Electrical upgrades are rarely one of the first things that most homeowners consider when remodeling or putting an addition onto their home. Modern electrical systems are reliable and robust, which means that it often seems unnecessary to perform major upgrades. While this is generally true, an upgrade is worth considering any time you are changing or adding new branch circuits to your home. A common way to upgrade electrical service is to add a new subpanel.
What Is a Subpanel?
The purpose of your home's main electrical panel is to distribute the mains electricity entering your house into individual branch circuits. Depending on the design of your home's electrical system, each branch may supply power to one or more rooms. In some cases, a branch may be dedicated to a single appliance as well. Each of the branch circuits has its own circuit breaker within the main electrical panel. A subpanel is simply a smaller "child" service panel which branches from the main panel and provides a single point of origin for multiple branch circuits.
Note that subpanels are still part of the home's main electrical system. The subpanel is fed by a circuit in the main panel, so metering for branch circuits that originate with the subpanel is still on the home's main circuit. For separate metering (such as might be desirable for rental units), additional steps are necessary. Instead, subpanels are typically used in a few different scenarios for single-family homes.
Additions May Require a New Subpanel
It is typical to install a subpanel for an addition if there is no longer physical space available in the main panel for the new branch circuits. Replacing the main service panel can be a significantly more expensive and disruptive job than simply adding a new subpanel, so this upgrade commonly allows homeowners to save some money. Although adding additional branch circuits to the main panel is still preferable if possible, the use of a subpanel does allow the addition's electrical circuits to be cleanly separated from those used for the rest of the house.
Separate Areas May Not Have Access to the Main Panel
Although subpanels alone are not sufficient to separate your electrical needs for a rental unit, there may be situations where accessing the main panel is difficult. One example would be if your home includes an in-law apartment or other separate living space that is still billed with your home's regular electrical service. In these cases, a subpanel inside the separate living space makes sense so that its occupant does not need to have access to the main panel in the event that a breaker trips. Adding a subpanel in this situation also makes it significantly easier to add separately metered service later should you decide to use the extra space as a rental unit.
Subpanels Can Reduce Overcrowding in the Main Panel
Finally, subpanels are sometimes added as a way to deal with an overcrowded main service panel. Overcrowding is not necessarily a hazard in and of itself, but too many branch circuits on a single panel may sometimes create a hazard or a local code violation. These issues are usually discovered by electricians when performing some other service on the panel, and the addition of a subpanel can be a cost-effective way to mitigate the problem. By moving one or more of the existing branch circuits to a subpanel, the wiring in the main panel can be cleaned up and brought back into code.
Contact your local panel service upgrades team to learn more.