Cable breakpoint determination method

When a breakpoint occurs inside the cable or cable, it is difficult to visually determine the determined position of the breakpoint due to the wrapping of the outer insulation.

Here are a few ways to quickly determine the breakpoints of wires and cables:

Non-damaged cable method

1. digital multimeter method
First, connect one end of the cable with the breakpoint to the 220V live wire and the other end to make it float. Move the multimeter's gear position to make it to the AC 2V voltage block. Then, starting from the Firewire access terminal of the faulty cable, hold the black test lead with one hand and the red test lead slides slowly along the insulation of the faulty cable. The voltage at the no break point of the cable is about 0.445V. When the red test pen moves to a certain place, the voltage value displayed by the multimeter drops to 1/10 of the normal voltage, that is, 0.04V. At this point, it can be basically concluded that the breakpoint is at the position forward (fire line access end) 15cm.
This method cannot be used if the shield of the shielded wire is not damaged.

2. induction pen method
First, remove the cable around the breakpoint cable and connect the cable with the breakpoint to the live wire. Then use the induction pen to move slowly perpendicular to the cable. When the AC signal of the induction pen disappears, you can judge the breakpoint at the test. At the point, the error is no more than 10cm.

3. Polyline method
For short cable test breakpoints, you can use the method of bending, and connect the two ends of the cable to the ends of the red and black test leads of the multimeter. Bend back and forth from one end of the cable. If the multimeter is on and off at this time, the breakpoint is here. According to this method, the breakpoint is always checked.
 

Method of damaging the cable
4. acupuncture discrimination
This method uses the continuity of the cable to check the breakpoint of the cable. Insert the segment of the breakpoint cable into the steel pin, and then use a multimeter to measure the on-off condition. The difference is where the breakpoint is. However, this method destroys the insulating layer and is easily caused by other problems in the later use of the cable.

5. professional instrument detection method
In addition, for the judgment of the underground cable fault point, the fault point can be judged by the audio detector.

For the cable length and the judgment of the short circuit and the breaking point, a cable fault telemeter can be used.

Different methods are used to judge the breakpoint according to the actual situation. The above several methods can basically determine the cable breakpoint.