Fault Point Searching Method Of Control Cable

In the past few decades, with the rapid development of economy, the cable industry has been greatly developed. The productivity of China's cable manufacturing industry shocked the world. With the expansion of power industry, rail transit industry, data communication industry, automobile industry, mining industry and other industries in China, the demand for wires and cables will also increase rapidly, and the cable industry will have a lot of room for development in the future. However, in the process of cable manufacturing and use, cable damage, cable conductor damage, iron core cutting and other failures may occur. Then, what are the methods for finding the fault points of control cables? Let's have a look!

Due to the small size of the control cable, it may be stretched during the manufacturing of the cable and the extrusion of the sheath, which may lead to the on-off fault. Now, we will discuss three methods to search the fault point:

Method of energizing capacitance: some cable manufacturers usually use capacitance comparison method to find the approximate position of the broken line. Continuous energization is the way to make the broken line point of the cable correct, which is inefficient. Generally speaking, it takes about an hour and a half to find the breakpoint. It is almost impossible to find the broken core in the flame-retardant cables completed by the shielding, sheathing and sheathing processes. If the construction is not good, the flame-retardant cables will be abandoned. This method is almost useless now.

Combination of capacitance method and induction method: this method is used for breaking the core of cable core. It requires that there is no clad metal layer outside the cable core and no extruded clad layer. The capacitance is used to find out the approximate position of the cable break, and then the induced voltage method is used to accurately find the break point. The induced voltage method is to connect 650V AC voltage at one end of the broken core of the cable, and the other end is grounded with other cores, and use the inductive pen that emits optical signals to test. This method is very simple and fast, and it is also the most used method at present. When the sensing pen slides from the broken core during the test, the signal will change and the broken point of the cable can be found correctly.

Combination of constant current source and bridge method: it is also a common method to use the constant current source to bake and destroy the insulation of the broken core of the flame retardant cable, and then use the bridge fault locator to accurately locate the fault point.