Switchgear covers the breakers, switches and fuses of a power system along with the busbars, instrument transformers, relays and enclosures they are built into. Medium-voltage switchgear is often metal-clad, with withdrawable breakers in separate compartments, while high-voltage switchgear is either air-insulated in an outdoor yard or gas-insulated in a compact indoor hall. It is rated by voltage, normal current, short-time withstand current and internal arc classification.
The 11 kV switchgear has oil breakers, every racking operation on it is a risk until it's replaced.
Also heard as
- SWGR
- gear
Related terms
Disconnector
Off-load switch that provides a visible isolating gap but is not built to make or break load current.
SF6
Sulphur hexafluoride: a dense, highly insulating gas used to quench arcs in high-voltage switchgear.
Rack out
To wind a withdrawable breaker out of its connected position in metal-clad switchgear to isolate it.
Bus
Rigid conductor or common node in a substation or switchboard where several circuits connect and share power.