What Is a Main Lug Load Center?

The main lug load center is a way to distribute power from the main circuit breaker downstream from the main breaker.  For this reason, they are often referred to as downstream, secondary,  or add-on panels. There are ways to convert a main lug load center into a breaker box, but in general the standard main load lug center does not have the applicable back-ups to be called a circuit breaker. 

A main load lug center is used to supply a source which is added onto a house or existing breaker. Apartment complex meters or workshops often have main load lug centers so that large power sources can be readily distributed from the central breaker but do not need the security measure of voltage cut off.

Incoming power cables are fed directly into the main lugs or the bus bars. There is no primary overload protection supplied as a standard part of the main lug load center. This is the main difference between a main load lug center and a breaker. By adding a back fed circuit breaker and a retainer clip the main load lug center can be converted to a breaker box if needed.