The relevant technology of the power cable accessories installation requirement have?
power cable accessories is not the same as other industrial products, it is other factory can't supply good power cable accessories products, only supply accessories materials, parts or components, it is necessary through field device on the cable after constitute true, good cable accessories, assembled intact on the cable accessory combination collectively known as cable head, therefore, to adhere to the operation of cable accessories in good function, and the insulation of the cable itself has the same level not only requires the reasonable design, material features outstanding, processing quality strong attachments, also requires a field device process correct and careful operation, it is not only for personnel engaged in cable accessories equipment work of cable accessories related to common sense, and should have corresponding standards to strictly control the process.
general insulation level in general faults in the cable line is more affected by external factors in the joint area. Failure ( The external force damage) Most also occur on the cable connector accessories. No matter in theory or in practice can be confirmed joint position is the weak link of cable line, and cable joint quality is directly related to cable line operation safety, so the cable accessory equipment some skills necessary to meet the following requirements.
cable accessory equipment related skills:
1, commonly used in the electrical cable terminals, the regulations of the
cable terminal should be fit on electrical equipment, the electrical equipment equipment engineering construction and inspection standard 'of the relevant provisions.
( 1) Cable terminal phase color. Cable terminal phase color should be clearly marked, namely A yellow, green B, C, red and in phase with the system.
( 2) Safety net distance. Cable terminal end of the bare metal parts ( Including shield) Between different phase conductor and charged part of each phase, should agree with indoor and outdoor distribution equipment safety net from the specified value.
2。 35 kv and below the provisions of the commonly used earth wire cable accessories
when the cable insulation breakdown or system short circuit fault current in the cable conductor. Will guide people's congress (NPC), through the cable metal shielding layer for the personal and equipment safety, it is necessary to properly installed in cable terminal and tapping ground wire. In cable terminal and tapping. Should be based on 'grounding equipment construction and inspection standard' regulation, the cable terminal and connector of metal shell, cable shielding layer, kai, cable metal stents, choose ground wire or grounding line, joint metal shielding layer and kai outfit, need equipotential connection wire unicom.
the earth wire cable termination and the equipotential lines of joint, generally choose 25 mm braided tinned copper wire. The two ends of the joint metal shielding layer still need to add steel net connection.
in 6 - 10 kv cable line, cable when choosing zero sequence maintenance, when the cable ground zero sequence current transformer, the grounding wire should be directly grounded. When the cable ground above the zero sequence current transformer, the grounding wire should be insulated wire and through the zero sequence current transformer grounding.
3。 Ask 35 kv and below are commonly used in the cable joint of anti-corrosion and mechanical maintenance requirements
in the production of cable joint, due to the needs of the process, it is necessary to remove a cable outer sheath and kai layer, shall have the right to replace the original cable outer sheath material, as corrosion and mechanical maintenance structure.
( 1) Commonly used anti-corrosion materials are: one is kai belt; Another is heat shrinkable tube, both ends with two layers of tape is its waterproof package, then a layer of package from cats rubber belt.
( 2) The cable joint mechanical maintenance. Buried cable commonly used joint mechanical maintenance material is reinforced concrete maintenance box, box space filling fine cats soil or sand. New joint maintenance box with a hard plastic or epoxy glass steel production, the maintenance box because of the compact structure, light in weight and welcomed by users.