Heat shrinkable terminations made of cross-linked polyethylene insulated cable technology

1 scope

This technology is applicable to general industrial and civil building electrical installation engineering 10 (6) kV xlpe insulated cables for indoor, outdoor heat shrinkable Terminal head.

2 construction preparation

2.1 devices and materials requirements:

2.1.1 the equipment and materials used must conform to the voltage level and design requirements, and have quality certificates.

2.1.2 main material: insulating trigeminal gloves, insulating pipes, pipe stress, braided copper wire, rubber pipe, gas pipe, sealing tape, seal, waterproof skirt. Auxiliary material: terminals, soldering, cleaning agents, Emery cloth, white, petrol, soldering paste.

2.2 the main tools:

Blowtorch, crimping pliers, steel measuring tape, hacksaw, electric iron, electric cutters, nippers, screwdriver, large dishes.

2.3 operating conditions:

2.3.1 operation of larger venues, the construction site clean, and equipped with 220V AC.

2.3.2 operating environment temperature 0 ℃, relative humidity below 70% is strictly prohibited in the rain, fog, wind, weather and construction.

2.3.3 Spider-man (on the pole) should set the platform, above the construction site set up tents to prevent dust intrusion (outdoor).

2.3.4 transformers, high-voltage switch cabinet (high pressure switch), the cables are installed, qualified cable insulation.

3 operational processes

Manufacturers operating process according to the manufacturers process. When no process description, can be made according to the following procedure. From start to peel cut into the completed must be continuous, once completed, to avoid damp.

3.1 process:

Insulation test

Equipment check point welding Strip cable sheath → line →

→ Wrap fill, fixed three-prong gloves stripped copper shield layer and conductive layer → fixed stress pipe crimping Terminal →

Fixed gas pipe transmission seal running the acceptance

Fixing insulation tube

Fixed rain dress → fixed sealing pipe fixed gas pipe transmission running the acceptance

3.2 equipment check point: unpacking check that the material conforms on the packing slip number, the appearance of any abnormal phenomenon, according to the order of operations around the large dishes.

3.3 insulation shake test of cables: cable head open at both ends, 2500V shake table, pass the test before they can transfer to the next procedure.

3.4 strip cable sheath (Figure 2-23):

3.4.1 stripping outer sheath: clamp vertical cables fixed. From the cable ends measure 750mm (indoor measuring 550mm), peel off outer sheath.

3.4.2 strip armored: from fracture of outer sheath measuring 30mm armour, after using the wire tie, others stripped.

3.4.3 cushion within the Peel: from inside the armored fracture measured 20mm cushion, others stripped. Then, remove filler, separate wires.

3.5 welding ground (Figure 2-24):

Braided copper wire cable steel belt and shielded lead grounding wire. The braid apart into three new weave around each phase separately, soldering iron, solder welding in shielding copper tape. Polish steel weld zone with Emery cloth, He Gangkai after lashing wire welding in prison. In an airtight Tin filled with woven wire, formation of moisture.

3.6 bags around the rubber, fixed three-prong gloves (Figure 2-25):

3.6.1 wrap around rubber: fill the plastic fill and wrap with cables three core branches. Makes its appearance into olive-shaped. When you wrap sealing tape, first clean the surface of the cable sheath and cable wires. Maximum diameter of sealing tape around the package should be greater than about 15mm of the cable diameter, ground Pack in it.

3.6.2 fixing of trigeminal gloves: mittens into the trigeminal root. Then, using a blowtorch, heat shrinking fixed. When heated, from the roots of the glove in order to contract fixed at both ends.

3.6.3 heat-shrinkable material heat shrinkage should be noted:

3.6.3.1 heat shrink temperature of 110~120℃.

3.6.3.2 adjust the torch flame is soft and yellow flame, beware of high-temperature blue flame, heat-shrinkable material to avoid burns.

3.6.3.3 starting heating the material, flame to slowly approach material, material moving around, even heating, and keep the flame towards the (deep) directions preheat the material.

3.6.3.4 the flame should be spiral, guarantee the full Uniform contraction around along the direction of the pipe.

3.7 stripping copper shield layer and conductive layer: gloves that end 55mm g copper shield, the other stripped. Get 20mm from the copper shield Terminal semiconducting layer and the rest stripped.

3.8 production stress cone. After using alcohol to wipe clean the cable core operates according to the requirements of Figure 2-26.

3.9 fixed-stress pipes: detergents clean copper shield, semi-conductive layers, insulating surfaces, ensure no carbon footprint. Then, three-phase respectively into the stress pipe, lapped copper shield 20mm, heat shrinking fixed up from lower end of pipe stress.

3.10 crimp terminal: make sure the lead length, at Terminal hole depth plus 5mm, stripping the core insulation, both cut into "the pencil". Crimp terminals, clean surface with the rubber filling terminals with insulation between the gap and the terminals on the pit, and overlap insulation and terminals 10MM exhibition, making it smoother.

3.11 fixed insulated pipe: clean the insulating tube, stress control and finger surface, nest insulation pipes to the trigeminal root (tube top out of rubber 10MM). Starting from root heating fixed.

3.12 fixed-seal pipe: gas sealed tube nozzle in Terminal, Preheat terminals from top heat fixed. Complete the first cable production within households.

3.13 fixed rainproof skirt (Figure 2-27):

3.13.1 fixed three-hole rain dress: three-hole rain dress size into. Then, heated neck fixed.

3.13.2 fixed single-hole rain-proof dress. By drawing into single-hole rain skirts, heated neck fixed.

3.14 fixed seal: sealed tube in Terminal nozzle, Preheat terminals from top heat fixed.

3.15 fixed gas pipeline: gas pipe separately in a sealed tube, heat fixed. Outdoor head finished.

3.16 transmission running the acceptance:

3.16.1 test. After completion of the first cable production, as required by the test Department for testing.

3.16.2 acceptance. After passing the test, no-load running 24h no abnormal power transmission, for the acceptance procedures unit. Submit change negotiations, product brochures, certificates, test reports and operation records and other technical documents.

4 quality criteria

4.1 project:

4.1.1 cable head closed tight, packed full, no bubbles, no cracks; wires tightly. Withstand voltage test results, the leakage current and insulation resistance code requirements must be met.

4.1.2 cable head of semiconductors, shield wrap beyond stress cone maximum, pyramidal symmetry, the surface is smooth.

4.1.3 cable installation, immobilization phase sequence is correct.

Inspection method: Visual check and inspect the installation, test records.

4.2 Basic project:

Cable head good looks, smooth, wrinkle-free and shiny.

Inspection method: Visual check.

5 finished product protection

5.1 after the equipment and materials inventory, put in order in a porcelain dish, covered with white cloth, preventing debris from entering.

5.2 the first cable production is completed, notify the test Department test as soon as possible. After passing the test, fixed. Then connected to the transformers, high-voltage switch, power running. Delay to transmission or have other jobs, protection of cable head, preventing hit, hit the cable head.

6 quality problems to be noticed

6.1 starting from stripping to the completed, must be carried out continuously, at once, so as not to damp.

6.2 the first cable production process, quality problems to be noticed (table 2-8).

First cable production process quality problems should be paid attention to in table 2-8

Serial number control measures for common quality problems

1 excessive leakage current test and they clean the wire insulation surface

Trigeminal glove, heat shrink insulation tube partial Burns matte or adjust the heating flame is yellow. Heat flame not staying in one place

3 heat-shrinkable tube heat contraction around the bubbles in a certain direction, keep heat shrink

4 when the heat shrink insulation tube end, cracked when cutting the insulation tube, face flat

Quality of 7 records

7.1 product certificate.

7.2 equipment inspection records.

7.3 cable test report form.

7.4 mutual inspection records.

7.5 change record of negotiation.