Zhujiang Cable teaches you how to solve common faults in cable lines

During the use of the cable, we will encounter many failures. Zhujiang Cable will teach you how to solve the common failures of the cable line.

 The most common faults in cable lines include mechanical damage, insulation damage, insulation dampness, insulation deterioration, overvoltage, and cable overheating faults. When the above-mentioned fault occurs in the line, the power supply of the faulty cable should be cut off, the fault point should be found, the fault should be checked and analyzed, and then repair and test should be carried out. The power supply can be restored after the removal of the fault. Below, Fenjiang wires and cables will list some common failure points for you~

The most direct cause of cable failure is that the insulation is reduced and breakdown. The main reasons are:

a. Overload operation. Long-term overload operation will cause the temperature of the cable to rise and the insulation aging, so that the insulation will be broken down and the construction quality will be reduced.

b. Electrical aspects include: the construction process of the cable head does not meet the requirements, the sealing of the cable head is poor, the moisture invades the inside of the cable, and the insulation performance of the cable is reduced; when the cable is laid, protective measures are not taken, the protective layer is damaged, and the insulation is reduced.

c. In terms of civil construction, there are: poor drainage of pipe trenches in industrial wells, long-term soaking of cables in water, which damages the insulation strength; too small industrial wells, insufficient cable bending radius, and long-term damage by external squeezing force. Mainly mechanical brutal construction in municipal construction. Cut and cut the cable.

d. Corrosion. The protective layer has been subjected to chemical corrosion or cable corrosion for a long time, causing the protective layer to fail and the insulation to decrease.

e. The quality of the cable itself or the cable head accessories is poor, the cable head is poorly sealed, the insulating glue is dissolved, and cracked, which causes the resonance phenomenon in the station to be the line disconnection fault, which makes the line phase capacitance and the ground capacitance and the distribution transformer excitation inductance form resonance Loop, which excites the ferromagnetic resonance.

Harm of resonance caused by disconnection fault

Disconnection resonance In severe cases, the superimposition of high frequency and fundamental frequency resonance can make the overvoltage amplitude reach 2.5 times the phase voltage [P], which may cause the neutral point of the system to shift, and the winding and wire may have overvoltage. Insulation flashover, lightning arrester explosion, electrical equipment damage. In some cases, the phase sequence of the load transformer may be reversed, and overvoltage may be transmitted to the low-voltage side of the transformer, causing harm.

Guangdong Zhujiang Wire and Cable Co., Ltd. is a large-scale wire and cable enterprise integrating R&D, manufacturing and sales. The imported wire and cable manufacturing technology, advanced wire and cable production equipment, and testing equipment escort the "Fenjiang" cable. The company strictly controls the purchase of raw materials, production equipment, and production processes. Therefore, the appearance of the produced wire and cable products is smooth and round, and the color is uniform. Each product has been repeatedly tested in 12 procedures and undergoes high-voltage testing before leaving the factory to ensure that every millimeter of wires meets the factory standards. The precise and scientific production process ensures that the insulation layer is even thick and safe to use.