Wire and cable codes
As we know, wires and cables are used to distribute the generated electric energy. A wire or cable is a conductor that can pass electric current or electrical signals and at the same time is insulated from its surroundings so that it does not get into trouble in different working conditions. The type of this conductor, wire, and cable codes are always displayed as characteristic codes.
Cable and wire are different in terms of conductor type, insulation, installation conditions, etc. A wire is a conductor usually single-stranded and covered with an insulating layer. Still, a cable may consist of several conductors insulated from each other and the ground. In general, it can be said that all cables and wires consist of two main parts, an insulator, and a conductor, each of which is used in a special way in the building.
The conductor part forms the main core of the wire and cable and is responsible for the transmission of electricity. The conductor is usually made of copper and aluminum in different shapes and cross-sections. The conductor part may be used in wire and cable in the form of exposed, semi-expanded, wire and in circular and sector forms. Types of conductors are displayed with the following abbreviations:
r : Circular cross-section
s : Triangular cross-section
e : Single-strand conductor or wire
m : Conductor multi-stranded or sprinkler
The insulation part of wire and cable is responsible for protecting the conductor against connecting to other parts and it is stretched as a coating on the entire surface of the conductor and insulates it from the surrounding environment. This cover is made of different types, which can be referred to as oil-soaked paper, rubber, and plastic insulation.
In cables, after insulating the conductors from each other, they are placed in another insulating cover called a sheath. This cover is also made in different types of cables. A simple type of sheath is only a plastic cover, but in special cables, it may be made with metal layers. This metal layer, which is made of different materials, is called armor. The armor is placed under the sheath and is responsible for protecting the cable against mechanical stress.
General points about wire:
- Wires are usually made of copper and a layer of PVC insulation.
- They are made up to 750 volts voltage and up to 240 mm square cross-section.
- They are installed in electrical panels and fixed installations and need protection against moisture.
- In facilities, they should be used inside the duct or pipe.
- It is not allowed to use the wire inside or on the surface without the mentioned protections.
General points about cable:
- Cables usually consist of a number of conductors that are insulated from each other and the environment.
- High voltage cables up to 380kV voltage and up to 1000 mm square cross-sections are made.
- Under certain conditions, the cable can be installed directly in the soil, water, or on surface.
Wire and cable identification letters:
According to the German VDE standard, special letters are used to identify and name wires and cables, which are referred to as wire and cable characteristic codes. The table below describes these symptoms.
|N||Copper cable or wire made according to VDE|
|NA||Aluminum cable or wire made according to VDE|
|Y||(far beam insulation or PVC) (the first Y in the row of letters|
|H||A sign of metallized sheet wrapped around the cable to limit the magnetic field|
|B||steel strip protection (steel bandage)|
|R||Steel protection of wire strip (armor made of tin-plated steel wire)|
|F||Armor of tin-plated steel flat wire (armored cable with flat wire)|
|Gb||Shaped steel strip protection, spiral steel belt to tighten F,R|
|C||In low-pressure cables, the mark is the zero wire, which is wrapped around the insulated tube of three other wires, and in high-pressure cables, the mark is the protection wire or zero wire.|
|CW||A sheath of thin copper wires that covers the cable in a wavy manner and a thin copper belt spirally holds them (concentric copper wire with a spiral copper strip)|
|T||Holding wire in aerial cables made of approved steel|
|Y||Far beam insulation or PVC (the second Y in the row of letters)|
|A||Double outer sheath|
|E||Cable with three lead sheaths|
|S||Copper shield of a wide but thin strip that wraps around the insulation of the wire (instead of H)|
|SE||Copper shielding in multi-core cables around each wire to limit the magnetic field (instead of H)|
|J||Cable with a string in green and yellow|
|re||Single strand round wire|
|rm||Multi-stranded round wire|
|se||Single-strand sector wire|
|sm||Multi-stranded sector wire|
|AB||single strand wire|
|MH||Multi-core cable with conductive conductor|