Foam Skin Insulated & LAP Sheathed Jelly Filled Cables to IEC60708

Application

The IEC60708 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. A figure-8 self support option is offered for aerial installation.

Standards

• IEC 60708

Construction

Conductors
Solid annealed bare copper, 0.4/0.5/0.6/0.63/0.8/0.9 mm as per class 1 of IEC 60228 & ASTM B-3

Insulation
Foam Skin which is a composite polyethylene insulation made of an inner cellular layer and an outer solid skin, 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
Twisted Pairs

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 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 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 ensure a barrier against water vapor. In cables with more than 200 pairs, the aluminum tape may be corrugated for improved cable flexibility

Filling (optional)
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/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 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 0.2/0.5mm thick steel tape is coated with a copolymer and applied with an overlap. 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	0.6	0.63	0.8	0.9
Conductor Gauge Size	AWG	26	24	-	22	20	19
Conductor Size	mm2	0.126	0.196	0.283	0.312	0.5	0.636
Maximum Average Conductor Resistance @20°C	Ω/km	143	91	63	58	34.6	28
Minimum Insulation Resistance @500V DC	MΩ.km	5000	5000	5000	5000	5000	5000
Maximum Average Mutual Capacitance @800Hz	nF/km	53	53	56	56	59	59
Maximum Individual Mutual Capacitance @800Hz (for 99% cases)	nF/km	60	60	60	60	64	64
Maximum Individual Capacitance Unbalance @800Hz pair-to-pair	pF/500m	250	250	250	250	160	160
Maximum Individual Capacitance Unbalance @800Hz pair-to-pair ( for 95% cases)	pF/500m	150	150	150	150	100	100
Maximum Individual Capacitance Unbalance @800Hz pair-to-ground	pF/500m	1700	1700	1700	1700	1700	1700
Maximum Individual Capacitance Unbalance @800Hz pair-to-ground ( for 95% cases)	pF/500m	1000	1000	1000	1000	1000	1000
Maximum Conductor Loop Resistance @20°C	Ω/km	300	192	130	114	73	60
Impedance @1KHz	Ω	994	796	665	660	500	445
Impedance @100KHz	Ω	147	134	127	125	124	122
Impedance @512KHz	Ω	120	118	117.5	117	116.5	116
Impedance @1MHz	Ω	117	115	114.5	114	113.5	113
Maximum Average Attenuation @0.8KHz	dB/km	1.64	1.30	1.1	1.04	0.9	0.74
Maximum Average Attenuation @1KHz	dB/km	1.68	1.35	1.14	1.08	0.93	0.76
Maximum Average Attenuation @3KHz	dB/km	3.18	2.52	2.3	2.01	1.74	1.42
Maximum Average Attenuation @150KHz	dB/km	11.4	8.3	7.2	6.2	5.7	4.4
Maximum Average Attenuation @772KHz	dB/km	24.3	19.4	17.4	15.4	13.1	10.8
Maximum Average Attenuation @1000KHz	dB/km	27.1	21.4	18.5	17.5	13.7	12.8
Dielectric Strength
Conductor to Conductor (1min)	V DC	500	500	500	500	500	500
Conductor to Screen (1min)	V DC	1000	1000	1000	1000	1000	1000
Nominal Insulation Thickness	mm	0.175	0.20	0.25	0.26	0.3	0.3
Nominal Insulated Conductor Diameter	mm	0.75	0.90	1.1	1.15	1.4	1.5

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

Foam Skin Insulated and LAP Sheathed Jelly Filled 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
TP708-02YSF(L)2Y-10P04	10	1.5	9.0	82
TP708-02YSF(L)2Y-20P04	20	1.5	10.0	120
TP708-02YSF(L)2Y-30P04	30	1.5	11.0	161
TP708-02YSF(L)2Y-50P04	50	1.5	14.0	239
TP708-02YSF(L)2Y-70P04	70	1.5	15.0	315
TP708-02YSF(L)2Y-100P04	100	1.5	18.0	434
TP708-02YSF(L)2Y-150P04	150	1.5	21.0	630
TP708-02YSF(L)2Y-200P04	200	1.8	24.0	824
TP708-02YSF(L)2Y-300P04	300	1.8	29.0	1195
TP708-02YSF(L)2Y-400P04	400	1.8	32.0	1556
TP708-02YSF(L)2Y-500P04	500	2.0	36.0	1921
TP708-02YSF(L)2Y-600P04	600	2.0	39.0	2282
TP708-02YSF(L)2Y-800P04	800	2.5	44.0	2987
TP708-02YSF(L)2Y-900P04	900	2.5	46.0	3364
TP708-02YSF(L)2Y-1000P04	1000	2.5	49.0	3712
TP708-02YSF(L)2Y-1200P04	1200	2.8	53.0	4411
TP708-02YSF(L)2Y-1500P04	1500	2.8	59.0	5483
TP708-02YSF(L)2Y-1800P04	1800	3.2	64.0	6567
TP708-02YSF(L)2Y-2100P04	2100	3.2	69.0	7626
TP708-02YSF(L)2Y-2400P04	2400	3.5	73.0	8663
TP708-02YSF(L)2Y-2700P04	2700	3.5	77.0	9697
TP708-02YSF(L)2Y-3000P04	3000	3.5	81.0	10729

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