breakers by increasing the amount of current necessary to trip the breaker, leading to a potential fire hazard. Loose fuses and connections can also be culprits in service panel problems.

When it's time to upgrade or replace your existing electrical service, there are several options available.

1. Installing a new panel. If the existing panel is overloaded, consider replacing it with a panel of greater capacity. An electrical construction permit is required to make this change, and the power company has to be made aware of the work. When you install a larger panel, the electric meter and related components need to be upgraded as well.
2. Home automation panels. When you upgrade to a larger panel, consider using a home automation panel. This panel allows more control over energy usage, as well as streamlining several options for your old house, such as security lights and communication devices.
3. Same capacity panel but more circuits. If your panel is not fully loaded with circuits, it is possible to simply replace the panel with a new one of the same size. This eliminates the need for an electrical construction permit.
4. Installing a subpanel. A subpanel placed next to the main panel can offer more circuits without the hassle of replacing the original panel with a larger one. This is also used when bringing electricity to another structure on the property, such as a garage or guest house.
5. Installing half-sized or dual breakers. If the existing panel has space for dual or half-sized breakers, you can take advantage of that option when adding new outlets to areas of the house that need more power, such as the kitchen or office area.
6. Type-S adapters for fuses. Due to the shape and interchangeable nature of Edison-base fuses, homeowners may inadvertently use a 30-amp fuse in a 15-amp outlet. This presents a fire hazard that can be corrected with the use of Type-S fuses. These fuses can ensure that the right size of fuse is used in your panel.
7. Ground fault circuit interrupters. The use of GFCI circuit breakers could save a life. When handling home restoration or preservation, be safe rather than sorry, and spend the extra money to install safer GFCI breakers.
8. Arc fault circuit interrupters. In 2001, the National Electric Code (NEC) began requiring that all bedrooms be protected by AFCIs. These breakers provide excellent protection against fires, especially in an old house where the overall composition of the wiring is uncertain.

While some upgrades to your electrical system such as AFCIs or GFCIs are more expensive than standard breakers, they added protection is invaluable. The electrical system is one area in your old home where safety should always come first.