How to measure line leakage with a multimeter? How to check leakage with a multimeter

How to measure line leakage with a multimeter? How to check leakage with a multimeter

Strictly speaking, the measurement of line insulation resistance circuit whether the leakage should use a shaking table, shaking table is equivalent to a 1000v or 500v generator, the leakage current through the shaking table internal sampling resistor, on the resistor to produce a sampling voltage signal. Typically, a stable greater than 0.3 megohms is qualified.

Multimeter internal battery 9v to 15v, resistance gear can only determine the short circuit, rough judgement.

In fact, their own careful observation to suspect which broken line has a problem can be carefully open the line box, is a problem in the box, by pulling, knocking to observe the leakage insurance action. If the iron pipe and water, wire insulation in the pipe is not good, to determine the location, need to change the line.

1, power measurement: close disconnect all electrical appliances, with a multimeter RX10K file, a pen reception measurement of the firewire, another pen ground (or tap), should show the resistance of infinity, otherwise leakage.

2, charged measurement: with a multimeter 250 volts AC voltage file, measuring suspected leakage of the metal shell of the appliance, a pen connected to the shell, another pen ground (or tap), the pointer shows a voltage higher than 30-50 volts between, change the AC 50-volt gear, if the power supply to confirm that higher than 30 volts is a leakage, lower than 30 volts is normal, and then zero, the fire power supply plug line to the opposite measurement can be determined once again. If the power supply is confirmed to be higher than 30 volts, the leakage is below 30 volts.

3, fire and zero line (or fire and fire) between the leakage measurement: close and disconnect all electrical appliances, measuring the resistance between the fire and zero line should be infinite, otherwise it is a leakage. The above method of troubleshooting accuracy of 99.9%, convenient, rapid, practical, and megohm special shaking table just to do the project must be used, the maintenance of the use of inefficient, only the multimeter measurement to confirm that good, but the line is really a leakage, the use of shaking the table, but the multimeter does not measure leakage

Lighting line leakage causes a 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 moisture attack or pollution, resulting in poor insulation.

Leakage fault repair first judge whether the leakage is indeed. Available pointer multimeter R × 10k block measurement measuring road insulation resistance, or digital multimeter placed in the AC current block (at this time is equivalent to an ammeter), connected in series on the main switch, turn on all the switches, remove all loads (including bulbs). If there is a current, it means that there is a leakage phenomenon. Determine the line leakage, you can continue to check according to the following steps.

(1) 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 the earth leakage; if the ammeter indication is zero, it is between the phase line and the zero line leakage; ammeter indication becomes smaller but not zero, it is between the phase line and the zero line, phase line and the earth are leakage.

(2) determine the scope of leakage. Remove the tap 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, then 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 that the return to zero, the branch line leakage; if it becomes small, then this branch line leakage, there is a leakage elsewhere; if all the lamps and lanterns switch off, the ammeter indicates unchanged, then 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.