- lephone Cable with cellular polyethylene insulation, jelly filled with petroleum jelly and a polyethylene coating.
- For use in the Local Distribution network.
- Insulated conductors uniformly twisted together to form a pair.
- The water resistant filling compound is applied to the air spaces within the cable core to provide the water-proofness.
- Wrapping is applied over the cable core.
- A flat aluminium foil coated with copolymer on both sides is applied longitudinally over the core covering as screen.
- Black linear-low density polyethylene compound is extruded over the screen.
Physical Description
Conductors | Solid annealed bare copper conductors conforming to CCITT Yellow |
Insulation | Foam–skin polyethylene |
Cable Assembly | Twisted pairs ,cabled in a circular form |
Color Code | As indicated below |
Filling | Water resistant lling compound, applied to the gaps between the pairs |
Tape wrap | Non hygroscopic polyester tape, wrapped with 25% overlap |
Identification | Manufacturer name and year of manufacture |
Flooding | Water resistant flooding compound , applied between the core wrap and |
Screen ( Shield) | Two side Copolymer coated aluminum foil laid longitudinally, bonded |
Inner Sheath | Black Low Density PE |
Armouring | Galvanized steel wire armouring |
Outer Sheath | Black Low Density PE |
Surface Marking | Telephone symbol, length marking, telephone symbol |
Mechanical Parameters of basic conductors
Nominal Conductor Diameter (mm) | 0.5 |
Maximum Conductor Diameter (mm) | 0.51 |
Minimum Conductor Elongation, % | 15 |
Insulated Conductor diameter (mm) | 0.9 |
Insulation ultimate tensile force minimum (N) | 2 |
Electrical Properties
DC resistance @20˚C Ohm/km Maximum Average | 91 |
DC resistance @20˚C Ohm/km Maximum for 1% of cases | 96 |
Mutual Capacitance nF/km, max Average | 53 |
Mutual Capacitance nF/km, max for 1% of cases | 60 |
Pair to pair capacitance unbalance, pF max | 275 |
Insulation Resistance, 500V DC Minimum Mohm.km | 1500 |
Colour codes of unit
Pair No | Colour of conductor insulation | |
| A – wire | B – wire |
1 | White | Blue |
2 | White | Orange |
3 | White | Green |
4 | White | Brown |
5 | White | Grey |
6 | Red | Blue |
7 | Red | Orange |
8 | Red | Green |
9 | Red | Brown |
10 | Red | Grey |
Colour codes of tape lappings, Unit
1 | Blue |
2 | Orange |
3 | Green |
4 | Brown |
5 | Grey |
6 | White |
7 | Red |
8 | Black |
9 | Yellow |
10 | Violet |