The protector consists of two parts: zinc oxide valve plate group and discharge counter. The silicone rubber type zinc oxide valve plate group is directly surrounded by high-strength epoxy glass cloth cylinder, valve plate group, upper and lower electrodes and wiring screws to form a whole. The valve column is made of perceptual EPDM or silicone rubber as the shell material, and it is molded at one time. Seal moisture and explosion problems.

With sufficient mechanical strength, the valve column is directly hot-pressed with the shell material, and there is no gap around the valve column, which also solves the problem of protecting the single-core high-voltage cable to generate an alternating magnetic field through alternating current, and induce induction on the cable metal sheath. Electric potential, the magnitude of which is related to the length of the cable. Avoid circulating current through the metal sheath of the cable. The metal sheath of the single-core cable can only be grounded at one end, and the other end is grounded through the protector. During normal operation, the voltage of the ungrounded end to ground is only tens to hundreds of volts; when the system is symmetrical Or asymmetric short-circuit, the short-circuit current can reach tens of kiloamperes, and the induced overvoltage on the metal sheath can be as high as ten thousand volts; under the action of lightning shock waves, the induced overvoltage can be as high as hundreds or even thousands of volts, which endangers the protective layer. Insulation, therefore, it is necessary to install BWKL medium voltage cable protector on the ungrounded end.