As a kind of insulating material, insulating tube plays an important role in various industries such as electrical. So what are its main functions?
The insulating tube is the same as other insulating products, and it also has excellent flexibility and elasticity attributed to it, as well as outstanding dielectric and chemical resistance, so it is suitable for wiring insulation of motors, electrical appliances, exteriors, radios and other equipment And mechanical maintenance.
Nowadays, the conductor structure of commonly used insulated pipes has two types: cable type and guide rod type. In the cable type, the lead cable of the transformer is directly passed through the bushing, which is convenient for installation. When the operating current is greater than 600A, the cable-through structure device is more difficult, and the guide rod structure is generally used.
Insulating pipes often use oil or gas as the insulating medium, and are generally made into transformer bushings or circuit breaker bushings, and are often used for voltage levels below 35 kV. The inner cavity between the conductor of the insulating tube and the porcelain sleeve is filled with transformer oil to act as a radial insulation. When the voltage exceeds 35 kV, the conductor is covered with an insulating tube or cable to strengthen the insulation. Mainly used for ultra-high voltage transformers and circuit breakers.
The use of insulating tubes can also greatly reduce the corrosion damage of equipment wires and other accessories, and at the same time, it also plays a role in extending the operating life of the equipment. Capacitive insulating sleeve is one of them. When the condenser core is made of adhesive tape, it has high mechanical strength, can be installed at any angle, has good moisture resistance, and is simple in structure and repair. There is no need to install the sleeve, and the core can be lowered. Turning into a short tail type, reducing its size.
This kind of insulating tube is different from others. It uses oil paper as the condenser core. Generally, it has a lower porcelain sleeve. The lower part is larger in size, more sensitive to moisture, and has high sealing requirements. The advantage is that the insulation materials and processes are easy to solve, and the dielectric loss is small. Partial discharge function is good.
At high voltage levels, the requirements for top-notch products and processes are relatively high, and it is difficult to eliminate the air gap, resulting in low partial discharge voltage. Due to problems such as high dielectric loss and low partial discharge voltage, taped paper capacitive bushings have been gradually replaced by oiled paper and capacitive insulating bushings.
Later, a glue-impregnated paper insulating sleeve was developed on this basis. The condenser core is made of insulating paper rolls, and then vacuum impregnated with synthetic resin, and then heat-cured. Its functions are both adhesive paper and oil paper. The advantages of capacitive bushings.