Pyrocondensation joint of xlpe insulated cable manufacturing process

1 scope

This technology is applicable to general industrial and civil building electrical installation engineering 10 (6) kV xlpe insulated power cable for heat shrinkable joints produced.

2 construction preparation

2.1 devices and materials requirements:

2.1.1 main material: cable head attachments, and the main material supplied by manufacturers supporting. And a certificate and instructions. The models, specifications, voltage levels comply with the design requirements.

2.1.2 supplementary materials: soldering, welding oil, cloth, Emery cloth, wire connections with Silicon grease, cleaning agents, petrol, and so on.

2.2 the main tools:

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

2.3 operating conditions:

2.3.1 completion of cable laying, insulation resistance test.

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 the construction site are clean, spacious, full of light. Construction site should be equipped with 220V AC.

2.3.4 outdoor construction, should set up a temporary tent.

3 operational processes

Manufacturers operating process according to the manufacturers process. When no process description, can be made according to the following procedures:

3.1 process:

Equipment check point → → Strip cable sheath stripping copper shield and semi-conducting layer → fixed stress pipe →

Series take over → wrap half belt and rubber → fixed insulated pipe installation shielding network and Earth →

Retaining collar → transmission running the acceptance

3.2 device checks. Unpacking check whether the physical quantity on the line with the packing list. Look there is no anomaly.

3.3 Strip cable sheath (Figure 2-28):

3.3.1 straighten cable: the cable stay flat after due allowance, at the ends of two cables to be connected respectively within two metres of straight, clean, overlapping 200mm, in the Middle as Center marking, as the Joint Center.

3.3.2 stripping outside nursing layer and the armored loaded: from center marking began in two root cable Shang respectively volume take 800mm, and 500mm, stripping except nursing layer; from fracture 50mm of armored loaded Shang with wire lashing three circle or with armored loaded with card good, with hacksaw along copper wire lashing at or clip edge saw a ring marks, depth for steel with thickness 1/2, again with screwdriver will steel with pointed pry up, then with Kesi clamp clip tight will steel with stripping except.

3.3.3 dissection and internal sheath: armored fracture measured 20mm sheath, sheath stripping in the rest, and remove the filler.

3.3.4 saw wires: wire, sawing at the center point.

3.4 strip shielding and semi-conducting layer (Figure 2-29): from Center to both ends of wire 300mm stripping the shield and shield fracture measured 20mm semiconducting layer and the rest stripped. Thoroughly clean semiconductor on insulator surface quality.

3.5 fixed stress pipe (Figure 2-30): in the Center on both sides of the pipe is put into stress, makeshift copper shield 20mm, heat shrinking fixed. Set into the pipe (see Figure 2-30), the cable sheath being stripped long sleeved tight envelope, retaining sleeve protection layer is sealed by Strip short side into each phase wire put into inner and outer insulating tubes, semi conductive tubes, copper mesh.

Heat shrink heat shrinkable material is fixed, should be noted:

3.5.1 heat shrink temperature of 110 ℃. Therefore, adjust the torch flame is soft and yellow flame, beware of high-temperature blue flame, heat-shrinkable material to avoid burns.

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

3.5.3 flames spiraling forward to ensure full Uniform contraction in insulation around the pipe along the direction.

3.6 press successively took over: measured at wire tip connecting lengths of one-second and 5mm cut off core insulation, by core insulation fracture volume insulation 35mm, cut into 30mm-long Cone, press successively took over.

3.7 wrapped half belt and rubber: on the connecting pipe with sand cloth to get rid of the pipe edges and burrs and clean. Then half packs in the connecting pipe band and ends half a lap. At the ends of the cone wrapped rubber thickness not less than 3mm.

3.8 fixed insulating tubes:

3.8.1 fixed insulating tubes: pull the insulating tube from cable end respectively in the three sets of stress between the pipes at the ends, from the Center to the ends of heat contraction fixed. Heat flames towards the direction of contraction.

3.8.2 fixation of the insulating tube: Center the Outer Insulation tube insulation tube position. From the Center to the ends of heat contraction fixed.

3.8.3 fixed semiconducting tubes: two in turn on semi-conductive tubing insulation tube ends to erect steel shield 50mm, then heat shrink toward the Middle fixed at both ends.

3.9 installation shielding mesh and grounding wire (Figure 2-31). From the core line pull the shield at one end of the cable network, connecting copper shield at both ends, ends with copper wire lashing, used solder welding in prison. Ground rotate fastening wire ends with copper wire lashing at the armored prison welding, and welding on the shield on both sides in prison.

Joining the two metal sheath to buckle, and ends up with a wire, fur RASP to remove iron Thorn. Put on protective sleeve, sealed sleeve on both ends of the cable sheath on the head, a makeshift protective sleeve on each end and 100mm of the outer sheath of the cable, heat shrinking fixed.

3.11 transmission running the acceptance:

3.11.1 cable head end, as required by the test Department for testing.

3.11.2 acceptance: after passing the test, no-load power transmission runs 24h, no abnormal phenomenon, for the acceptance procedures, construction use. Also, submit change of negotiation, product certificates, test reports and run records and other technical information.

4 quality criteria

4.1 project:

4.1.1 cable joints closed tight, packed full, no bubbles, no crack, the wire tightly.

4.1.2 cable withstand voltage test, leakage current and insulation resistance must conform to the specification.

Inspection method: observation of examination and inspection and test records.

4.2 Basic project:

Cable head good looks, smooth, wrinkle-free, glossy, and can clearly see the outlines of its internal structure.

Inspection method: Visual check.

5 finished product protection

5.1 device upon opening the box, put materials in order in a porcelain dish, covered with white cloth, preventing debris from entering.

5.2 cable joints completed immediately fixed, power running. Delay to transmission or other assignments, give protection to cable head and wooden boxes to prevent smashing, touch.

6 quality problems to be noticed

6.1 starting from stripping to the completed must be continuous, once completed, to avoid damp.

6.2 cable production process, you should pay attention to quality issues (see table 2-9).

Common quality problems and prevention measures of table 2-9

Quality control measures of serial numbers often occur

1 large leakage current test clean wire insulated surfaces

2 heat shrink insulation tube local burns or matte, adjust the heating flame is yellow, heat flame not staying in one location

Circle in a certain direction, keep heat shrink, cutting the insulation tube

End to the 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.