How to use a multimeter to detect lighting line leakage faults
Once the lighting line leakage phenomenon, not only waste of electricity, but also may cause electric shock accident. Leakage and short-circuit nature of the same, only the degree of accident development is different, serious leakage may cause short circuit. Therefore, the lighting line leakage, must not be taken lightly, should always check the insulation of the line, especially when the phenomenon of leakage is found, should promptly find out the reasons, to find out the failure point, and be eliminated.
Lighting line leakage is mainly due to: one is the wire or electrical equipment insulation by external damage; two is the line by long-term operation, resulting in insulation aging and deterioration; three is the line by the moisture invasion or pollution, resulting in poor insulation.
First of all, determine whether the leakage is indeed. Available pointer multimeter R × 10k file measurement of the size of the insulation resistance, or digital multimeter placed in the AC current file (at this time is equivalent to an ammeter), connected in series on the main switch, turn on all the switches, remove all loads (including light bulbs). If there is a current, then there is a leakage phenomenon. Determine the line leakage, you can continue to check according to the following steps.
1, to determine whether the phase line and the zero line leakage, or phase line and earth leakage, or both. The method is to cut off the zero line, if the ammeter indication is unchanged, it is the phase line and earth leakage; if the ammeter indication is zero, it is the phase line and zero line leakage; ammeter indication becomes smaller but not zero, it is the phase line and the zero line, the phase line and the earth leakage.
2, to determine the scope of leakage. Remove the split fuse or pull the circuit breaker, if the ammeter indication is unchanged, then the bus leakage; ammeter indication is zero, then the branch leakage; ammeter indication becomes smaller but not zero, it is shown to be the bus, the branch are leakage.
3, find out the leakage point. After the above checks, and then sequentially disconnect the line lamps and lanterns switch, when disconnecting a switch, the ammeter indicates a return to zero, the branch line leakage; if it becomes small, it indicates that this branch line leakage, there are other leakage; if all the lamps and lanterns switch disconnect, the ammeter indicates unchanged, it means that the section of the trunk line leakage. Sequentially narrow the scope of the accident, you can further check the section of the line joints, and wires through the wall and other places whether the leakage. After finding the leakage point, the leakage fault should be eliminated in a timely manner. Load end begins to detect the front end step by step, to see whether the work is caused by the line or components can be judged. After eliminating the short-circuit fault point, load and connect the qualified fuse and then send power.
Lighting line short-circuit, open-circuit, leakage is the most common faults, only we carry out specific measurements and analysis, in order to accurately identify the fault point, to determine the nature of the fault, and take effective measures to eliminate the fault as soon as possible.
