Main switchboard. The central electrical distribution point for a facility or installation, housing the main incoming circuit breakers, metering equipment, and primary distribution busbars. It acts as the first line of protection and control between the utility supply or main generators and the rest of the site's electrical network.
The utility is planning an outage, so we need to isolate the MSB and bring the backup generators online.
Also heard as
- main switchboard
Related terms
Switchgear
Assemblies of breakers, switches, fuses, busbars and enclosures that control and protect power circuits.
Bus
Rigid conductor or common node in a substation or switchboard where several circuits connect and share power.
Circuit breaker
A mechanical switching device capable of making, carrying and breaking currents under normal and fault conditions.