Techo fotovoltaico - energía verde

10 March, 2020

Electrical Cable Types, Sizes, and Installation

An electrical cable has the purpose of transporting electrical energy from one point to another. Depending on their final application, cables can have different configurations, always basing their design on national and international regulations.

Electrical cable Voltage

An electric cable is measured in volts and, depending on these, they are categorized into one group or another:

Types of electrical cable by their use

Low voltage cables

Cables for electric panels

Flexible cables for wiring electric cabinets. These electric cables are especially suitable for domestic use, for installation in public places and for internal wiring of electrical cabinets, switch boxes and small electrical appliances.

Power cables

Energy cables for industrial facilities and public places. It is common to find power cables in applications for power transmission in all types of low voltage connections, for industrial use and for variable frequency drive (VFD).

Armoured cables

Cables with aluminium or steel reinforcement for installations with risk of mechanical aggression. It is also common to find armoured cables in places where rodents are present, as well as in installations in premises with a risk of fire and explosion (ATEX).

Rubber cables

The use of extra flexible rubber cables is very varied. We can find rubber cables in fixed industrial installations as well as in mobile service. Welding cables should have a rubber sheath, which allows high currents to be transmitted between the welding generator and the electrode.

Halogen-free cables

High Security Halogen Free (LSZH) Cables with low smoke and corrosive gas emission in case of fire are suitable for use in wiring of electrical panels and public places, installations of all kinds in public places, individual derivations, emergency circuits, public distribution networks and also for mobile service.

Fire resistant cables

These cables are specially designed to transmit electrical energy in the extreme conditions that occur during a prolonged fire, guaranteeing supply to emergency equipment such as signalling, smoke extractors, acoustic alarms, water pumps, etc. Their use is recommended in emergency circuits in places with public concurrence.

Control cables

Control cables for fixed or mobile installations should be extremely flexible, as they are mainly designed for small household appliances, for the interconnection of machine parts used for manufacturing, for signalling and control systems, for the connection of motors or frequency converters, for signal transmission where the voltage induced by an external electromagnetic field may affect the transmitted signal or for power supply connections to avoid generating electromagnetic fields.

Instrumentation cables

These are flexible and shielded cables for the transmission of signals between equipment in industrial installations. Especially suitable for optimum data transmission in environments with a high level of electromagnetic interference.

Solar cables

These cables are particularly suitable for connecting photovoltaic panels, and from the panels to the DC to AC inverter. Thanks to the design of their materials and their cover, which is especially resistant to solar radiation and extreme temperatures, they can be installed outdoors with full guarantees.

Special cables

There is a wide variety of electric cables for special installations such as: temporary light garland installations at trade fairs; connections for overhead cranes, hoists and lifts; applications in submerged pumps and drinking water areas such as aquariums, purification systems, drinking water fountains or in swimming pools for lighting, purification and cleaning systems.

Aluminium cables

Aluminium cables for power transmission are suitable for fixed installation indoors, outdoors and/or underground.

Medium Voltage Cables


Medium Voltage Cable type RHZ1 with XLPE insulation, halogen free and non flame and/or fire propagating. They are cables perfectly adapted for the transportation and distribution of energy in Medium Voltage networks.


Medium Voltage cable with HEPR insulation, halogen-free and not flame- and/or fire-propagating Ideal for the transportation and distribution of energy in Medium Voltage networks.


Medium Voltage cable with XLPE insulation, according to American standard. For transportation and distribution of energy in Medium Voltage networks.


Copper and aluminium medium voltage cable for special applications. Especially recommended for installations where there is a risk of presence of oils and chemical agents of the hydrocarbon type or their derivatives.

Top Cable has a wide range of electrical wiring. Do not hesitate to consult our catalogue and find any cable you need:

Download the Top Cable catalogue here.

Components of an electrical cable

Componentes de un cable eléctrico

An electric cable consists of:

Types of electric conductors

Types of insulation for electric cables

The insulation consists of placing an insulating coating on the conductor to prevent current leakage. They are classified into two large groups: thermoplastic and thermoset.

1. Thermoplastic insulation

They are most common in the manufacture of electrical cables are:

2. Thermosetting insulation

The most common are:

Types of metal protections for electrical cables

In some cases, the cables may have metal shields.

Nomenclature of electrical cables according to standards

Each cable has a standard designation. This designation is composed of a set of letters and numbers, each with a specific meaning. This designation refers to a series of product characteristics (materials, nominal tensions, etc.) that facilitate the selection of the most suitable cable for your needs, avoiding possible errors in the supply of one cable by another.

When a cable does not clearly indicate these data, it may be a defective cable, which does not comply with safety regulations or guarantee the cable’s life and proper operation.

Designation according to type of insulation

nomenclatureCable type
RCrosslinked polyethylene (XLPE)
XCross-linked polyethylene (XLPE)
Z1Halogen-free thermoplastic polyolefin
ZHalogen-free thermosetting elastomer
VPolyvinyl chloride (PVC)
SHalogen-free thermosetting silicone compound
DEthylene-propylene elastomer (EPR)

Screen designation, interior lining, armature seat

nomenclatureCable type
C3Copper wire screen, helically arranged
C4Copper shield in the form of a braid, on the assembled insulated conductors.
VPolyvinyl chloride (PVC)
Z1Halogen-free thermoplastic polyolefin

If there is no screen, no inner lining and no armature seat, no letter is used.

Designation of the different types of armor

nomenclatureCable type
FSteel strapping arranged in a helical pattern.
FAAluminium strapping arranged in a helical pattern
FA3Longitudinally corrugated aluminium strip
MSteel wire crown
MAAluminium wire crown

Designation of the outer sheath

nomenclatureCable type
VPolyvinyl chloride (PVC)
Z1Halogen-free thermoplastic polyolefin
ZHalogen-free thermosetting elastomer
NVulcanized chlorinated polymer

Conductor’s designation

nomenclatureCable type
KFlexible copper (class 5) for fixed installations
FFlexible copper (class 5) for mobile services
DFlexible for welding machine cables. When there are no letters on it, the conductor is made of solid copper, class 1 or 2.
ALAL If the conductor is made of aluminium, (AL) is indicated.

Tensión nominal

0,6/1 kVRated voltage 1,000V

Explanation of the number of conductors

nomenclatureCable type
nGSNumber and cross-section of wires, in mm2 , with Yellow/Green conductor
nxSNumber and cross-section of conductors, in mm2 , without conductor Yellow/Green

Cable design rules

The cable design rules are also referenced in the marking of each cable:

Additional data

nomenclatureCable type
CECE CE marking is compulsory for the marketing of the product in the European Community. This marking can be on the product or on the packaging.
Manufacture dateDate of manufacture (YYMMDD). The date of manufacture is usually placed for traceability purposes. Traceability makes it possible to know who, when and where has carried out each stage of the process and with which materials.

You can review concepts through this video that we have prepared:

YouTube video

Dimensioning criteria of electrical conductors

There are two sizing criteria for copper conductors:

Electrical cable measurements

25 mm24Very highCentral air conditioning and industrial equipment..
16 mm26High airConditioners, electric stoves and electric power connections.
10 mm28Medium highRefrigerators and dryers.
6 mm210MediumMicrowave and blenders
4 mm212MediumLighting
2.5 mm214UnderLamps
1.5 mm216Very lowThermostats, bells or security systems.

Types of colours in electrical cables and their meaning

The colours of the electrical cables are governed by the International Electrical Commission Standard IEC 60446. For the identification of the conductors, the following colors are allowed: black, brown, red, orange, yellow, green, blue, violet, gray, white, pink and turquoise.