How to Measure Circuit Continuity with a Digital Multimeter
Methods for Distinguishing Live and Neutral Wires with a Digital Multimeter
① Rotate the multimeter selector switch to the AC 250 V or 500 V range. Connect one test probe to the power‑supply conductor, and connect the other probe to ground (such as a water pipe or damp location).
② If the multimeter reading is close to 220 V, the measured point is the live wire.
③ If the reading remains unchanged, turn down the selector switch range step‑by‑step to the lowest range. If there is still no obvious reading, the measured point is the neutral wire.
④ If no ground point is available, adopt the following method: rotate the multimeter selector switch to the highest AC‑voltage range. Connect one test probe to the measured point of the power supply, and pinch the other test probe between your index finger and thumb. If the multimeter shows a reading, the measured point is the live wire; if no reading appears, it is the neutral wire or protective‑earth wire.
Methods for Testing Whether a Circuit Is Energized with a Digital Multimeter
Procedures for testing whether a circuit is energized or short‑circuited using a digital multimeter are as follows:
1. Checking Circuit Continuity
Switch to the resistance range or diode‑buzzer range, and measure between the two conductors of the circuit. A reading close to 0 Ω or buzzer sound indicates good circuit continuity. A reading of 1 or no buzzer sound indicates an open‑circuit fault.
2. Checking for Circuit Short‑circuit
Switch to the resistance range or diode‑buzzer range, and measure between the two conductors of the circuit. A reading close to 0 Ω or buzzer sound indicates a short‑circuit between the two conductors. A reading of 1 or no buzzer sound means the two conductors are normal with no short‑circuit fault.
