Detecting Electricity Theft and Leakage with Clamp Ammeters
Clamp on ammeter is a practical electrical tool for measuring low-voltage lines, characterized by high accuracy and good stability. Power workers can use it to detect low voltage currents, microcurrents, and check equipment leakage, testing whether the main circuit is stealing electricity. This article introduces the use of clamp ammeters for detecting electricity theft and leakage
Check for leakage inside the circuit and equipment
Measure the leakage current with a clamp ammeter on the main circuit, and then turn off the electrical equipment in sequence. For each shutdown, use a clamp ammeter to detect the change in leakage current on the circuit and locate the leaking equipment. If all electrical equipment has been turned off, but the clamp current meter still shows leakage current, it should be due to leakage in the low-voltage line, and the line should be replaced or the leakage point should be detected again
Determine which phase line is leaking electricity
At the distribution transformer, disconnect the neutral wire on the outgoing side of the low-voltage line contactor, remove the fuse and install it on one of the phase wires. Use a clamp ammeter to measure the current of that phase, 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 the leakage current
When the low-voltage line is powered on, the single-phase wire and neutral wire should be placed in the clamp of the clamp ammeter at the same time during detection, and the three-phase three phase wires and neutral wire should also be placed in the clamp at the same time. If there is no leakage fault, the phasor sum of the load current flux is zero, and the clamp ammeter reading is also zero; If there is leakage current, the clamp ammeter can detect the leakage current.
