Application | The cables are designed for use as subscriber distribution cables and as connection between central offices. The cables are suitable for installation in ducts, direct burial in the ground and also for aerial installation with integral suspension strand. An armoured option is offered for direct burial installations. A figure-8 self support option is offered for aerial installation. |
Standards | Telcordia (Bellcore) GR-421 |
Construction | |
Conductors: | Solid annealed bare copper, 0.4/0.5/0.63/0.9mm, as per ASTM B-3/class 1 of IEC 60228 |
Insulation: | Solid medium or high density polyethylene as per ASTM D 1248/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 400 pairs are composed of 25-pair units or 12/13-pair units; cables with over 400 pairs are composed of 50 or 100-pair units. Any extra pairs form a separate unit. Units are identified by colour coded binders. Construction is per GR-421 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: | A layer of bare aluminium tape (0.2mm/8mil) is applied longitudinally with overlap over the cable core to provide 100% electrical shielding coverage and ensures a barrier against water vapor. In cables with more than 200 pairs, the aluminum tape may be corrugated for improved cable flexibility |
Sheath: | Black low density polyethylene as per ASTM D 1248/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 large 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: | 0.15mm thick corrugated steel tape armour is applied with an overlap over an optional inner polye-thylene sheath. An outer polyethylene sheath is applied over the armour |
Self-Support Cables | A 7-strand galvanized steel strand is used as support wire. Black polyethylene sheath covers both core and support wire in a figure-8 construction |
Aabbreviations | |
LAP (CAP): | Copolymer coated aluminium tape + PE sheath |
LAPSP (CAPSP): | LAP sheath + steel tape armour + PE sheath |
AP (ALPETH): | Bare aluminium tape + PE sheath |
PAP: | PE inner sheath + bare aluminium tape + PE sheath |
PASP: | PE inner sheath + bare aluminium tape + steel tape armour + PE outer sheath |
ASP (STAPETH): | Bare aluminium tape + steel tape armour + PE outer sheath |
CACSP: | Copolymer coated aluminum tape + copolymer coated steel tape armour + PE outer sheath |
LAPSP: | Copolymer coated aluminum tape +PE inner sheath + steel tape armour + PE outer sheath |
FIGURE 8 LAP: | Copolymer coated aluminum tape + PE outer sheath + self supporting |
Electrical Properties
Nominal Conductor Diameter | mm | 0.4 | 0.5 | 0.63 | 0.9 |
Conductor Gauge Size | AWG | 26 | 24 | 22 | 19 |
Maximum Average DC Resistance | Ω/km / Ω/mile | 140/225 | 87/140 | 55/88.6 | 27.0/43.4 |
Maximum Individual DC Resistance | Ω/km / Ω/mile | 144.2/232 | 89.5/144 | 56.5/91.0 | 28.0/45.0 |
Minimum Insulation Resistance @500V DC | MΩ.km / MΩ.mile | 1600/1000 | 1600/1000 | 1600/1000 | 1600/1000 |
Maximum Average Resistance Unbalance | % | 1.5 | 1.5 | 1.5 | 1.5 |
Maximum Individual Resistance Unbalance | % | 5 | 5 | 5 | 5 |
Average Mutual Capacitance | nF/km / nF/kft | 48.5-54.0 /14.8-16.5 | 48.5-54.0 /14.8-16.5 | 48.5-54.0 /14.8-16.5 | 48.5-54.0 /14.8-16.5 |
Maximum Individual Mutual Capacitance | nF/km / nF/kft | 57/17.4 | 57/17.4 | 57/17.4 | 57/17.4 |
Maximum Individual Capacitance Unbalance pair-to-pair | pF/km / pF/kft | 145/44 | 145/44 | 145/44 | 145/44 |
Capacitance Unbalance RMS pair-to-pair | pF/km / pF/kft | 45/13.7 | 45/13.7 | 45/13.7 | 45/13.7 |
Maximum Individual Capacitance Unbalance pair-to-ground | pF/km / pF/kft | 2625/800 | 2625/800 | 2625/800 | 2625/800 |
Maximum Average Capacitance Unbalance pair-to-ground | pF/km / pF/kft | 574/175 | 574/175 | 574/175 | 574/175 |
Maximum Conductor Loop Resistance @20°C | Ω/km / Ω/mile | 300/482 | 192/309 | 114/183.6 | 60/96.4 |
Impedance @1KHz | Ω | 994 | 796 | 660 | 445 |
Impedance @100KHz | Ω | 147 | 134 | 125 | 122 |
Impedance @512KHz | Ω | 120 | 118 | 117 | 116 |
Impedance @1MHz | Ω | 117 | 115 | 114 | 113 |
Maximum Average Attenuation @0.8KHz | dB/km / dB/kft | 1.64/0.5 | 1.30/0.39 | 1.04/0.32 | 0.74/0.22 |
Maximum Average Attenuation @1KHz | dB/km / dB/kft | 1.68/0.51 | 1.35/0.41 | 1.08/0.33 | 0.76/0.23 |
Maximum Average Attenuation @3KHz | dB/km / dB/kft | 3.18/0.97 | 2.52/0.77 | 2.01/0.61 | 1.42/0.43 |
Maximum Average Attenuation @150KHz | dB/km / dB/kft | 11.4/3.47 | 8.3/2.53 | 6.2/1.89 | 4.4/1.34 |
Maximum Average Attenuation @772KHz | dB/km / dB/kft | 24.3/7.4 | 19.4/5.9 | 15.4/4.7 | 10.8/3.3 |
Maximum Average Attenuation @1000KHz | dB/km / dB/kft | 27.1/8.25 | 21.4/6.52 | 17.5/5.33 | 12.8/3.89 |
Dielectric Strength | |||||
Conductor to Conductor (3secs) | V DC | 2400 | 3000 | 4000 | 5000 |
Conductor to Conductor (3secs) | V DC | 10000 | 10000 | 10000 | 10000 |
Minimum EL Far-end Cross-talk-Mean Power Sum | |||||
@150KHz | dB/305m / dB/kft | 61 | 63 | 63 | 65 |
@772KHz | dB/305m / dB/kft | 47 | 49 | 49 | 57 |
@1.6MHz | dB/305m / dB/kft | 41 | 42 | 43 | 44 |
@3.15MHz | dB/305m / dB/kft | 35 | 37 | 37 | 39 |
@6.3MHz | dB/305m / dB/kft | 29 | 31 | 31 | 33 |
Minimum Far-end Cross-talk-Worst Pair Power Sum | |||||
@150KHz | dB/305m / dB/kft | 57 | 57 | 57 | 59 |
@772KHz | dB/305m / dB/kft | 43 | 43 | 43 | 45 |
@1.6MHz | dB/305m / dB/kft | 37 | 37 | 37 | 39 |
@3.15MHz | dB/305m / dB/kft | 31 | 31 | 31 | 33 |
@6.3MHz | dB/305m / dB/kft | 25 | 25 | 25 | 27 |
Minimum Near-end Cross-talk-Mean Power Sum | |||||
@150KHz | dB/305m / dB/kft | 58 | 58 | 58 | 58 |
@772KHz | dB/305m / dB/kft | 47 | 47 | 47 | 47 |
@1.6MHz | dB/305m / dB/kft | 43 | 43 | 43 | 43 |
@3.15MHz | dB/305m / dB/kft | 38 | 38 | 38 | 38 |
@6.3MHz | dB/305m / dB/kft | 34 | 34 | 34 | 34 |
Minimum Near-end Cross-talk-Worst Pair Power Sum | |||||
@150KHz | dB/305m / dB/kft | 53 | 53 | 53 | 53 |
@772KHz | dB/305m / dB/kft | 42 | 42 | 42 | 42 |
@1.6MHz | dB/305m / dB/kft | 38 | 38 | 38 | 38 |
@3.15MHz | dB/305m / dB/kft | 33 | 33 | 33 | 33 |
@6.3MHz | dB/305m / dB/kft | 29 | 29 | 29 | 29 |
Nominal Insulation Thickness | mm | 0.175 | 0.2 | 0.26 | 0.3 |
Nominal Insulated Conductor Diameter | mm | 0.75 | 0.9 | 1.15 | 1.5 |