What are the characteristics of cable connector?

(1) The 35kV SF6 fully sealed switchgear cable terminal is to insert the entire terminal into a special socket located in the fully sealed small room of the switchgear, and the exposed parts are all grounded.

(2) 10kV SF6 fully sealed switch cabinet (ring network cabinet) cable terminals are divided into plug-in right-angled (elbow-shaped) separable connectors (for 200A) and plug-in right-angled bolt-type separable connectors (mainly used for 630A) ). There is also a special protective cap for the cable terminal, that is, a special protective cap is used to cover the live part.

The cable terminal is prefabricated in the factory with the main components, and passed the test in the factory.The cable terminal is fully inserted into the special socket located in the fully sealed compartment of the switch cabinet, and the exposed part is grounded.

2. Connection between cable terminal and switch cabinet

(1) The 35kV plug-in terminal is connected by moving and static plugs, and the cable terminal is inserted into the prefabricated cable socket of the switch cabinet. The socket is completely isolated from the inside of the switch cabinet, and the installation of cables does not affect the state of the inside of the switch cabinet. Figure 4-12 is a schematic diagram of 35kV plug-in cable termination.

(2) Plug-in right-angle separable connectors are generally suitable for transformer feeders. The electrical grounding line contact with the switch cabinet is composed of sliding parts. Directly insert into the support of the switch cabinet through the contact, and connect with the electrical part of the switch cabinet. The support is completely isolated from the inside of the switch cabinet, and the installation of cables does not affect the internal state of the switch cabinet.

(3) The plug-in right-angle bolt-type separable connector is connected by M16 stud bolts to the screw holes on the support of the switch cabinet. The support is completely isolated from the inside of the switch cabinet, and the installation of cables does not affect the internal state of the switch cabinet.

1) The switch cabinet accessory is to apply voltage to the special accessory, and carry out the withstand voltage test on the cable terminal through the connection device inside the switch cabinet.

2) The cable terminal accessories carry out the withstand voltage test on the plug-in cable terminal. It does not need to separate the cable terminal and the switch cabinet, and can be carried out directly on the switch cabinet. Therefore, the connection part of the line isolating switch of the switch cabinet and the cable is required to have the same withstand voltage capability as the cable.

(2) Cable line electrical inspection and grounding measures:

Fully sealed switchgear has perfect safety protection measures. The safety measures of the switchgear have been very complete, with the function of preventing misoperation, which can prevent cable construction when the grounding knife is not closed. However, it is still necessary to increase the on-site safety measures during the actual construction of the cable. According to the requirements of DL 409-1991 “Electrical Industry Safety Work Regulations”, when working on a wire stop, the circuit must be tested, discharged, and grounded. However, these tasks cannot be implemented on the cable lines connecting the fully sealed switchgear. The judgment of whether the cable line has electricity or no electricity can only rely on the judgment of the operating state of the switchgear, which requires a dedicated electrical inspection device.

With the close integration of switchgear and cable terminal work, electrical inspection and installation work grounding will be carried out through the switchgear.

1) Electrical inspection through the switch cabinet: The instrument panel of the fully-sealed switch cabinet is equipped with electrical inspection devices, which pass the secondary circuit electrical inspection.

2) Electrical inspection through a dedicated electrical inspection device: If a 35kV fully-sealed switchgear with plug-in terminals is used, the manufacturer can provide a dedicated electrical inspection device for direct electrical inspection of empty cable positions. However, after the plug-in terminal has been installed, it is not possible to directly perform an electrical test on the terminal part of the cable terminal. If a 10kV plug-in terminal is used, it can conduct electrical inspection on the electrical inspection site reserved for the cable terminal through the special equipment provided by it. However, the information of this type of electrical inspection device is not obvious, and the specific operation depends on the reliability of the special equipment itself.