WHEN IS IT TIME FOR AN ELECTRICAL SERVICE PANEL UPGRADE?
In this article, we'll talk a little bit about the purpose of your home's electrical panel(s), electrical service size, how to determine whether or not your home's electrical system is functioning properly, and whether or not it's time for an upgrade.
Let's get started by defining "electrical service size" and briefly discussing your electrical service panel, two different components of your home's electrical system that work together to provide safe and efficient electrical service distribution throughout the home.
Electrical Service Size
The electrical service size of your home is the capacity, in amps, of the electrical service in your home, and determines how many appliances and electrical devices you're able to operate at the same time. Simply put, the electrical service capacity, or service size, is determined by the smallest capacity of three primary electrical components: the service entry cable feeding the home from the electrical company, the main electrical service panel, and the main electrical service disconnect. In a properly designed electrical distribution system, all three of these components will be identically sized. Particularly in the case of older homes or homes that have had piecemeal upgrades performed over time, this is not always the case, and the electrical service size will be limited by the weakest link, so to speak. Typically, homes will have a service size of between 100 and 200 amps, though 60 amp electrical size was once quite common.
Electrical Service Panel
The importance of your home's main electrical service panel cannot be overstated. In fact, it is the single most important piece of electrical equipment inside your home, responsible for taking power from the electric company's service drop and distributing it to the power outlets throughout the home. A properly functioning service panel is critical to maintaining an efficient, safe home electrical system. An electrical service panel, also known as the "breaker box", accepts power from the electric company's service entry cable into a main breaker. Individual circuits breakers within the electrical service panel are then wired to individual circuits distributing power throughout the home. These individual circuit breakers are sized between 15 and 200 amps. Optimally, circuits supplying lighting fixtures would be 15 amps, circuits supplying power outlets would be 20 amps, and circuits supplying major appliances would typically be rated at between 30 amps and 60 amps. The largest circuit breakers, rated at 60 amps and above, would usually be used to supply separate electrical service to subpanel in a garage or other area requiring multiple circuits of its own.
Fuses and fuse panel replacement
Most homes built before about 1960 used fuses and fuse panels, rather than circuit breakers and service panels, to distribute electricity throughout the home. While fuses and fuse panels themselves are not necessarily dangerous, it is dangerous to supply electricity to a circuit with a fuse of a size different from the size of the circuit's wire. In the past, when fuses would go bad, homeowners would often replace the fuse with a higher-rated fuse in the hopes of more capably managing the load on the circuit the fuse was responsible for protecting. Unfortunately, an incorrectly sized fuse will allow too much current to flow through a wire designed and rated for a lower load. When this happens, the wire will get hot, overheating and potentially causing an electrical fire. With circuit breakers and electrical service panels, the risk was mitigated by the breakers and circuits being more difficult to change, causing more homeowners to properly resort to hiring a licensed electrician to perform the work. This dramatically reduced the risk of electrical fires throughout the nation, and today circuit breakers are the absolute standard for any new electrical installations. Fuses and fuses panels are now considered to be enough of a risk that they should certainly be replaced in all home installations. In fact, many insurance companies and banks will deny coverage and loans on home with fuses and fuse panels.
Electrical service panel in a state of disrepair
While electrical service panels are generally very reliable, they can certainly become damaged over a period of time. Not surprisingly, water infiltration caused by plumbing leaks or acts of nature are catastrophic for electrical service panels, causing electrical shorts and potential corrosion of the panel's metal components. Corrosion is often a cause of higher electrical resistance, creating areas capable of overheating and causing electrical fires, while electrical shorts themselves are significant fire hazards. Circuit breakers within the panel may also cease functioning properly, losing their ability to trip in the event of an overload or short. When this happens, the electrical wiring is no longer protected, becomes hot, and likewise creates an electrical fire hazard. Improperly sized circuits can also be an issue, causing similar overheating conditions when, for example, a higher capacity circuit breaker has been installed in a lower capacity circuit. As in the case of fuses and fuse panels, banks and insurance companies rely on an inspector to determine their risk when insuring or providing home loans, and any of the above conditions will likely cause a home to fail inspection.