Which component switches board isolation?

Which component switches board isolation?

• A. Disconnect switches
• B. Circuit breakers
• C. Relays
• D. Fuses

Answer: (A)

When you need to isolate a distribution board for safe maintenance, you use a device that provides a clear, mechanical open in the supply path so no voltage remains at the board. This is a disconnect switch, an isolator. It is designed to be opened manually and can be lockout-tagout’d to ensure a guaranteed, visible break in the circuit, preventing re-energization while work is done. Circuit breakers mainly protect against faults by interrupting current and are not primarily intended to provide a deliberate, visible isolation point for routine maintenance. Relays are control devices that switch signals or low-power circuits, not for isolating a high-power board. Fuses protect by blowing when overcurrent occurs, but they don’t offer a controllable, intentional switch to isolate the circuit.

When you need to isolate a distribution board for safe maintenance, you use a device that provides a clear, mechanical open in the supply path so no voltage remains at the board. This is a disconnect switch, an isolator. It is designed to be opened manually and can be lockout-tagout’d to ensure a guaranteed, visible break in the circuit, preventing re-energization while work is done.

Circuit breakers mainly protect against faults by interrupting current and are not primarily intended to provide a deliberate, visible isolation point for routine maintenance. Relays are control devices that switch signals or low-power circuits, not for isolating a high-power board. Fuses protect by blowing when overcurrent occurs, but they don’t offer a controllable, intentional switch to isolate the circuit.