Instrument Signal Cables

The company manufactures and stocks a wide range of Screened Instrumentation Cables needed for signaling systems, control and instrument circuits. These cables report and monitor process variables ranging from transducers to environmental controls and computer inputs.
The carefully produced stranded copper conductors used in the cable maintain high system accuracy and sensitivity. Maximum rejection of electro magnetic noise is achieved by twisting the insulated conductors. Twisting causes the noise to be cancelled in adjacent sections of the wire.

Maximum electrostatic noise rejection is achieved by shielding the cable with aluminium-mylar tape. An overall shield is normally provided and in critical applications an individual shield over each pair or triad is also provided. A minimum of 25% overlap of the shield ensures 100% coverage even when the cable is flexed. The drain wire under the shield provides continuous low resistance path to ground and simplified hook-up at grounding terminals. The cables can also be provided with copper braid screening.

Ease of installation is another major benefit of these cables. Individual cores, pairs, triads or quads are colour coded and or number printed. A pair of communication wires can also be provided. The cables are available in a wide range of insulation and jacket materials, the most popular being PVC, Polyethylene, HR PVC, FRLS PVC, ZHLSF, Silicone, EPR & CSP rubber, Teflon.

The detailed construction, conductor sizes and electrical characteristics are as mentioned below. The company also manufactures custom designed cables to meet the specific requirements of individual customer applications.

Construction:

Conductor

Bare / tinned electrolytic annealed copper conductor. Solid, stranded or flexible confirming to BS 6360 and IS 8130. Refer Table 1 for details.

Insulation :

PVC or HR PVC insulation in accordance with IS 5831. Polyethylene insulation in accordance with BS 6234 / IS 6474.

Twisting and Laying :

Required numbers of cores are laid up in case of multicore core cables. Individual pairs, triads or quads are formed by uniformly twisting the insulated cores with short lay lengths, prior to laying.

Core Identification :

Cores can be colour coded or number printed for easy identification. In case of multi pair cables one core in each pair is number printed in words as well as in figures at short intervals of 50mm or a numbered polyester tape is provided over each pair.

Overall Screen :

After final lay up of the complete cable an overall screen of aluminium-polyester tape is applied along with 0.5 sqmm multi stranded annealed tinned copper (ATC) drain wire in continuous electrical contact with aluminium side of the tape. Tinned copper braid screening can also be provided.

Individual & Overall Screen :

Individual pairs, triads or quads are screened by aluminium-polyester tape along with 0.5 sqmm ATC drain wire and overall screened by aluminium-polyester tape as mentioned above. Tinned copper braid screening can also be provided.
In case of individually screened cables for critical applications an extruded isolation sheath can also be provided over the individual screens.

Assembly Binder :

After final assembly a non-hygroscopic polyester tape is provided to act as a binder as well as a bedding for the outer screening in all cables.

Armour:

Galvanized steel round wire or strip armour in accordance with BS 5308 / IS 1554 respectively. The armour wire and strip confirms to IS 3975. If required, G.I square interlock armour or G.I / S.S wire braid armour can also be provided.

Inner & Outer Sheath :

PVC, HR, FRLS PVC or ZHLSF sheath in accordance with IS 5831 can be provided. U.V stabilized Polyethylene sheath can also be provided for hazardous areas. A blue colour outer sheath for intrinsically safe areas can be provided on request. A pair of communication wires can be provided if desired.

DETAILS OF CONDUCTOR & INSULATION

Nominal
Cond.
Area

Nominal
Cond.
Strands

Approx.
Cond.
Diameter

Max Cond Res. @ 20°C

Nominal
Insulation
Thick.

Nominal
Core
Diameter

Bare
Copper

Tinned
Copper

Sqmm

No./mm

mm

ohms/km

ohms/km

mm

mm

0.5

1/0.8

0.80

36.0

36.7

0.5

1.80

0.5

7/0.3

0.90

36.0

36.7

0.6

2.10

0.5

16/0.2

1.00

39.0

40.1

0.6

2.20

0.75

1/0.98

1.00

24.5

24.8

0.6

2.20

0.75

7/0.37

1.10

24.5

24.8

0.6

2.30

0.75

24/0.2

1.20

26.0

26.7

0.6

2.40

1.00

1/1.13

1.10

18.1

18.2

0.6

2.30

1.00

7/0.43

1.30

18.1

18.2

0.6

2.50

1.00

32/0.2

1.40

19.5

20.0

0.6

2.60

1.5

1/1.38

1.40

12.10

12.2

0.6

2.60

1.5

7/0.53

1.60

12.10

12.2

0.6

2.80

1.5

48/0.2

1.60

13.30

13.7

0.6

2.80

2.5

1/1.78

1.80

7.41

7.56

0.6

3.00

2.5

7/0.67

2.00

7.41

7.56

0.6

3.20

2.5

80/0.2

2.00

7.98

8.21

0.6

3.20

ELECTRICAL CHARACTERISTICS

Sl.

Parameters

Units

PVC Insulated

P.E Insulated

1.

Max. Conductor Resistance

Ohms/km

Refer Table 1

2.

Minimum Insulation Resistance

Mohms/km

25

5000

3.

Max. Mutual Capacitance @1KHz Core to core

pF/mtr

250

75

For 1.5mm²

250

85

4.

Max. Capacitance, core to screen

pF/mtr

400

115

5.

Max. L/R Ratio

µH/ohm

25

25

For 1.5mm²

40

40

For 2.5mm²

70

70

6.

Max. Mutual Inductance

mH/km

1.0

7.

High Voltage Tests:

Spark Test

Volts

4000

Core to Core

Volts

1500

Core to Screen

Volts

1000

Screen to Armour

Volts

500

Screen to Screen (optional)

Volts

125