Operations and Maintenance

DC and AC voltage, resistance, continuity, and (with limits) current; used for Voc, polarity, and continuity checks.

A DC-capable (Hall effect) clamp is placed around a single conductor to read current without breaking the circuit.

Currents in opposite directions (positive and negative) cancel; clamping both reads near zero.

A resistance check (often with a beep) confirming a complete, low-resistance path, done only on de-energized circuits.

Applies a high DC test voltage (e.g., 500–1,000 V) to measure insulation resistance between conductors and ground, in megohms.

Damaged or wet insulation, pinched conductors, water in connectors or boxes—a potential ground fault.