How to check the short circuit and leakage fault in the home with multimeter
There are many ways to use multimeters. Here, I list the common methods to check short circuit, open circuit and leakage of multimeters, hoping to help everyone. Shortcomings, welcome to add.
Check the short circuit with multimeter
Check whether there is a short circuit point in the line. First, cut off the circuit breaker, then turn off all switches and all devices in the line (all devices that can be unplugged should be unplugged).
The multimeter selects "buzzer" to measure at the lower opening of the circuit breaker-two probes contact the zero line and live line of the lower opening of the circuit breaker respectively. If the multimeter beeps, it proves that there is a short circuit in the line; On the contrary, there is no short circuit.
Check the open circuit with multimeter.
All switches are still cut off, and the multimeter selects "buzzer". Make sure to measure the direction of the line and find both ends of the wire.
When measuring, the two probes of the multimeter touch the two ends of the wire respectively. If it can beep, it proves that the wire is not open. If there is no beep, it proves that there is a breakpoint in the wire.
What should I do 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 the wires at both ends. One end of the wire is connected to the multimeter, and the other end is used as a probe to contact the line to be tested-this is to extend the length of the probe of the multimeter by using the wire, which is often used in practical operation.
Multimeter to check leakage
Don't cut off the circuit breaker this time, just turn off all the switches in the line and unplug all the plugs. Select "750V~ range" for multimeter, and measure at the circuit terminal (measure at the position of socket, switch, etc., not in the distribution box).
Measure the voltage between live wire-neutral wire and live wire-ground wire respectively. If the two measurements are the same, or the first measurement is less than the second measurement, it is proved that there is no leakage in the line.
If the first measurement value is greater than the second measurement value, it proves that there is leakage in the line-the greater the difference between them, the more serious the leakage is.
