It is used to connect two adjacent cables. In the electric car charging cable line, in addition to connecting the cable core conductor for electrical connectivity, the connector of the self-contained cable should keep the oil flow in the wire core unobstructed. But because the connecting head is in the field manual operation, its process condition is poor. Therefore, the online core connection adopts the pressing condition to deal with the problem of electric field concentration at the wire core connection. By increasing the insulation thickness, the working field strength of the joint can be reduced to ensure the smooth operation of the connector. It is usually wrapped above the cable insulation to increase the insulation, and the two ends of the insulation to form a conical surface stress cone. The insulation shield is wrapped around the outside of the additional wound insulation to connect the insulation shield of the power cable at both ends. There is a bright steel tube outside to isolate the insulation from the atmosphere, so that it can withstand the oil pressure of the cable.
The internal insulation structure and size of the insulated joint are the same as that of the ordinary joint. Insulated joint of 110 ~ 220kV charging cable is mainly used in long length power cable lines to make the metal sheath or metal shield layer and semi-conductive layer of the cable at both ends of the joint be disconnected electrically so as to cross connect and reduce the loss of the shield layer.
The stop-plug joint is the weak link of electric car charging cable accessory, and it is also the joint with complex structure. It is mainly used in the sly impregnated paper insulated cable line whose drop is greater than the specified value, to cut off the oil circuit, so as to avoid the cable insulation dry, low-end power cable insulation oil pressure greater than the specified value.
There are two kinds of copper charging cable joints: ordinary joint and half plug stop joint. Common connection joint, used for electric car charging cable manufacturing length connection, its internal insulation structure is generally interphase with the self-accommodating charging cable joint, its shell is a copper pipe with a diameter slightly larger than the power cable pipeline. Half-plug stop joint, used for longer charging cable lines of steel tube. It is a joint designed to reduce the loss of a large number of power cable sleeves in case of oil leakage. It is used to separate the oil supply section and make the oil in the two sections flow through the insulation layer or bypass pipe of the power cable. At the connection between the steel pipe of the joint and the steel pipe of the power cable, the power cable oil circuit is separated by a sealed structure.