Introduction of Switchgear
A switchgear is a metal-clad assembly of breakers and switches used as a primary power distribution center. The breakers and switches are used to direct power to downstream electrical equipment. One of their primary functions is to prevent an electrical fault in one circuit branch from disrupting power to, or damaging equipment in, another branch. They do this by interrupting the faults before they can interfere with the other circuits.
Since there are very high power levels associated with switchgear, they are built strongly out of materials like steel so that they don’t blow apart under the electromagnetic forces generated during high-current faults.
The breakers and switches can be opened to isolate a circuit from its power supply. This allows important maintenance and other work to be done safely without risk of shock to the service technicians.
The switchgear connects to the incoming power line at the service entrance and distributes that power downstream to smaller loads. Those smaller loads can be load centers, motor control centers, transformers, motors, or any kind of lower-power panelboard.
It helps to think of the power distribution as a hierarchy. The high-wattage power first enters a building (like an industrial factory). That power enters the switchgear. The switchgear breaks the high-wattage power into smaller chunks and distributes them to lower-wattage distribution centers throughout the factory.
To say it another way, the power grid supplies an incoming line to a switchgear. The switchgear feeds a load center. The load center feeds low-power motors (low-power relative to any motors that might be fed by a switchgear directly). The load center can also feed low-voltage breaker panels used for things like lighting and power receptacles.
A switchgear is a critical piece of electrical equipment. It is a basic element in the power transmission and distribution process. It is used at the output of power plant generators, all the way down to the factory floor. A switchgear truly does serve and protect.