While several advances have recently been made in the materials and designs of medium voltage accessories, the techniques for jointing and terminating low voltage cables have largely remained unchanged. Traditionally these have relied upon casting the jointed cables placed inside a slim, compact two part plastic mould with a casting resin typically polyurethane. The purpose of providing a slim, compact mould was to minimise the use of the casting resin which constituted the main price component. The slim mould made the accommodation of the joint with proper clearance between the cores and mould difficult if not impossible especially because of the curvature of the cable ends unwound from drums. Mixing and pouring of the resin, leakage through mould flanges and poorly sealed cable entry ends makes the installation craft sensitive and cumbersome. The resins have limited shelf life and cannot be stocked for emergency use in unpredictable cable breakdowns. The polyurethane resins are not effective in the presence of moisture and are hazardous to health. Raychem RPG, a pioneer in heat shrinkable cable accessories and the largest manufacturer of cable accessories in India now offer an ideal cable jointing system in the form of ‘RLVJ’ kits. RLVJ joints have been developed keeping in mind the customers requirements of reliability, safety, cost and convenience. RLVJ kits rely on the insulating and sealing properties of a unique mastic coated polymer tape ‘Polystix’ that forms a tough tenacious water tight seal on the cable insulation and femule while providing a high level of factory engineered insulation. Polystix can be easily and effectively applied by any electrician/jointer.. The only effort is the removal of the backing from the mastic and application over the connectors. An elastomeric core separator and mastic enhance the insulation and sealing system of the joint. RLVJ joints have a realiable electrical continuity of the armour through a tinned copper braid and are fully shielded with a steel mesh which in combination with a tough, radiation cross linked heat shrinkable sleeve having a hot melt adhesive coating on its inner surface, provides mechanical protection, sealing and corrosion protection. The kits have unlimited shelf life and can be safely stocked for emergency use. Free installation training is provided to enable the simplest craftsman to reliably, easily and quickly install RLVJ joints. The performance of RLVJ kits on both PVC cables and XLPE cables has been successfully evaluated at CPRI, Bangalore in accordance with the UK Engg. Recommendations C-81. Several lending utilities like BSES, BEST, NDMC etc have successfully introduced RLVJ kits in their system.
Factory Engineered Insulation
Reliable Moisture Sealing
No Curing Time
Fast And Economical
The conductors are connected by crimping . The connection insulated and sealed with Polystix.
An elastomeric core separator enhances the insulation and mastic stri ps are used in interstices.
Reinstatement of inner sheath, electrical continuity of armour with copper braid and mechanical protection with steel mesh.
Steel mesh and copper braids clamped to armour.
Shrinking the wrap around heat shrink sleeve having an inner coating with a hot melt adhesive.