Resources

Cable glossary

The terms you will meet on wire boxes, cable drums and price lists, explained in plain language.

1100 V grade: The voltage rating of house wires and LT cables. It is far above the 230 V or 415 V they actually carry, which gives a wide safety margin for the insulation.
2X: In cable type codes, XLPE insulation. See the guide to cable type codes.
A (in cable codes): Aluminium conductor, as in A2XY. A code with no A has a copper conductor.
Armour: A layer of steel or aluminium wire or strip that protects a cable from crushing and digging. W is steel round wire, F is steel flat strip, Wa and Fa are their aluminium equivalents.
ATCAnnealed tinned copper: Copper that has been heat-treated to make it soft and flexible, then coated with tin to resist corrosion. Used in solar cable, drain wires and telephone cable.
BISBureau of Indian Standards: The national standards body. It writes standards such as IS 694 and licenses manufacturers to use the ISI mark.
CAT6: A category of twisted-pair data cable for Ethernet networks, with four pairs and tighter twists than CAT5e. Newtek CAT6 is unshielded (UTP) with a star separator.
CCSCopper-clad steel: A steel conductor with a copper skin. Used in some RG6 coaxial cables, where the high-frequency signal travels mostly in the outer copper.
Class 5 conductor: A flexible conductor made of many fine strands, defined in IS 8130. Class 1 is solid, class 2 is stranded, class 5 is flexible and class 6 is extra flexible.
CM/L number: The BIS licence number printed next to the ISI mark. You can check it in the BIS Care app.
CPRICentral Power Research Institute: A government test laboratory for electrical equipment, which certifies properties such as insulation resistance and anti-termite treatment.
Drain wire: A bare wire laid against the foil screen of an instrumentation cable, so the screen can be connected to earth easily.
E / UE: Earthed and unearthed systems. HT cable voltage grades are given for each, for example 6.6 kV (UE) / 11 kV (E).
EN 50618: The European standard for cables used in photovoltaic (solar) systems.
FRFlame retardant: Insulation that does not keep burning once the source of the flame is removed, so a fault does not spread along the cable.
FR-LSHFlame retardant, low smoke and halogen: Flame-retardant PVC that also gives off much less smoke and acid gas when it burns. Newtek Fire Free is FR-LSH.
HFFRHalogen-free flame retardant; also FRHF, LSZH: Insulation with no chlorine or other halogens, so it releases no corrosive gas in a fire. Newtek Home Shield is halogen-free.
HR / HRFRHeat resistant, flame retardant: PVC formulated to withstand higher conductor temperatures than ordinary PVC, combined with flame retardance. Newtek Shock Free is HRFR.
HSN 8544: The tariff code for insulated wire and cable, used on GST invoices.
HT / LT: High tension and low tension. LT cables are rated up to 1100 V; HT cables run from 3.3 kV upwards.
IACSInternational Annealed Copper Standard: The reference for conductivity. 100% IACS is the conductivity of a standard annealed copper sample; good modern copper measures slightly above it.
Insulation resistance: How well the insulation stops current leaking from the conductor. High insulation resistance (HIR) compounds keep leakage low as the wire ages.
IS 694: The Indian Standard for PVC insulated cables for working voltages up to and including 1100 V. House wires and flexible cables are made to it.
IS 7098: The Indian Standard for XLPE insulated cables. Part 1 covers up to 1100 V; Part 2 covers 3.3 kV to 33 kV.
IS 8130: The Indian Standard for conductors in insulated cables. It sets the maximum resistance for each conductor size and class.
IS 17048: The Indian Standard for halogen-free flame-retardant cables.
ISI mark: The certification mark of the Bureau of Indian Standards, showing a product is made under licence to the stated Indian Standard.
Jelly filled: Cable with a water-blocking gel inside, so moisture cannot travel along it. Used for outdoor and underground CCTV and telephone runs.
Module (M): A unit of width on modular switch plates. A 2M plate holds two one-module switches or one two-module socket.
Oxygen index: The minimum oxygen concentration a material needs to keep burning. Air is about 21% oxygen, so a material with a higher index puts itself out in normal air.
PoEPower over Ethernet: Sending power and data over the same network cable, common for IP cameras and Wi-Fi access points.
RG59, RG6, RG11: Coaxial cable types. RG59 is thinnest and suits short CCTV runs, RG6 is the usual cable TV and DTH cable, and RG11 has the lowest loss for long runs.
RoHS: Restriction of Hazardous Substances, a limit on lead, mercury, cadmium and other substances in electrical products.
SP / DP: Single pole and double pole. A DP switch or MCB breaks both phase and neutral.
Sq mm: Square millimetres, the nominal cross-sectional area of the conductor. It sets how much current the wire can carry.
UTPUnshielded twisted pair: Data cable that relies on the twist of each pair, rather than a foil screen, to reject interference.
Voltage drop: The voltage lost along a cable because of its resistance. Long runs and thin wire increase it. Try the voltage drop calculator.
XLPECross-linked polyethylene: An insulation used in power cables. It handles higher conductor temperatures than PVC and has excellent electrical properties.
XLPOCross-linked polyolefin: A halogen-free, UV-resistant insulation and sheath used in solar cable.