Standards
• CW 1128 (Unscreened jelly filled cables)
• CW 1128/1179 (Screened jelly filled cables)
• CW 1128/1252 (Self supporting jelly filled cables)
• CW 1128/1198 (Steel wire armoured jelly filled cables)
• CW 1128/1179/1198 (Steel wire armoured screened jelly filled cables)
Construction
Conductors
Solid annealed bare copper 0.4/0.5/0.6/0.63/0.9 mm as per class 1 of BS 6360/IEC 60228
Insulation
Cellular polyethylene as per BS 6234/BS EN 50290-2-23/IEC 60708
Twisted Pairs
Insulated conductors are twisted into pairs with varying lay length to minimize crosstalk
Cabling Element
Twisted Pairs
Cable Core Assembly
Cables are composed of 10-pair units. Any extra pairs form a separate unit. Units are identified by colour coded binders. Standard construction is per CW 1128 given in Cable Make Up Chart below
Core Wrapping
One or more non-hygroscopic polyester tapes are helically or longitudinally laid with an overlap. These tapes furnish thermal, mechanical as well as high dielectric protection between shielding and individual conductors
Inner Bedding (for armoured cables)
Black polyethylene compound
Armour (for armoured cables)
Galvanized steel wire armour is applied over an inner polyethylene sheath
Filling
The cable core interstices are filled with petroleum jelly to avoid longitudinal water penetration within the cable.
The water resistant filling compound is applied to the air space between non-hygroscopic tape and shield, shield and sheath within the cable core
Sheath
Black low density polyethylene as per BS 6234/IEC 60708/ASTM D 1248 which is compounded to withstand exposure to sunlight, temperature variations, ground chemicals and other environmental contaminants
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Outdoor Telephone Cables