What is a subpanel?

A subpanel, also called a sub-panel or auxiliary panel, is a secondary distribution center that pulls power from your main electrical panel. Rather than running all circuits back to the main panel, a subpanel sits closer to where power is needed most, then feeds multiple circuits from that remote location.

Subpanels are especially common for garages, detached workshops, accessory dwelling units, or home additions in Spartanburg homes. They reduce the need for long wire runs and let electricians install dedicated circuits for high-demand areas without crowding the main panel. A two-car garage might use a subpanel to power tools, compressors, and lighting independently. A finished basement addition can draw from a subpanel rather than stretching circuits from the main box upstairs.

Proper sizing and installation matters. A subpanel must be fed by an appropriately sized breaker in the main panel and properly grounded. The feeder wire running from the main to the subpanel has to match the breaker amperage. Many jurisdictions in the upstate require subpanels to meet the same code standards as main panels. This is why hiring a licensed electrician for subpanel work is important. An undersized subpanel or feeder wire can create fire hazards or fail to deliver reliable power when you need it.

If you're planning an addition, garage rebuild, or workshop setup, a subpanel may be the right solution to extend power safely without overloading your main service.