How to Correctly Use a Multimeter (MM) to Easily Identify the Causes of Electric Leakage
There have been more reports of faults caused by electrical leakage, and I believe many electricians have put a lot of effort into finding the cause of electrical leakage. So how can we easily identify the cause of electrical leakage by using a multimeter correctly?
Fault diagnosis and analysis:
Before analyzing where the leakage is, we need to first look at what fault phenomena have occurred in the home and what obvious characteristics are present; Next, observe the surface for any obvious fault points, and then proceed to the next step of inspection.
1. First, disconnect the main isolation switch of our power supply incoming line and turn off all electrical loads of the user, such as unplugging the refrigerator plug, disconnecting the water pump switch, etc.
2. Place the gear of the digital multimeter in the 200M range of the ohm range, with one probe placed on one of the two output lines on the load side and the other probe touching the wall. It is recommended to touch the grounding wire or temporary grounding wire. After the number displayed on the multimeter stabilizes, the insulation resistance value of the main circuit is read out. If the insulation resistance value is less than 0.5 megohms, then there is a problem with the main circuit. If the insulation resistance is above 0.5 megohms, then it can be ruled out that there is a problem with the main circuit. Measure another wire using the same method 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 various electrical appliances using the same method until the fault point is found.
Precautions for operation:
1. When using the multimeter in the 200M ohm range, be careful not to touch the metal part of the probe with your hand during measurement, as this will result in inaccurate readings.
2. When measuring various electrical equipment, pay attention to discharging first to prevent capacitive currents in the equipment from injuring people.
