Loadcenters are enclosed in a sheet metal box which can be ordered for surface, flush
or semi-flush mounting in a wall. The cover has knockouts where breakers are mounted. Most loadcenters come with a door to
cover the breaker handles. Both indoor- and outdoor-rated loadcenters are available. Units can have as few as two single-pole
spaces or as many as 42 single-pole spaces. Two- and three-pole plug-in breakers can also be inserted. Individual breakers
can be sized up to 100 amps.
Panelboards are electrical distribution panels that use bolt-on circuit breakers. They're usually used in
heavy commercial and industrial buildings where higher amperages are needed.
Panelboards are enclosed in a heavy gauge sheet metal box which can be ordered for
surface or flush mounting on a wall. Panelboards have interiors like similar loadcenters except that the circuit breakers
must be bolted to the interior bus system. An interior cover is placed over the circuit breakers and extends to the panel
cover. The panel cover is made of heavy gauge sheet metal and usually has a door which covers the circuit-breaker handles.
Two- and three-pole bolt-on breakers can be installed. The breakers can be sized up to 100 amps for lighting panels, and higher
for power panels.
Panelboards are rated for total load, such as 100A, 225A, 400A, etc. The circuit breakers installed cannot exceed the
panel rating. Single-width panelboards are limited to 42 circuits. If additional circuits are required, a double-width panelboard
can be used.
Panelboards are usually custom-assembled at the factory to meet specific job requirements. Loadcenters are usually stock
items. Your supplier probably offers a good selection of loadcenter housings and large quantities of the more common plug-in
breakers that are inseru will insert into the housing.