Method for checking leakage of distribution box with multimeter
Before using a multimeter to detect electrical leakage in a distribution cabinet or box, we need to first check what fault phenomena have occurred in the distribution box and what obvious features 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, 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, place one probe on one of the two output lines on the load side, and touch the other probe against the wall, preferably 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, and use the same method to detect them one by one until the fault point is found.
Operation precautions
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.
This method is a relatively safe way to locate the fault point in a state of no electricity. This method is also applicable to the search for power users and factory leakage, but during the search, not only should the power supply line be disconnected, but also the neutral line should be disconnected to avoid electric shock accidents.
