How to use a multimeter to check for short circuits, open circuits, and leakage?
There are many ways to apply a multimeter. Below, I will list common methods for checking short circuits, open circuits, and leakage with a multimeter, hoping to be helpful to everyone. Any shortcomings are welcome to be supplemented.
Check for short circuit with a multimeter
To check if there are any short circuit points in the circuit, first cut off the circuit breaker, and then turn off all switches and equipment in the circuit (all devices that can be unplugged are unplugged).
Select the "beep gear" on the multimeter and measure at the lower port of the circuit breaker - two probes, touching the zero and live wires of the lower port of the circuit breaker respectively. If the multimeter emits a beep, it indicates a short circuit in the circuit; On the contrary, there is no short circuit.
Check for open circuit with a multimeter
Still, cut off all switches and select the "beep gear" on the multimeter. Determine the direction of the line to be measured and locate both ends of the wire.
When measuring, the two probes of the multimeter are in contact with both ends of the wire. If a beep can be emitted, it indicates that the wire is not open; If there is no beep, it indicates a breakpoint in the wire.
What if the distance between the two ends of the wire is too far? Find a wire that is confirmed to be intact and peel off both ends of the wire. One end of the wire is connected to a multimeter, and the other end is used as a probe to contact the line to be tested - this method uses the wire to extend the length of the multimeter probe, which is often used in practical operations.
Check for leakage with a multimeter
Don't cut off the circuit breaker this time, just turn off all switches in the circuit and unplug all plugs. Select "750V~gear" for the multimeter and measure at the circuit terminal (at sockets, switches, etc., not in the distribution box).
Measure the voltage between the live wire zero wire and the live wire ground wire separately. If the two measured values are the same, or if the first value is less than the second value, it indicates that there is no leakage in the circuit.
If the first measurement value is greater than the second, it indicates that there is leakage in the circuit - the larger the difference between the two, the more severe the leakage.
