Telephone Cables

 Solid PE Insulated & LAP Sheathed Air Core Cables to IEC 60708

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. An armoured option is offered for direct burial installations. A figure-8 self support option is offered for aerial installation

Standards

Telephone Cables

 Telephone Cables

  
• IEC 60708

Construction

Conductors: Solid annealed bare copper, 0.4/0.5/0.6/0.8mm as per BS 6360/IEC 60228 Class 1

Insulation: Solid polyethylene as per IEC 60708/BS EN 50290-2-23/BS 6234/ASTM D 1248/NFC 32-060/VDE 0207

Twisted Pairs: Insulated conductors are twisted into pairs with varying lay length to minimize crosstalk

Cabling Element: Pairs or Quads

Cable Core Assembly: Cables with 100 pairs or less are composed of 10-pair sub-units; cables with over 100 pairs are composed of 50 or 100-pair units. Any extra pairs form a separate unit. Units are identified by colour coded binders. Standard construction is per IEC 60708 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 aluminium tape (0.15mm) coated with PE-copolymer on one or both sides is applied longitudinally with overlap over the cable core to provide electrical shielding coverage and ensure 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 BS 6234/IEC 60708/ASTM D 1248, 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 in large pair cables

Continuity Wire (optional): 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 steel tape is 0.2/0.5mm thick, being coated with a PE copolymer and applied with an overlap. An outer polyethylene sheath is applied over the armour

Self-Support Cables
Per CW 1252. 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

0.6

0.8

Conductor Gauge Size

AWG

26

24

-

20

Conductor Size

mm2

0.126

0.196

0.283

0.5

Maximum Average Conductor Resistance @20°C

Ω/km

143

91

63

34.6

Minimum Insulation Resistance @500V DC

MΩ.km

5000

5000

5000

5000

Maximum Average Mutual Capacitance @800Hz

nF/km

53

53

56

59

Maximum Individual Mutual Capacitance @800Hz (for 99% cases)

nF/km

60

60

60

64

Maximum Individual Capacitance Unbalance @800Hz pair-to-pair

pF/500m

250

250

250

160

Maximum Individual Capacitance Unbalance @800Hz pair-to-pair (for 95% cases)

pF/500m

150

150

150

100

Maximum Individual Capacitance Unbalance @800Hz pair-to-ground

pF/500m

1700

1700

1700

1700

Maximum Individual Capacitance Unbalance @800Hz pair-to-ground
(for 95% cases)
pF/500m 1000 1000 1000 1000

Maximum Conductor Loop Resistance @20°C

Ω/km

300

192

130

73

Impedance @1KHz

994

796

665

500

Impedance @100KHz

147

134

127

124

Impedance @512KHz

120

118

117.5

116.5

Impedance @1MHz

117

115

114.5

113.5

Maximum Average Attenuation @0.8KHz

dB/km

1.64

1.30

1.1

0.9

Maximum Average Attenuation @1KHz

dB/km

1.68

1.35

1.14

0.93

Maximum Average Attenuation @3KHz

dB/km

3.18

2.52

2.3

1.74

Maximum Average Attenuation @150KHz

dB/km

11.4

8.3

7.2

5.7

Maximum Average Attenuation @772KHz

dB/km

24.3

19.4

17.4

13.1

Maximum Average Attenuation @1000KHz

dB/km

27.1

21.4

18.5

13.7

Dielectric Strength          
Conductor to Conductor (1min) V DC 500 500 500 500
Conductor to Screen (1min) V DC 1000 1000 1000 1000

Nominal Insulation Thickness

mm

0.175

0.20

0.25

0.3

Nominal Insulated Conductor Diameter

mm

0.75

0.90

1.1

1.4

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


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 IEC 60708 given in Colour Code Chart

Dimensions And Weight
Solid PE Insulated & LAP Sheathed Air Core Cable to IEC 60708

Cable Code

Number
of
Pairs

Nominal Sheath
Thickness
mm

Nominal Overall
Diameter
mm

Nominal
Weight
kg/km

0.4mm Conductor, 0.75mm Insulated Wire

TP708-2Y(L)2Y-10P04

10

1.5

9

71

TP708-2Y(L)2Y-20P04

20

1.5

10

107

TP708-2Y(L)2Y-30P04

30

1.5

11

143

TP708-2Y(L)2Y-50P04

50

1.5

13

211

TP708-2Y(L)2Y-70P04

70

1.5

15

278

TP708-2Y(L)2Y-100P04

100

1.5

17

380

TP708-2Y(L)2Y-150P04

150

1.5

21

548

TP708-2Y(L)2Y-200P04

200

1.8

23

708

TP708-2Y(L)2Y-300P04

300

1.8

28

1034

TP708-2Y(L)2Y-400P04

400

1.8

31

1358

TP708-2Y(L)2Y-500P04

500

2.0

35

1703

TP708-2Y(L)2Y-600P04

600

2.0

38

2016

TP708-2Y(L)2Y-800P04

800

2.5

43

2639

TP708-2Y(L)2Y-900P04

900

2.5

46

2961

TP708-2Y(L)2Y-1000P04

1000

2.5

48

3264

TP708-2Y(L)2Y-1200P04

1200

2.8

52

3873

TP708-2Y(L)2Y-1500P04

1500

2.8

58

4819

TP708-2Y(L)2Y-1800P04

1800

3.2

63

5777

TP708-2Y(L)2Y-2100P04

2100

3.2

68

6731

TP708-2Y(L)2Y-2400P04

2400

3.5

72

7645

TP708-2Y(L)2Y-2700P04

2700

3.5

76

8556

TP708-2Y(L)2Y-3000P04

3000

3.5

80

9466

 

 

 

 

 

 

 

 

 

 

 

 

 


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