What component must come off last when de-energizing a grounded circuit?

When de-energizing a grounded circuit, it is crucial to ensure that the system is safely and completely isolated from any electrical potential before maintenance or repairs are conducted. The earth clamp serves as a safety device, providing a path to ground for any potential fault current.

By removing the earth clamp last, you ensure that the circuit remains grounded until all other potentially live components, such as the main switch, fuses, and circuit breakers, have been disconnected. This sequence minimizes the risk of electric shock or accidental re-energization during the maintenance process because it preserves a direct connection to ground, allowing any residual voltage to dissipate safely.

The other components listed, while important in the de-energizing process, should be removed prior to the earth clamp to ensure that the grounding remains intact until immediately before work begins. This order of operations is a critical safety practice in electrical work.