CN202663048U - Ground protection box of electric-shock-proof cable - Google Patents

Abstract

A ground protection box of an electric-shock-proof cable comprises a sealing box, an insulation board, a copper grounding bar, three cable sheath protectors and four moving wire clamps. The insulation plate is fixed in the sealing box, and the four moving wire clamps are arranged on the insulation plate. The copper grounding bar is fixed in the sealing box through an insulation supporting column and is connected with a wire clamping base of one moving wire clamp through a grounding connection bar. The lower ends of the three cable sheath protectors are connected with the copper grounding bar, and the upper ends of the three cable sheath protectors are respectively connected with wire clamping bases of the other three moving wire clamps through three copper connection sheets. A grounding cable and three drainage cables which are connected with a metal sheath of a protected three-phase cable are respectively guided into the sealing box through four sealing bobbin winding devices and are respectively connected with the four moving wire clamps. The ground protection box is high in protection level and reliable in work, protects an electrical cable sheath and can ensure personal safety of working staff.

Description

Protection against electric shock cable grounding guard box

Technical field

The utility model relates to a kind of heavy in section single core high voltage power cable metallic shield grounding guard box, belongs to the power transmission and distribution technical field.

Background technology

The heavy in section high pressure single-core power cables of 35kV, 66kV, 110kV and above is provided with metal sheath (or metal screen layer), when lightning wave or internal overvoltage flow along cable core, on the cable metal sheath higher impact (induction) voltage can appear; When the system short-circuit fault electric current was flowed through cable core, very high line-frequency induction overvoltage also can appear on the cable metal sheath.Overvoltage may puncture protective coverings of cable insulation, causes cable metal sheath multipoint earth faults, has a strong impact on the normal operation of power cable even significantly shortens useful life of cable.Be induction overvoltage and the fault overvoltage on the restriction power cable metal sheath, and avoid forming circulation in sheath, usually with the direct ground connection of cable metal sheath one end, the other end is then by being installed in the cable protective layer protector ground connection in the cable grounding guard box.

The earth terminal of existing cable ground protection case adopts the insulator of epoxy casting resin, has separated up hill and dale theoretically the current potential of guard box casing and earth terminal, presents high impedance; And in actual motion, often because environmental factor such as weathering and ionization, causes occurring between guard box earth terminal and the casing ionization or ageing of insulation, present Low ESR, and cause to have potential difference between ground protection case and the ground, be easy to cause personal injury.And existing cable ground protection case adopts the outside screw mode of connection, and its ground protection line easily comes off, and equipment and personal safety in serious threat.In addition, traditional cable ground protection case sealing property is bad, and box house easily enters moisture, forms condensation or ponding, and degree of protection is not high.

The utility model content

The purpose of this utility model is to overcome the deficiencies in the prior art, the protection against electric shock cable grounding guard box that a kind of degree of protection is high, use safety is provided.

The alleged problem of the utility model realizes with following technical proposals:

A kind of protection against electric shock cable grounding guard box comprises stuffing box, insulation board, copper earthing bar, three cable protective layer protectors and four mobile wire clamps in the formation, described insulation board is fixed in the stuffing box, and four mobile wire clamps are installed on it; Described copper earthing bar is fixed in the stuffing box and by grounding connection row by the insulating supporting post and is connected with the tension seat of a mobile wire clamp; The lower termination copper earthing bar of three cable protective layer protectors, the upper end is connected with the tension seat of other three mobile wire clamps through three copper braces respectively; Earth cable and three leading cables that join with the metal sheath of protected threephase cable respectively four sealing wire passing devices on the sealing tank wall are introduced stuffing boxs and are connected with four mobile wire clamps respectively.

Above-mentioned protection against electric shock cable grounding guard box; described sealing wire passing device comprises wire-passing tube, back-up ring, O RunddichtringO, push pipe and nut; the inwall of described wire-passing tube is stepped; the end that its internal diameter is less is docked on the cable-through hole on the stuffing box sidewall; the end that internal diameter is larger is positioned at the stuffing box outside and is provided with the external screw thread that is complementary with nut; described back-up ring abuts on the halfpace on the wire-passing tube inwall; described O RunddichtringO leans against on the back-up ring; described push pipe one end inserts in the wire-passing tube and the top is pressed on the O RunddichtringO, and the other end and nut are affixed.

Above-mentioned protection against electric shock cable grounding guard box, described stuffing box comprises casing and seal cover, the upper limb of described casing is connected with seal cover by box-frame, is provided with sealing strip at the binding face of box-frame and seal cover.

The utility model utilizes mobile wire clamp to be connected with external cable, and is easy to operate, quick, cable connects reliable, fundamentally stopped contacting of stuffing box casing and each cable connecting terminal; External cable is introduced in the stuffing box through the sealing wire passing device, has guaranteed the sealing of cable grounding guard box, and external humidification is difficult for entering, and has improved the degree of protection of guard box.

The utility model degree of protection is high, reliable operation, when power cable sheath is protected, can guarantee staff's personal safety.

Description of drawings

Below in conjunction with accompanying drawing the utility model is further specified.

Fig. 1 is structural representation of the present utility model;

Fig. 2 is the A-A cutaway view.

Each label is among the figure: 1, seal cover; 2, sealing strip; 3, box-frame; 4, casing; 5, copper brace; 6, cable protective layer protector; 7, copper earthing bar; 8, support column; 9, tension seat; 10, mobile wire clamp; 11, insulation board; 12, support; 13, wire-passing tube; 14, O RunddichtringO; 15, nut; 16, back-up ring; 17, grounding connection row; 18, leading cable; 19, built-in earth cable hole; 20, push pipe.

Embodiment

Referring to Fig. 1, Fig. 2, the utility model is comprised of seal cover 1, sealing strip 2, box-frame 3, casing 4, copper brace 5, cable protective layer protector 6, copper earthing bar 7, support column 8, mobile wire clamp 10, insulation board 11, support 12, wire-passing tube 13, O RunddichtringO 14, nut 15, back-up ring 16, grounding connection row 17, push pipe 20.Although nut 15 and push pipe 20 are two parts, when assembling, they are welded into one, both are with advance and retreat.

When using the utility model that the metal sheath of high pressure single-core power cables is protected; the leading cable 18 and the earth cable that connect this device and protected cable metal sheath can adopt the 10kV cable; at first unload lower sealing cover 1; one end of 10kV cable is passed push pipe 20 successively; O RunddichtringO 14; back-up ring 16; in the mobile wire clamp 10 of wire-passing tube 13 rear insertions; allow mobile wire clamp 10 clamp the core of 10kV cable; then nut 15 is tightened; make O RunddichtringO 14 depress distortion on the top of push pipe 20; gap between 10kV cable and the wire-passing tube 13 is shut, prevent that external humidification from entering.Four 10kV cables all connect complete after, again seal cover 1 is installed on the casing 4 and gets final product.

The overvoltage that produces on the metal sheath of power cable is introduced the earth through leading cable 18, mobile wire clamp 10, copper brace 5, cable protective layer protector 6, copper earthing bar 7, grounding connection row 17, mobile wire clamp and earth cable.

Claims (3)

1. a protection against electric shock cable grounding guard box is characterized in that, it comprises stuffing box, insulation board (11), copper earthing bar (7), three cable protective layer protectors (6) and four mobile wire clamps (10); Described insulation board (11) is fixed in the stuffing box, and four mobile wire clamps (10) are installed on it; Described copper earthing bar (7) is fixed in the stuffing box and by grounding connection row (17) by insulating supporting post (8) and is connected with the tension seat (9) of a mobile wire clamp (10); The lower termination copper earthing bar (7) of three cable protective layer protectors (6), upper end are connected with the tension seat (9) of other three mobile wire clamps (10) through three copper braces (5) respectively; Earth cable and three leading cables (18) that join with the metal sheath of protected threephase cable respectively four sealing wire passing devices on the sealing tank wall are introduced stuffing boxs and are connected with four mobile wire clamps (10) respectively.

2. described protection against electric shock cable grounding guard box according to claim 1 is characterized in that, described sealing wire passing device comprises wire-passing tube (13), back-up ring (16), O RunddichtringO (14), push pipe (20) and nut (15); The inwall of described wire-passing tube (13) is stepped, the end that its internal diameter is less is docked on the cable-through hole on the stuffing box sidewall, the end that internal diameter is larger is positioned at the stuffing box outside and is provided with the external screw thread that is complementary with nut (15), described back-up ring (16) abuts on the halfpace on wire-passing tube (13) inwall, described O RunddichtringO (14) leans against on the back-up ring (16), described push pipe (20) one ends insert in the wire-passing tube (13) and the top is pressed on the O RunddichtringO (14), and the other end and nut (15) are affixed.

3. described protection against electric shock cable grounding guard box according to claim 1 and 2; it is characterized in that; described stuffing box comprises casing (4) and seal cover (1); the upper limb of described casing (4) is connected with seal cover (1) by box-frame (3), is provided with sealing strip (2) at the binding face of box-frame (3) and seal cover (1).

Images