Power cable accessories
POLJ, SXSU, MXSU medium voltage, heat-shrinking joints 1-core and 3-core, screened, polymeric insulated cables 10(12) kV, 20(24) kV and 35(42) kV
Raychem revolutionized medium voltage joints when developed POLJ family. Common feature of POLJ joints is that they contain mechanical connector with shear head bolt. These EXRM-1260 connectors provide big cross section range taking, they are capable to connect alu and copper, solid or stranded conductors, without using pressing tool. The short JSCR electrical stress control tubings in them do not require big parking space at installation. Above the connector there is a 3-layer „Rayfit” tubings. Rayfit is the patent of Raychem, it consists 3 layer: the outer black layer is conductive for shielding. The middle red layer presses the inner insulation layer, which is important for excellent electrical stress control. Further advantages of these „sandwich” tubing are the one-step shrinking which reduces installation time, and this tripple layer tubing follows the moving of cable in case of short circuit or at the installation. The metal shielding of the cable is recovered by tinned copper mesh, that is fixed by roll springs at both connected cables, that provides a reliable current connection in case of short circuit.
POLJ family is available for 1-core and 3-core cables with copper wire or tape screen, with our without armour. Application range voltage: 10(12), 20(24), 35(42) kV, cross section: 25…630 mm2.
POLJ-12/3x…1x and POLJ-24/3x…1x are transition joints between an 1-core and a 3-core cable. The construction of these transition joints similar to an in-line 3-core cable joint, the sealing at 1-core cable side is solved by unique forceps with melting glue.
REPJ family is the repair joints version of POLJ. The design and components of the repair joint and the inline joint are similar. The longer length of the repair joint allows cut the damaged part out of the cable and replace it by a piece of cable core and two connectors. This allows repairing the cable for a length of up to 520 mm (10 kV and 20 kV) or 420 mm (35 kV).
SXSU is the traditional heat-shrinking joint family of Raychem. They do not include mechanical connector, but they are applicable either with mechanical connector or pressing sleeve. Application range voltage 10(12), 20(24), 35(42) kV cross section: 35…1200(!) mm2, for 1-core and 3-core cables, with copper wire or tape screen, with our without armour.
MXSU is the W-Europe version of POLJ family. The construction of MXSU is based on SXSU, but they include BSM type mechanical connector. BSM mechanical connectors with shear head bolt have got different application range than EXRM-1260 in POLJ, so with only one connector and with one MXSU joint the 95…240 mm2 cross section range can be covered in one step. The copper wire shield of both cables are connected to each other with small a mechanical connector (not a roll spring).
Application of MXSU family is voltage: 10(12), 20(24), 35(42) kV, cross section range 25…1000 mm2, for 1-core or 3-core cables with copper wire screen. In case of tape screened, or armoured cables or transition joint connection the POLJ family is recommended to use, because the standard MXSU joints without modification are not applicable on these cables.
CSJA pre-expanded, cold-shrink elastomeric inline joints for screened, 1-core polymeric insulated cables 10(12) kV, 20(24) kV and 35(42) kV
Raychem CSJA products are an „all-in-one” joints, it means that key components (joint body, the copper shielding braid and outer tubing) are pre-expanded on one spiral holdout, which results in a very short parking length during cable preparation and offers a fast and easy-to-install system. The conductors are connected by a BSM mechanical connector that is supplied with the joint. The one-piece body of CSJA joints is made of silicone rubber, and its elastomeric feature results big cross section range taking.
Electrical stress control over the screen cut area is provided by conductive cones integrated in the silicone joint body with an exactly defined geometrical design. The electrical stress control of the connector area is made with an integrated conductive shield performing as a Faraday cage. Conductive screening over the insulation is the part of the joint body as well.
The silicone rubber joint body shrinks onto the insulation upon removal of the spiral holdout. Outer side of silicon body there is a copper braid, this solderless earth connection connects the metallic shield of the connected cables. The flipped backs of the pre-installed outer tubing are rolled out on the cablejacket wrapped up with the mastic. The outer tubing builds up a reliable moisture seal and corrosion protection.
For installation no need any special tool. The kits include the lubricating grease. They can be installed where using flame is forbidden. The spiral holdout can be easily removed from the joint body with low release force.
CSJA family is available on voltage level 10(12), 20(24), 35(42) kV, cross section 35…630 mm2, orderable with our without mechanical connector with shear head bolt.
Transition joints for polymeric insulated cables to 3-core belted, oil-paper insulated cables with one common metal sheath (SB structure) 10(12) kV TRAJ-12, MXSU-12
Common feature of Raychem transition joints is that, the oil-paper cores are completely covered with transparent oil barrier tubing (OBTF or SPOE) that stops penetration the oil to the polymeric side, ruining the plastic components and keeps the oil insulation in the paper cores. The breakout area on the paper side is sealed by an adhesive lined, conductive breakout and conductive tubing (CNTM) which are installed over the cores and the end of the metal sheath. Thus the paper cable is transformed to a quasi polymeric cable construction and the cables jointed similarly.
TRAJ-12 (TRAnsition Joint) and MXSU-12 transition joints contain mechanical connector with shear head bolt and with separation wall. This connectors have sector shape hole in it which fits the cable core structure of an SB cable. Heat-shrinkable triple-extruded elastomeric tubing provides the correct thickness of insulation and the screening over the insulation and the connector. The metal sheath, armour and the metal screen of the polymeric cable are jointed with solderless connections (EPPA roll spring). A metal tape is wrapped around the joint area to provide a metal screen and additional protection. The outer sealing and protection are performed by an adhesive coated, thick-wall heat-shrinkable tubing and a breakout.
The difference between TRAJ-12 and MXSU-12 is the type of the sleeve. While in TRAJ-12 there is EXRM-0961 mechanical connector with cross section range 70-120 mm2 and 150-240 mm2 in MXSU-12 there is BSMB connector with cross section range 70-150 mm2 and 95-240 mm2. Electrical stress control in MXSU is similar what is in the traditional Raychem EPKJ-17 transition family (EPKJ-17 do not include connector) so the length of MXSU joints are longer than TRAJ.
Transition joints for screened polymeric insulated cables to screened, paper insulated cables with one metal sheath per phase (HL structure) 20(24) kV and 35(42) kV TRAJ-24, MXSU-24, TRAJ-42
The oil-blocking in TRAJ-24 and MXSU-24 transition joints and the transformation of cable structure to a quasi polymeric cable structure is as same as in the 10 kV transition joints. The The oil-blocking in TRAJ-24 and MXSU-24 transition joints and the transformation of cable structure to a quasi polymeric cable structure is as same as in the 10 kV transition joints. The differences are in the connection of metal armour and core shielding to the polymeric cable, that comes from the different cable structure of HL cable.
On these voltage levels the most spreaded cable structure is the 3HL (3x screened cores with one metal sheats per phase with one common armour), but there are transition joints fro 1HL or for 3SB cable structure as well.
The difference between TRAJ-24 and MXSU-24 is the type of the sleeve. While in TRAJ-24 there is EXRM-1260 mechanical connector with cross section range 70-150 mm2 and 120-240 mm2 in MXSU-24 there is BSMB connector with cross section range 50-150 mm2 and 95-240 mm2. Electrical stress control in MXSU is similar what is in the traditional Raychem EPKJ-24 transition family (EPKJ-24 and RPKJ-24 do not include connector) so the length of MXSU joints are longer than TRAJ.
On voltage level 35(42) kV the transition joint with shear head bolted connectors is TRAJ-42 family. The cross section 70-120 mm2 and 120-240 mm2. Transition joints without connectors are the traditional Raychem EPKJ-36 family.