Main Breaker Panel Vs Main Lug

Main lugs load centers are sometimes called sub or sub feed panels.

Main breaker panel vs main lug.

Main lug load centers are sometimes referred to as add on. Main lug only panels are typically applied downstream of a main circuit breaker panel and are often referred to as secondary or add on panels. A main breaker panel mcb has a main breaker built into it. For mlo panels the incoming cables are terminated on line side lugs that are attached directly to the bus no main overcurrent device exists in the panel.

There are situations where a back fed circuit breaker and a retainer clip required by nec are used to convert a main lug load center to a main breaker load center. If you attach to lugs in the main box then you need to have a main breaker in the sub panel. You should only have one main panel. If the panel was designed to be a main panel there would be a lug that connects the neutral ground bus to the panel.

They are sometimes installed adjacent to a main panel to provide additional circuits when the main breaker panel is full or they may be installed far away from the main panel to provide a local disconnection for circuits in a detached building garage or room addition. If you use a main lug panel you need to have a back fed breaker as a disconnect or have no more than 6 breaker throws handles. You can convert any panel to a subpanel by simply adding a ground bus and moving all the grounds to the added bus. A mcb panel is used when there is only a meter just outside and this feeder cable or conduit does not exceed 10 feet from meter to panel.

You need to remove that lug if converting to a subpanel. A main lug only mlo panel only has main lugs and is intended to be fed by a main breaker upstream. Buy a 100 amp main breaker contractors pack at a big box cheapest way to go. You can feed it with less than 100 amps sent from my rct6203w46 using tapatalk.

Main lug units are primarily used as a distribution panel where there is a main breaker upstream in the system.