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In rainy and humid weather, many leakage faults can occur, and I believe electrical workers have thought hard about finding the cause of the leakage. In fact, you can easily find the cause of leakage using a multimeter. First, you need to have a normal multimeter.
Troubleshooting AnalysisBefore analyzing where the leakage occurs, we need to first observe what fault phenomena have appeared and what obvious features are present; secondly, we should visually check for any obvious fault points, and then proceed to the next step of inspection.
1. First, disconnect the main isolation switch of the incoming power supply, and turn off all electrical loads for the user, such as unplugging the refrigerator and turning off the water pump switch.2. Set the digital multimeter to the 200M ohm range. Place one probe on one of the two outgoing wires on the load side, and touch the wall with the other probe, preferably touching the ground wire or a temporary ground wire. After the number displayed on the multimeter stabilizes, read the insulation resistance value of the main circuit.If the insulation resistance value is less than 0.5 megaohms, then there is a problem with the main circuit; if the insulation resistance is above 0.5 megaohms, then the main circuit can be ruled out as the issue. Use the same method to measure the other wire and check the value to see if there is a problem with the main circuit.
3. Check the insulation resistance values of the branches and each electrical appliance, using the same method to test each one until the fault point is found.
Operating Precautions1. When using the 200M range of the multimeter, be careful not to touch the metal parts of the probes with your hands while measuring, as this will lead to inaccurate readings.2. When measuring each electrical device, make sure to discharge first to prevent electric shock from capacitive currents in the device. This method is relatively safe for finding fault points in a no-power state. This method is also applicable for finding leakage in power users and factories, but when searching, not only should the incoming power be disconnected, but the neutral line should also be disconnected to avoid electric shock accidents.
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