Clamp ammeter to check electric leakage
Clamp ammeter is the most practical electrical tool for measuring low-voltage lines. Its main features are high precision and good stability. Electric workers can use it to detect low-voltage current, micro-current, check equipment leakage, and test whether the main line is stealing electricity. This article introduces the clamp ammeter to check electric leakage detection
Check whether there is leakage inside the line and equipment
Use a clamp ammeter to measure the leakage current on the main line, and then turn off the electrical equipment in turn, and use a clamp ammeter to detect the change of the line leakage current every time one is closed to find the leakage equipment. If all electrical equipment is turned off, but the clamp ammeter shows that there is still leakage current, it should be that there is leakage in the low-voltage line, and the line should be replaced or the leakage point should be detected
Judging which phase and phase wire is leaking
At the distribution transformer, disconnect the neutral wire on the outlet side of the low-voltage line contactor, take out the fuse and install it on one of the phase lines, and measure the phase with a clamp ammeter, and the measured current is the leakage current of the phase. Test the leakage current of other phase wires in sequence
Determine the location of the leakage
When the low-voltage line is energized, the single-phase line and the neutral line should be placed in the jaws of the clamp ammeter at the same time, and the three-phase three-phase lines and the neutral line should also be placed in the jaws at the same time. If there is no leakage fault, the phasor sum of the load current magnetic flux is zero at this time, and the indication of the clamp ammeter is also zero; if there is a leakage current, the clamp ammeter can detect the leakage current.
Precautions:
Pay attention to safety when looking for leakage faults, and keep a safe distance between the human body and live parts.
Clamp the live wire and the neutral wire together to measure the leakage current of the electrical equipment. (Note 2)
Clamp the ground wire to measure the leakage current of the ground wire of the electrical equipment. (note the single root)
Clamp the three-phase four-wire together to test the total leakage current. (Note 4)
Clamp the main line and measure the current of the main line. (note the single root)
