Clamp ammeter inspection for theft and leakage
The clamp type ammeter is a practical electrician tool for measuring low-voltage lines, with high accuracy and good stability, which are its main characteristics. Electric power workers can be used to detect low voltage currents, micro currents, and check equipment leakage, testing whether the main circuit is stealing electricity. This article introduces the detection of electricity theft and leakage using a clamp ammeter
Check for leakage inside the circuit and equipment
Measure the leakage current on the main line using a clamp type ammeter, and then turn off the electrical equipment in sequence. For each shutdown, use a clamp type ammeter to detect changes in the leakage current of the line to find the leaking equipment. If all electrical equipment has been turned off, but the clamp ammeter still shows leakage current, it should be a low voltage line with leakage, and the line should be replaced or the leakage point should be detected
Determine which phase line has leakage
At the distribution transformer, disconnect the neutral wire on the outlet side of the low-voltage line contactor, remove the fuse and install it on one of the phase lines. Measure the phase with a clamp ammeter, and the measured current is the leakage current of that phase. Test the leakage current of other phase lines in sequence
Determine the location of leakage
When the low-voltage line is powered on, both the single-phase and neutral wires should be placed in the clamp of the clamp ammeter during detection, and the three phase and neutral wires of the three-phase should also be placed in the clamp at the same time. If there is no leakage fault, then the phase sum of the load current magnetic flux is zero, and the indication of the clamp ammeter is also zero; If there is leakage current, the clamp ammeter can detect it.
Precautions:
When searching for leakage faults, pay attention to * * and maintain a distance between the human body and live parts.
Clamp the live and zero wires together to measure the leakage current of electrical equipment. (Note 2 pieces)
Clamp the ground wire to measure the leakage current of the electrical equipment's grounding wire. (Attention should be paid to individual pieces)
Clamp the three-phase and four wires together to test the total leakage current. (Note 4 pieces)
Clamp the main line and measure the current of the main line. (Attention should be paid to individual pieces)
