The ground indicating light on the main electrical switchboard is indicating a ground. What is the best procedure for locating the grounded circuit?

Correct Answer: Option D — open the circuit breakers on the distribution panel, one at a time, until the lights no longer indicate a ground

Systematic isolation is the standard troubleshooting method for ungrounded distribution systems. By sequentially opening circuit breakers at the distribution panel, the engineer identifies the specific branch circuit causing the ground fault when the indicating lights return to normal. This minimizes downtime and isolates the fault without de-energizing the entire switchboard.