The Method of Detecting Leakage Current of Indoor Hidden Lines using Clamp Ammeter
The shape meter can detect the AC current flowing on a single wire, the condition is whether the sensitivity of the meter meets the requirements of the current size, the sensitivity of the general clamp meter is not high, if the leakage current is too small, the clamp meter cannot reflect it;
When measuring, because the measured wire must pass through the ring formed by the jaws, it must be measured at the place where the hidden wires are exposed (such as at the junction box) where the jaws can clamp the wire, but usually the leakage can be caused by the jaws. When the meter measures the magnitude of the leakage current, the leakage current has already triggered the leakage switch, the current in this circuit has been cut off, and there is no current on the line.
When there is no power on the circuit, use a megger to measure the insulation resistance of the wire to the ground to determine whether there may be leakage.
Can the clamp ammeter be used to measure the current to see if the wire is leaking? Or electricity theft?
1. The clamp ammeter is a special tool for measuring AC current. Measuring current with a clamp ammeter cannot accurately distinguish electricity stealing behavior, because there are many and complicated means of stealing electricity.
2. Just take the case of "bypassing" the meter (such as changing the transformer ※※) to steal electricity as an example. There is no abnormality in the three-phase current, but the measurement data is low, which cannot be measured by using a clamp ammeter. A comprehensive approach will work.
3. The same is true for single-phase power supply lines, such as smart prepaid meters. Criminals can slow down the meter by changing the meter (the original standard *※), but it cannot be measured by clamp meters alone.
4. It is also very difficult to measure the leakage with a clamp meter, because the leakage current is very small (if the current is large, it is not a leakage, but a short circuit), and the measurement data has no reference.
The method of judging the user's internal circuit and equipment leakage by using a clamp ammeter
The method of using the clamp ammeter to judge the user's internal circuit and equipment leakage:
Use a clamp ammeter to measure the leakage current at the user's power inlet line, and at the same time put the user's electrical equipment and lamps into and out one by one, and check the leakage current changes by watching the clamp ammeter to find the leakage equipment and lamps .
If all the equipment and lamps are good, or the equipment with leakage has been withdrawn, but the clamp ammeter shows that the user still has leakage current, it may be that the low-voltage line of the user has leakage, and it should be dealt with according to the specific situation . For the leakage fault of the pre-buried and concealed pipeline, only the treatment method of changing the line or rewiring can be adopted.
