Frequently asked cables questions

Frequently asked questions

What is the difference between the Power & Control Cables?

Power Cables - No. of Cores 2,3, 3 1/2 & 4 Core

Control Cables - Upto 63 Cores or above

Standards Applicable for both - IS-694 & IS-1554 .

What is the difference between Unsheathed & Sheathed Single Core Cable as per IS-694?

Unsheathed - Only Core Insulation will be done and there will be no Sheathing.

Sheathed - Sheathing will be done on Core Insulation.

What is the difference between Control & Instrumentation Cable?

Control Cables – They are generally Core Constructed.

Instrumentation Cables – They are generally Pair Constructed with Shielding.

What is the difference between Thermocouple & Instrumentation Cable?

Conductor Material is Different for both.

What is the difference between Armoured & Unarmoured Cable?

a. Armour.

b. Inner Sheath will be provided for Armoured Cable before Armouring.

What is a Co-Axial Cable?

This type of cable is used for Very High Frequency (V.H.F.) Applications.

What are the Different types of PVCs and what are its normal working temperatures?

a. Insulation - PVC General Purpose (Type A) - 70 Deg.C

HR PVC (Type C) - 90 Deg.C

b. Sheath Material PVC St1 - 70 Deg. C

HR PVC / PVC St2 - 90 Deg. C

FRLS PVC - 105 Deg. C.

What is the Voltage Grade?

Low Voltage Grade -- upto and including 1.1 KV

High Voltage Grade -- above 1.1 KV

Number of Strands for:

a. Solid Conductor - One

b. Multistrand - either 3 or 7

c. Flexible - No of Strands above 7

- Dia of Strands upto 0.3 mm .

What are the other Sizes of Strands in case of flexible Conductor?

0.1mm, 0.15mm, 0.2mm & 0.3mm.

Dia of Strands for 1.5 Sq.mm can be:

a. Incase of 7 Strands - 7/0.52

b. Incase of 0.3 mm dia each - 21 Strands

c. Incase of 0.2 mm dia each - 48 Strands.

What is the Core / Pair Identification incase of LDPE Insulated Cable?

By Colour or By Number printed Al-Mylar Tape / Polyster Tape.

What is the Purpose of Screening?

To reduce the interference by nearby sources.

What are the different types of Screenings?

a. Al-Mylar / Cu-Mylar Tape

b. ATC or ABC Braiding.

Which type of Screening is Cheaper?

AL-Mylar.

Noise in Instrumentation Cable is called?

Reduction of Accuracy of Signal passing through the Cable.

What is Thermocouple Extention Cable?

Thermocouple Element material & Thermocouple Cable Conductor materials are same.

What is Thermocouple Compensating Cable?

If the Electrical properties of the Conductor material used for the Thermocouple Cable is almost similar to that of Thermocouple element material it is called Compensating Cable.

Why there is no Compensating Cables for Tx, Jx & Ex Type T/C Cables?

This Thermocouple Element material itself is cheaper.

What will be the Normal Insulation Thickness for Telephone Cables?

a. Core Insulation - 0.2, 0.3 mm

b. Sheath - 0.5 to 1.2 mm.

What is the difference between RTD / Instrumentation Cable?

RTD Cables will be Triad Constructed.

Instrumentation Cables are Pair constructed.

What are the normal sizes of Control Cables?

1.5 & 2.5 Sq.mm

What will be the normal Conductor sizes for instrumentation / RTD Cables?

0.5, 0.75, 1.0, 1.5 & 2.5 Sq.mm

Thermocouple Cable Conductor normal sizes for:

a. Single pair - 16 AWG (1.295 mm dia)

b. Multi pair - 20 AWG (0.813 mm dia)

What are the standards for T/C Cables?

IS-8784, ANSI MC 96.1 (Please refer our Catalogue for other Standards.)

What is the Temperature Tolerance (+/- deg. C) allowable for Thermocouple cables for T/C Cables?

a. IS 8784 +/- 3 Deg. C

b. ANSI MC 96.1 +/- 2.2 Deg. C

Colour code as per IS 1554 for Core constructed Cables ?

a. Upto 5 Cores by different colours i.e for 2 Cores Red & Black, for 3 Cores Red, Yellow & Blue, for 4 cores Red, Yellow, Blue & Black, for 5 Cores Red, Yellow, Blue, Black & Grey.

b. Above 5 Cores : One Core Yellow and One Core Blue remaining Grey in each layer (or) any single colour with numbers printed.

For above 5 Cores Grey with number printing is our normal practice.

What are the 3 types of Braided (Metal Braiding) Cables can manufactured?

a. Annealed Tinned Copper Braided Cables.

b. Annealed Bare Copper Braided Cables.

c. Nickle Plated Copper Braided cables

d. G.I. Braided Cables.

What is the Temperature with standability of PTFE & Fibre Glass?

PTFE - 250 Deg.C,

FG Cables 400 Deg.C

by: Prigas Wibawa