Insulator: Learn the Purpose, Cost, and Lead Time to Procure
Insulators make sure the energized parts do not touch the ground. All substation equipment in contact with an energized line or bus employs an insulator.
Current Transformer: Learn the Purpose, Cost, and Lead Time to Procure
Relays need to know the current magnitude – either for metering or protection. A current transformer (CT) fulfills this role, stepping down thousands of amps to (typically) 5A which is then fed to a relay.
Voltage Transformer: Learn the Purpose, Cost, and Lead Time to Procure
Relays need to know the voltage magnitude – either for metering or protection. A voltage transformer fulfills this role – it steps down thousands of volts to 67V/115V in high voltage stations (at the medium voltage the VT’s step it down to 120V) which is then fed to a relay.
Circuit Switcher: Learn the Purpose, Cost, and Lead Time to Procure
A circuit switcher is a switching device like a circuit breaker. It interrupts the power flow.
It is typically installed on the high voltage side of the transformer.
Disconnect Switch: Learn the Purpose, Cost, and Lead Time to Procure
Disconnect switches establish isolation points to enable equipment maintenance. They are installed on both sides of the circuit breaker, high-side of the transformer, and on the line exit. Switches cannot and should not be used to interrupt load current or fault current. A switch operation takes place after the circuit is de-energized.
