A rigid metallic strip or bar that consolidates electrical power from incoming feeders and distributes it to outgoing circuits. Usually made of copper or aluminum, it handles massive currents without the flexibility or insulation overhead of large cables. Faults on a bus are severe because they instantly affect all connected circuits.
Heard on the job
We need to isolate the main electrical bus before we can safely rack out the damaged breaker.
Also heard as
- busbar
- bus
Related terms
Bus
Rigid conductor or common node in a substation or switchboard where several circuits connect and share power.
Dead bus
Busbar with no voltage on it, the condition that lets a breaker close without synchronising checks.
Switchgear
Assemblies of breakers, switches, fuses, busbars and enclosures that control and protect power circuits.