How do I know if my wiring harness is bad?

The actual project maintenance and repair, for maintenance personnel are most afraid of nothing more than encountering a break in the wire and cable can not find the breakpoint in what place. Although the actual maintenance of our weak power project, encountered cable problems will directly find ways to change the line or re-laying, but today we discuss what methods can be measured technically cable breakpoints!

When the cable internal media breakage fault, in the case of its external package with insulation skin is not visible in the exact location, including strong power weak power are so, usually looking for breakpoints is the idea of segmentation.

For example, a cable in the middle of a place can not be, respectively, from the two ends and the middle of the three points of measurement, which side is not accessible and then take the center point of the measurement, so that the range is narrowed down by inspection to quickly find the location of the breakpoints.

So usually, what are the measurement methods to accurately measure the break point of the wire and cable?

1, multimeter detection method:

First of all, the whole cable is not connected to the strong end of the cable on the firewire, the other end of the empty. The multimeter dialed to AC2V file, from the cable connected to the beginning of the end, while pinching the tip of the black pen, while the red pen along the insulating skin of the wire slowly moving, the display shows the voltage value of about 0.445V or so.

When the red pen moved to a certain place, the display of the voltage suddenly dropped to 0.0 volts, about one-tenth of the original voltage, from the position forward (firewire access) of about 15cm is where the breakpoint.
2, inductive pen test method

Induction test pen, that is, with an electronic screen, you can detect the voltage and through the equipment. First exclude the breakpoint cable around the cable has a power supply, and then there will be a breakpoint in the cable connected to the firewire, the pen perpendicular to the wire, hold down the "inductive breakpoint test" button in the wire forward and move slowly, such as the test pen to detect the sudden disappearance of AC signals, you can judge the breakpoint in the test point, the error is up to no more than 10cm.

It should be noted that: the breakpoint wire around the cable can not be with power. Another reminder is that this method is not foolproof, short cable effect is obvious, the longer the cable the worse the effect.

3, the use of audio detector

Audio detector is a use of single-frequency or multi-frequency signals, can test the continuity of the line to identify line faults in the instrument. Can be connected to any switch, router, PC terminal in the case of direct line finding. When tracing the cable line, no need to peel off the outer skin of the line, simple, fast, and can identify the location of the line break point.
4、Cable fault tester

It is a comprehensive set of cable fault detection instruments. It can test the high resistance flashover fault of cable, high and low resistance grounding, short circuit and cable breakage, poor contact and other faults, if equipped with acoustic legal point instrument, it can accurately determine the precise location of the fault point. Especially suitable for testing various types of power cables and communication cables of different voltage levels.
5, folding line detection method

Connect one end of the wire with a break point to the black pen of the multimeter, and the other end to the red pen. Multimeter playing in the resistance 200Ω file. In the most likely place to break the line (such as frequent bending points) back and forth bending. If the multimeter shows that the fluctuation of the time, this is the break point. Still can not judge, it is necessary to start bending from one end of the cable, until you find the breaking point. This method is suitable for shorter cables.

6, needle detection method

This method belongs to the damage detection method, in the broken cable segments inserted into the steel needle, with a multimeter to measure the steel needle to the end of the cable through the cable to determine the breakpoint of the cable.

It is not recommended under normal circumstances, because it will damage the insulation layer, and it is easy to cause other problems in the later use of the cable, especially in the environment of high humidity. This method is the use of cable pass-through to identify where the breakpoint of the cable.

7, pulling the wire detection method

This also belongs to the damage detection method, generally not used in practice, but also a method listed together, using a vise to pull the cable end of the broken line, such as the breakpoint near the end of the cable, it is easy to pull the insulation skin. This method is used for the broken point in the vicinity of the cable end of the cable.

To measure the break point of the wire and cable, you can refer to the several methods introduced today, we are in the conditions, or with the help of instruments and equipment to improve efficiency is better.