General electrical cables indications

General electrical cables indications

Italian national cables, harmonized cables, main CEI standards, identification of cable cores, types of installation

Electrical cables form an essential part of electrical infrastructure around the world. They are used for the safe and efficient transport of electricity in various sectors, from industrial applications to energy distribution networks and domestic systems. The correct selection, installation and management of electrical cables are essential to ensure the safety, reliability and efficiency of electrical systems.

The reason for this guide

This guide was created by Itieffe to offer a comprehensive overview of this crucial topic; provides clear and detailed information on a number of aspects relating to electrical cables, including:

1. Italian national cables: information is provided on the specifications of electrical cables produced in Italy, including their standards and reference regulations.
2. Harmonized cables: This section covers electrical cables that meet European harmonized standards, ensuring compliance with safety and performance requirements.
3. Main CEI Standards: the role of the Italian Electrotechnical Committee (CEI) standards in the regulation of electrical cables and in the promotion of best practices is examined.
4. Identification of cable cores: This part explains how to identify and understand the different cores within electrical cables, including conductors, insulation and shielding.
5. Main Laws: The legal and regulatory frameworks that regulate the use of electrical cables are examined, ensuring safety and compliance.
6. Types of laying: This section provides an overview of the different ways of installing electrical cables, such as installing underground, overhead or in ducts.

Conclusions

Understanding these aspects is essential to ensure that electrical cables are used safely and compliantly with regulations, avoiding safety problems and efficiency losses. This guide aims to be a valuable resource for engineers, technicians, designers, installers and anyone involved in managing electrical systems and choosing the most suitable cables for their specific applications.

General electrical cables indications

Italian national cables, harmonized cables, main CEI standards, cable core identification, main laws, types of laying

General electrical cables indications

Index of topics

1	Italian national cables
2	Harmonized cables
3	Main CEI standards
4	Identification of cable cores
5	Types of laying

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1) Italian national cables

Identification system of Italian national cables according to CEI UNEL 35011

Degree of flexibility of the conductor

A	Aluminum conductor
F	Flexible rope
FF	Extremely flexible rope
R	Rigid rope
S	Sectoral chord
U	Single thread

 

Nature and quality of the insulation

E	Thermoplastic polyethylene based insulation
E4	Cross-linked polyethylene at a characteristic temperature of 85 ° C
G	Insulation based on natural and / or synthetic rubber
G7	Insulator based on ethylene propylene rubber at a characteristic temperature of 90 ° C
G9	Insulation based on cross-linked elastomer with low emission of fumes and toxic and corrosive gases at a characteristic temperature of 90 ° C
G10	Insulation based on cross-linked elastomer with low emission of fumes and toxic and corrosive gases at a characteristic temperature of 90 ° C
R	Insulation based on polyvinyl chloride at a characteristic temperature of 70 ° C, quality TI1-TI2
R2	Insulation based on polyvinyl chloride at a characteristic temperature of 70 ° C, quality R2
R7	Insulating compound based on polyvinyl chloride at a characteristic temperature of 90 ° C, quality TI3

 

Screens

H	Metallized paper or aluminum tape screen
H1	Screen with strips or strips or copper wires
H2	Copper braid or braid screen

 

Armature

A	Braid or metal braid armor
F	Armor with cylindrical wires, usually of steel
N	Ribbon armor, usually made of steel
Z	Steel plate armor

 

Nature of the sheath

E	Thermoplastic sheath
E4	Cross-linked polyethylene
G	Natural and / or synthetic rubber sheath
K	Sheath based on polychloropropylene
R	Polyvinyl chloride based sheath
M1	Sheath made from thermoplastic material with low emission of toxic and corrosive fumes and gases
M2	Elastomeric sheath with low development of toxic and corrosive fumes and gases

 

Form of cables

O	Cylindrical shaped cable
D	Flattened shape cable
X	Cores assembled in a visible helix (eg cord)
W	Flat divisible cable

 

Possible supporting organ

S	Main body generally metallic incorporated in the sheath
Y	Textile or metal bearing organ, included between the cores or tied externally to the cable

General electrical cables indications

Example of an identification:

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General electrical cables indications

2) Harmonized cables

Harmonized cable designation system according to CENELEC HD 361 (CEI 20-27)

 

Reference of standards

H	Cable compliant with harmonized standards
A	Nationally recognized cable
N	National type cable

 

Nominal tension

Uo / U: where Uo is the rms value between any of the conductors and earth and U is the rms value of the voltage between any two conductors of the cable

00	Less than 100/100 V
01	Higher than 100/100 V and lower than 300/300 V
05	300 / V 500
07	450 / V 750
1	0,6 / 1 kV

Insulation and sheath material

B	Ethylene propylene rubber at a characteristic temperature of 60 ° C
N	Polychloroprene
N2	Polychloroprene for welding cables
Q	polyurethane
R	Rubber
V	Commonly used PVC
V2	PVC for operating temperatures of 90 ° C
V3	PVC for cables installed at low temperatures
V4	Cross-linked PVC
V5	Oil resistant PVC
Z	Compound based on polyolefins

Screens

C	Concentric copper conductor
C4	Copper braid screen on all cores
C5	Copper braid screen on the single cores
C7	Copper screen consisting of wires or strips or strips

 

Armature

Z2	Round steel wire armor
Z3	Steel plate armor
Z4	Steel strip armor
Z5	Steel wire braid

 

Construction form of the cable

H	Flat divisible cables, with or without sheath
H2	Non-divisible flat cables
H3	Flat cables with cores spaced from a strip
H6	Flat cable with 3 or more cores, according to HD 359
H7	Cable with double layer insulation applied by extrusion
H8	Extensible cord

 

Degree of flexibility of the conductor

D	Flexible conductor of cables for welding machines
E	Extremely flexible conductor for welding cables
F	Flexible conductor for cables for mobile installations (class 5 IEC 228)
H	Highly flexible conductor for cables for mobile installations (class 6 IEC 228)
K	Flexible cable conductor for fixed installations (class 5 IEC 228)
R	Rigid, round, stringed conductor
U	Rigid, round, single-wire conductor

 

Example of an identification:

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3) Main CEI standards

List of the main CEI standards relating to cables

CEI-UNEL 00722 table	HD 308	Distinctive colors of insulated cable cores
CEI-UNEL 35011 table	-	Cables for energy and signaling: designation abbreviations
CEI EN 50363 CEI 20-11	EN 50363	Technical characteristics and test requirements of compounds for insulation and sheaths of energy cables
IEC 20-13	IEC 60502	Rubber insulated cables with rated voltage from 1 to 30 kV
IEC 20-14	IEC 60502	PVC insulated cables for nominal voltages from 1 to 30 kV
IEC 20-19	HD 22	Rubber insulated cables with rated voltage not exceeding 450/750 V
IEC 20-20	HD 21	PVC insulated cables with rated voltage not exceeding 450/750 V
IEC 20-21	IEC 60287	Calculation of the current carrying capacity
CEI EN 50266 CEI 20-22	IEC 60332-3	Test of fire retardant cables
IEC 20-27	HD 361	Cable designation system for energy and signaling
CEI EN 60228 CEI 20-29	IEC 60228 / HD 383	Conductors for insulated cables
CEI EN 60811 CEI 20-34	EN 60811 / HD 505	Test methods
CEI EN 60332 / 1-2 - CEI 20-35 / 1-2	EN 60332-1-2 / IEC 60332-1-2	Tests on electrical cables in fire conditions
CEI EN 50200 CEI 20-36	IEC 60331	Fire resistance test of electric cables
CEI EN 50267 CEI 20-37	EN 50267-2-1 / IEC 60754-1	Tests on the gases emitted during the combustion of electric cables
IEC 20-38	-	Fire retardant rubber insulated cables with low emission of toxic and corrosive fumes and gases
IEC 20-40	HD 516	Guide to the use of low voltage cables
CEI EN 50414 CEI 20-85	EN 50414	Test methods for the analysis of the amount of lead in compounds for insulators, coatings and sheaths
-	BS 6004	PVC insulated cables for electrical power and lighting
-	VDE 0250	Isolierte starkstromleitungen
-	DIN 57250	Isolierte starkstromleitungen PVC mantelleitung mit Tragseil
-	DIN VDE 0293	Aderkennzeichnung von Starkstromkabeln und-isolierten Starkstromleitungen mit Nennspannung bis 1000 V

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4) Identification of the cores of the cables

Description

N.	Number of cables
1	Yellow green
2	Blue
3	Brown
4	Black
5	Grey

 

Cables with yellow-green protective conductor

Cables without yellow-green protective conductor

Flexible cables with yellow-green protective conductor

Flexible cables without yellow-green protective conductor

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5) Type of installation

Illustrations of some types of cable routing

• Electricity - Electronics
• Calculation of color coded electric resistances
• Electric - electronic tables
• Electrical drawing diagrams

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