Question 516Electricity & Electronics - Assistant Engineer

The correct answer is D: The circuit must be tested and proved dead first with a live-line tester, then grounded. This is the correct answer because before working on a high voltage system, it is critical to first verify that the circuit is de-energized and safe to work on. Testing the circuit with a live-line tester, which is designed to detect the presence of voltage, is the best way to confirm the circuit is truly dead. Only after verifying the circuit is de-energized should it then be grounded to ensure there is no risk of accidental re-energization. The other options are incorrect because they either do not require testing the circuit first (A and B) or recommend using an off-line tester instead of a live-line tester (C), which may not reliably detect the presence of voltage.