Many homes in Boise, Idaho have in-law units or other accessory dwelling units that are used as home offices, fitness rooms, theater rooms, and more. In these environments, having electrical sub-panels installed is important for a variety of reasons. Read on to find out what residential electrical sub-panels are and why they matter.

What Is a Residential Electrical Sub-Panel?

The main circuit breaker box or the main sub-panel in your home is the heart of your electrical system. This is where power enters your home from your utility company and gets distributed to individual branch circuits. The circuit breaker box prevents electrical overload and disrupts the power supply when various hazards exist. To resolve tripped circuits, you have to physically visit this main breaker box and reset them as needed. This can prove problematic in larger homes and buildings with separate dwellings. For instance, if you have an in-law unit that you’re renting out, everyone in the building might be using the same panel for all of their electricity needs.

Residential electrical sub-panels solve this and many other problems. They don’t add more power to homes. Instead, they divide the existing power supplies up so that circuits for separate areas can be controlled individually. You might add a sub-panel to an attached rental unit so that your tenants don’t have to bother you every time they trip a circuit. A sub-panel acts as a satellite circuit breaker panel.

The Basic Structure of an Electrical Sub-Panel

Although slightly smaller, residential electrical sub-panels look a lot like main circuit breaker boxes. They have circuit breakers and bus boxes that are fed by the main feeder wire and branch wire circuits that originate at the main breaker box. The 240-volt double-pole breaker wire that travels from the main breaker to the sub-panel is split into individual branch circuits that control each electrical service area. A sub-panel covers the electrical supply for a limited amount of space. For instance, you might install a sub-panel for your home theater, finished basement, attic bedroom, or garage just as you might install one for an in-law unit.

Like main circuit breaker boxes, electrical sub-panels are subject to local building codes and the National Electric Code (NEC). These units must have a minimum amount of clearance around their perimeter. Thus, they cannot be installed too close to the ceiling or floor, too near adjacent walls, or too close to in-wall electrical features. Per the NEC, residential electrical sub-panels require at least 30 inches of clearance across their faces, and they must be installed at least 78 inches above the flooring.

Electrical Sub-Panels and Electrical Metering

When using a residential sub-panel to accommodate tenants in an accessory dwelling unit, you’ll solve the problem of accessibility, but you won’t separate your electrical metering. Sub-panels are fed from the main breaker, and electrical metering remains unchanged by these installations. To accurately measure the amount of energy that your tenants are using for billing purposes, you’ll need to supplement your sub-panel by having a residential sub-unit tenant meter put in as well.

When Is Having an Electrical Sub-Panel Installed a Good Idea

Accommodating in-laws or tenants is hardly the only reason to have a sub-panel installed. If you’re in the process of updating your home’s electrical system, you may need to add new circuits. This is a common need in older and historic Boise properties that were built to handle the comparatively modest energy demands of decades past. An older main breaker might not have sufficient space for new circuits. In this case, a sub-panel can be used to branch out the main power supply and put the new circuit breakers in another area.

One of the greatest benefits of performing electrical upgrades like this is being able to locate sub-panels in areas that are convenient to specific service locations. For example, if you’re installing an in-floor wine cooler in your basement or kitchen, connecting this to an electrical sub-panel will limit how far you have to walk when circuits need to be reset. This also makes it easier for homeowners to avoid circuit overloads in areas where new appliances are often added.

Limit Wire Routing With Residential Electrical Sub-Panels

If you’re renovating or remodeling your home, having one or more electrical sub-panels put in can limit the need for invasive wire routing projects. Routing a single 240-volt double-pole breaker wire from the main panel to a sub-panel could prove a lot easier than routing new circuits to your current main breaker. It can also prove a lot less invasive and far more cost-effective overall.

In Larger Homes, Electrical Sub-Panels Offer Convenience

If you have a large, multistory home, having a single electrical panel can be incredibly inconvenient when circuits trip. If a circuit breaker trips in one area, you might need to walk to the other side of the building or travel down several flights of stairs to reset it. Even without the need to add additional circuits and deal with the resulting space constraints, having one or more sub-panels put in can be very beneficial. This is especially true in households with aging adults and other residents experiencing mobility challenges. As an example, if your aging parent has moved into your downstairs bedroom, they shouldn’t have to travel upstairs to reset a circuit. However, on a 200-amp service, it’s only possible to install two to three sub-panels in total. In bigger properties with complex layouts, other strategies for increasing convenience may be required instead.

Electrical Sub-Panels Aren’t the Answer to All Electrical Problems

Although they’re quite handy for dividing up the electrical service in shared buildings, limiting runs to remote breaker boxes, and establishing separate utility services, residential sub-panels aren’t capable of solving all electrical problems. Given that they merely divide up the power supply from the main breaker, they won’t single-handedly resolve excess energy demand.

In some instances, installing residential electric sub-panels can limit the load on main breaker boxes and prevent frequently tripped circuits. However, other causes for tripped circuits should be investigated before choosing a sub-panel as the solution. A circuit that’s overloaded at the main breaker will still be overloaded at the sub-panel if the service area or service load isn’t currently split.

Installing sub-panels is not an alternative to upgrading an outdated electrical panel. Electrical panel upgrades should be performed once every 15 to 20 years or whenever there’s a substantial increase in household energy demand. These improvements have no impact on malfunctioning, non-functioning, or underperforming outlets and light switches, and they won’t resolve problems with power surges or mini-power surges. If your electrical panel feels warm or if your outlets are hot to the touch, have singe marks, or have a sweet, burnt odor, you need electrical repairs.

We are committed to helping residents of Boise, Idaho update, maintain, and refine their electrical systems. Since 1925, we’ve been providing first-rate HVAC, plumbing, and electrical services. We also offer sump pumps, water filtration, lighting, ceiling fans, and more. If you’re interested in installing an electrical sub-panel in your home, give AJ Danboise Plumbing, Heating, Cooling & Electrical a call today.

company icon