Telephone Cables | ||||||||||||
Foam Skin Insulated & LAP Sheathed Jelly Filled Cables to RUS(REA) PE-89
Application
The cables are designed for use in access or trunk networks, from telephone exchange to subscriber area. The cables are suitable for installation in ducts, direct burial in the ground and also for aerial installation with integral suspension strand. Jelly filled option is for subscriber’s cables installed underground or along the edge of pavement. An armoured option is offered for direct burial installations where additional mechanical or rodent protection is required. A figure-8 self support option is offered for aerial installation.
Standards
• RUS(REA) PE-89 (RUS 7 CFR 1755.890)
Construction
Conductors
Solid annealed bare copper, 0.4/0.5/0.63/0.9mm as per ASTM B-3/class1 of IEC 60028
Insulation
Foam Skin which is a composite polyethylene insulation made of an inner cellular layer and an outer solid skin 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 of 25 pairs or less are assembled into cylindrical core. Cables larger than 25 pairs are assembled into units, which are then used to form the core Units are identified by colour coded binders. Standard construction is per RUS(REA) PE-89 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 corrugated copolymer coated aluminium tape (0.2mm/8mil) is applied directly over the cable core to provide 100% electrical shielding coverage and ensure 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 ASTM D 1248/IEC 60708, being able to withstand exposure to sunlight,temperature variations, ground chemicals and other environmental contaminants
Ripcord(optional)
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
Corrugated copolymer coated steel tape armour (0.15mm/6mil) is applied with an overlap over an optional inner polyethylene 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
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 |
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 |
48.5-54.0 /14.8-16.5 |
48.5-54.0 /14.8-16.5 |
48.5-54.0 |
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 |
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 |
Ω/km / Ω/mile |
300/482 |
192/309 | 114/183.6 | 60/96.4 |
|
Ω |
994 |
796 | 660 | 445 |
|
Ω |
147 |
134 | 125 | 122 |
|
Ω |
120 |
118 | 117 | 116 |
|
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 Screen (3secs) |
V DC |
10000 |
10000 | 10000 | 10000 |
Minimum EL Far-end Cross-talk-Mean Power Sum | |||||
dB/305m / dB/kft |
61 |
63 |
63 |
65 |
|
dB/305m / dB/kft |
47 |
49 |
49 |
57 |
|
dB/305m / dB/kft |
41 |
42 |
43 |
44 |
|
dB/305m / dB/kft |
35 |
37 |
37 |
39 |
|
dB/305m / dB/kft |
29 |
31 |
31 |
33 |
|
Minimum Far-end Cross-talk-Worst Pair Power Sum | |||||
dB/305m / dB/kft |
57 |
57 |
57 |
59 |
|
dB/305m / dB/kft |
43 |
43 |
43 |
45 |
|
dB/305m / dB/kft |
37 |
37 |
37 |
39 |
|
dB/305m / dB/kft |
31 |
31 |
31 |
33 |
|
dB/305m / dB/kft |
25 |
25 |
25 |
27 |
|
Minimum Near-end Cross-talk-Mean Power Sum | |||||
dB/305m / dB/kft |
58 |
58 |
58 |
58 |
|
dB/305m / dB/kft |
47 |
47 |
47 |
47 |
|
dB/305m / dB/kft |
43 |
43 |
43 |
43 |
|
dB/305m / dB/kft |
38 |
38 |
38 |
38 |
|
dB/305m / dB/kft |
34 |
34 |
34 |
34 |
|
Minimum Near-end Cross-talk-Worst Pair Power Sum | |||||
dB/305m / dB/kft |
53 |
53 |
53 |
53 |
|
dB/305m / dB/kft |
42 |
42 |
42 |
42 |
|
dB/305m / dB/kft |
38 |
38 |
38 |
38 |
|
dB/305m / dB/kft |
33 |
33 |
33 |
33 |
|
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 |
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