How to use high and low voltage clamp-on ammeters to quickly locate leaking points
New fast find leakage fault point method for the four-line single fire clamp meter method. Find the steps are: first disconnect the total circuit breaker in the station area, the station area of low-voltage four-wire line (including zero line) in parallel, and then connected to a phase of the power supply and then use the HV and LV clamp-on ammeter phase-by-phase step-by-step measurement to determine the leakage fault point. Four lines of single-fire clamp meter method of workload is small, the fault point to find fast, ** risk is small.
1. The first end of the measurement judgement. First of all, the distribution room (box) leakage circuit blackout. Test clear no voltage, the circuit A, B, C three-phase fuse zero removed and zero line (N) unlocked (such as no fuse can be out of the circuit, including the zero line unlocked, mark the zero line and the phase sequence of other phase lines). Connect the four wires in parallel, take any phase of the fire wire after power supply, so that all four wires are single-fire energised. At this time, you can use high and low voltage clamp ammeter were measured on the four wires. If the measured Gann line shows a large current value, while the other three lines of value is very small or zero, the current value of the occurrence of a serious leakage fault. Such as checking the four lines of measurement are not small readings, indicating that all phases have different degrees of leakage. Regardless of the situation, according to the current value of the first big after the principle of small and gradually find the leakage fault point.
2. The first pole again to confirm. In the distribution room (box) the first end of the leakage fault phase has been confirmed, and then use the insulated rod clamp ammeter in the base out of the pole, reconfirm the value of a large serious leakage fault phase, and keep in mind the fault phase. And then along the fault phase, to the receiving side of the gradual measurement to find.
3. T-branch search. When encountering the T-branch line measurement to find, T-branch pole as a reference, the first measurement of the main line A1 point (the direction of the powered side), and then measure the branch line A2 point. If the measured A1 main line measurement point leakage value is large, while the A2 point has no leakage display. It means that the leakage fault point is still in the back section of the main line, but not in the T word branch line.
4. Cross-branching search. When encountering the cross branch line measurement to find, the cross branch pole as a benchmark, the first measurement of the main line A1 point (the direction of the powered side). If there is no leakage display, it means that the fault is at point A2 (branch line "ten" side) or point A3 (branch line "one" side). If A2, A3 point at the same time there is a leakage current, it means that there are multiple ground faults, according to the current value of the first big and then small principle of gradual search for leakage fault points. And so on, step by step, will soon be able to find a serious leakage fault points or users. This method is also very fast and accurate in the search for a line of a ground theft.
