Main Breaker Panel Vs Main Lug

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.

Main breaker panel vs main lug.

Main lugs load centers are sometimes called sub or sub feed panels. You can convert any panel to a subpanel by simply adding a ground bus and moving all the grounds to the added bus. You should only have one main panel. Main lug vs main breaker is simply a matter of whether the added panel has an integrated protection device.

If you attach in your main box to a breaker then it can serve as the protection device for the sub but doesn t have to. A main lug only mlo panel only has main lugs and is intended to be fed by a main breaker upstream. You can feed it with less than 100 amps sent from my rct6203w46 using tapatalk. 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.

Main lug load centers are sometimes referred to as add on. If the panel was designed to be a main panel there would be a lug that connects the neutral ground bus to the panel. If you attach to lugs in the main box then you need to have a main breaker in the sub panel. Buy a 100 amp main breaker contractors pack at a big box cheapest way to go.

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. 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. Since you say a section is buried i assume garage is detached.

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