| Application | The cables are fully filled with petroleum jelly, being designed for use in access or trunk networks, from telephone exchange to subscriber area. The cables are suitable for installation in ducts and direct burial in the ground. |
| Standards | CW1236 |
| Construction | |
| Conductors: | Solid annealed bare copper 0.32/0.4/0.5/0.63/0.9mm 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 with up to 100 pairs are composed of 25-pair units or 12/13-pair units; cables with over 100 pairs are composed of 25, 50 or 100-pair units cabled together. Any extra pairs form a separate unit. Units are identified by colour coded binders. Standard construction is per CW 1236 given in Cable Make Up Diagram |
| 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 |
| Moisture Barrier: | An optional aluminium tape (0.15mm) coated with PE-copolymer on one or both sides is applied longitudinally with overlap over the cable core to provide 100% electrical shielding coverage and ensures a barrier against water vapor |
| 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, being able to withstand exposure to sunlight, temperature variations, ground chemicals and other environmental contaminants |
| Ripcord: | Ripcord may be provided for slitting the sheath longitudinally to facilitate its removal |
| Spare Pairs (optional): | Spare pairs may be incorporated for 200 and larger pair cables |
| Continuity Wire (optional): | One tinned copper drain wire may be longitudinally laid to ensure electrical continuity of the screen |
| Optional Construction | |
| Armoured Cable | Steel wire armour or corrugated steel tape armour is applied over an optional inner polyethylene sheath. For steel tape version, the 0.15mm thick steel tape is coated with a copolymer and applied with an overlap. An outer polyethylene sheath is applied over the armour |
Electrical Properties
|
Nominal Conductor Diameter |
mm |
0.32 |
0.4 |
0.5 |
0.63 |
0.9 |
|
Conductor Gauge Size |
AWG |
28 |
26 |
24 |
22 |
19 |
|
Conductor Size |
mm2 |
0.08 |
0.126 |
0.196 |
0.312 |
0.636 |
|
Maximum Average Conductor Resistance @20°C |
Ω/km |
223 |
143 |
91 |
58 |
28 |
|
Minimum Insulation Resistance @500V DC |
MΩ.km |
1500 |
1500 |
1500 |
1500 |
1500 |
|
verage Mutual Capacitance @800Hz* |
nF/km |
56 |
56 |
56 |
56 |
59 |
|
Maximum Individual Mutual Capacitance @800Hz (for 99% cases) |
nF/km |
64 |
64 |
64 |
64 |
65 |
|
Maximum Individual Capacitance Unbalance @800Hz pair-to-pair(for 99% cases) |
pF/500m |
275 |
275 |
275 |
275 |
275 |
|
Maximum Conductor Loop Resistance @20°C |
Ω/km |
470 |
300 |
192 |
114 |
60 |
|
Impedance @1KHz |
Ω |
1000 |
994 |
796 |
660 |
445 |
|
Impedance @100KHz |
Ω |
156 |
147 |
134 |
125 |
122 |
|
Impedance @512KHz |
Ω |
122 |
120 |
118 |
117 |
116 |
|
Impedance @1MHz |
Ω |
120 |
117 |
115 |
114 |
113 |
|
Maximum Average Attenuation @0.8KHz |
dB/km |
1.76 |
1.64 |
1.3 |
1.04 |
0.74 |
|
Maximum Average Attenuation @1KHz |
dB/km |
1.8 |
1.68 |
1.35 |
1.08 |
0.76 |
|
Maximum Average Attenuation @3KHz |
dB/km |
3.4 |
3.18 |
2.52 |
2.01 |
1.42 |
|
Maximum Average Attenuation @150KHz |
dB/km |
16.8 |
11.4 |
8.3 |
6.2 |
4.4 |
|
Maximum Average Attenuation @772KHz |
dB/km |
29.5 |
24.3 |
19.4 |
15.4 |
10.8 |
|
Maximum Average Attenuation @1000KHz |
dB/km |
33.5 |
27.1 |
21.4 |
17.5 |
12.8 |
|
Dielectric Strength Conductor to Conductor (3secs) |
V DC |
500 |
500 |
500 |
500 |
500 |
|
Nominal Insulation Thickness |
mm |
0.145 |
0.175 |
0.2 |
0.26 |
0.3 |
|
Nominal Insulated Conductor Diameter |
mm |
0.61 |
0.75 |
0.9 |
1.15 |
1.5 |
*Mutual capacitance values for 0.63mm & 0.9mm may be increased by 3% for cables with a nominal number of pairs less than 400.
Mechanical and Thermal Properties
Temperature range during operation (fixed state): -30°C – +70°C
Temperature range during installation (mobile state): -20°C – +50°C
Minimum bending radius: 10 x Overall Diameter (unarmoured cables);15 x Overall Diameter (armoured cables)
Colour Code
Standard colour code is per CW 1236 given in Colour Code Chart
