IEC 60502-1:2021

IEC 60502-1 ®
Edition 3.0 2021-02
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Power cables with extruded insulation and their accessories for rated voltages
from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) –
Part 1: Cables for rated voltages of 1 kV (Um = 1,2 kV) and 3 kV (Um = 3,6 kV)

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IEC 60502-1 ®
Edition 3.0 2021-02
REDLINE VERSION
INTERNATIONAL
STANDARD
colour
inside
Power cables with extruded insulation and their accessories for rated voltages

from 1 kV (Um = 1,2 kV) up to 30 kV (Um = 36 kV) –

Part 1: Cables for rated voltages of 1 kV (Um = 1,2 kV) and 3 kV (Um = 3,6 kV)

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 29.060.20 ISBN 978-2-8322-9427-7

– 2 – IEC 60502-1:2021 RLV © IEC 2021
CONTENTS
FOREWORD . 4
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 9
4 Voltage designations and materials . 10
5 Conductors . 13
6 Insulation . 13
7 Assembly of multicore cables, inner coverings and fillers . 15
8 Metallic layers for single-core and multicore cables . 17
9 Metallic screen . 17
10 Concentric conductor . 18
11 Metallic sheath . 18
12 Metallic armour . 19
13 Oversheath . 22
14 Test conditions . 23
15 Routine tests . 24
16 Sample tests . 25
17 Type tests, electrical. 28
18 Type tests, non-electrical . 30
19 Electrical tests after installation . 37
Annex A (normative) Fictitious calculation method for determination of dimensions of
protective coverings . 52
Annex B (normative) Rounding of numbers . 58
Annex C (normative) Determination of hardness of HEPR insulation . 59
Bibliography . 61

Figure C.1 – Test on surfaces of large radius of curvature . 60
Figure C.2 – Test on surfaces of small radius of curvature . 60

Table 1 – Recommended rated AC voltages U . 11
Table 2 – Insulating compounds . 11
Table 3 – Maximum conductor temperatures for different types of insulating compound . 12
Table 4 – Sheathing compounds and maximum conductor temperatures for different
types of sheathing compound . 13
Table 5 – Nominal thickness of PVC/A insulation . 14
Table 6 – Nominal thickness of cross-linked polyethylene (XLPE) insulation . 14
Table 7 – Nominal thickness of ethylene propylene rubber (EPR) and hard ethylene
propylene rubber (HEPR) insulation . 15
Table 8 – Thickness of extruded inner covering . 16
Table 9 – Nominal diameter of round armour wires . 21
Table 10 – Nominal thickness of armour tapes . 21
Table 11 – Routine test voltages . 25

Table 12 – Number of samples for sample tests . 26
Table 13 – Electrical type test requirements for insulating compounds . 38
Table 14 – Non-electrical type tests (see Tables 15 to 23) . 39
Table 15 – Test requirements for mechanical characteristics of insulating compounds
(before and after ageing) . 40
Table 16 – Test requirements for particular characteristics of PVC insulating
compounds . 41
Table 17 – Test requirements for particular characteristics of various cross-linked
insulating compounds . 43
Table 18 – Test requirements for mechanical characteristics of sheathing compounds
(before and after ageing) . 45
Table 19 – Test requirements for particular characteristics of PVC sheathing
compounds . 46
Table 20 – Test requirements for particular characteristics of thermoplastic PE
sheathing compounds . 48
Table 21 – Test requirements for particular characteristics of halogen free sheathing
compounds . 48
Table 22 – Test requirements for particular characteristics of elastomeric sheathing
compounds . 50
Table 23 – Test methods and requirements for halogen free compounds . 51
Table A.1 – Fictitious diameter of conductor . 53
Table A.2 – Assembly coefficient k for laid-up cores . 54
Table A.3 – Increase of diameter for concentric conductors and metal screens . 55
Table A.4 – Increase of diameter for additional bedding . 57

– 4 – IEC 60502-1:2021 RLV © IEC 2021
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
POWER CABLES WITH EXTRUDED INSULATION
AND THEIR ACCESSORIES FOR RATED VOLTAGES
FROM 1 kV (U = 1,2 kV) UP TO 30 kV (U = 36 kV) –
m m
Part 1: Cables for rated voltages of 1 kV
(U = 1,2 kV) and 3 kV (U = 3,6 kV)
m m
FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international
co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and
in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports,
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2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international
consensus of opinion on the relevant subjects since each technical committee has representation from all
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5) IEC itself does not provide any attestation of conformity. Independent certification bodies provide conformity
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6) All users should ensure that they have the latest edition of this publication.
7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent
rights. IEC shall not be held responsible for identifying any or all such patent rights.
This redline version of the official IEC Standard allows the user to identify the changes made to
the previous edition IEC 60502-1:2004+AMD1:2009 CSV. A vertical bar appears in the margin
wherever a change has been made. Additions are in green text, deletions are in strikethrough
red text.
IEC 60502-1 has been prepared by IEC technical committee 20: Electric cables. It is an
International Standard.
This third edition cancels and replaces the second edition published in 2004 and
Amendment 1:2009. This edition constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) references to IEC 60811 (all parts) have been updated and mechanical testing requirements
specific to halogen free low-smoke oversheath of material type ST have been considered;
b) the use of the types of sheathing material to be used is now clearly defined;
c) the applicability of cables for use in DC systems is now included in the scope;
d) items which were earlier marked as "under consideration" were studied either for an
appropriate solution if found available, or for removal for the time being.
The text of this International Standard is based on the following documents:
Draft Report on voting
20/1938/FDIS 20/1949/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/standardsdev/publications.
A list of all parts in the IEC 60502 series, published under the general title Power cables with
extruded insulation and their accessories for rated voltages from 1 kV (U = 1,2 kV) up to 30 kV
m
(U = 36 kV) can be found on the IEC website.
m
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to
the specific document. At this date, the document will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it
contains colours which are considered to be useful for the correct understanding of its
contents. Users should therefore print this document using a colour printer.

– 6 – IEC 60502-1:2021 RLV © IEC 2021
POWER CABLES WITH EXTRUDED INSULATION
AND THEIR ACCESSORIES FOR RATED VOLTAGES
FROM 1 kV (U = 1,2 kV) UP TO 30 kV (U = 36 kV) –
m m
Part 1: Cables for rated voltages of 1 kV
(U = 1,2 kV) and 3 kV (U = 3,6 kV)
m m
1 Scope
This part of IEC 60502 specifies the construction, dimensions and test requirements of power
cables with extruded solid insulation for rated AC voltages of 1 kV (U = 1,2 kV) and 3 kV
m
(U = 3,6 kV) for fixed installations such as distribution networks or industrial installations.
m
Cables of rated AC voltage 1 kV (U = 1,2 kV) designed and tested in accordance with this
m
document can also be used, if declared by the manufacturer, in DC distribution systems having
their nominal voltage ≤ 750 V DC (with a maximum of 900 V DC) between a live conductor and
neutral/earth, or ≤ 1 500 V DC (with a maximum 1 800 V DC) between two live conductors.
Applicable core identification for DC systems are considered in accordance with local
installation regulations.
NOTE 1 Recommendations for preferred core colours for line conductors in DC systems are given in IEC 60445.
However, local installation regulations for DC systems can already contain specific identification requirements.
This document includes cables which exhibit properties of reduced flame spread, low levels of
smoke emission and halogen-free gas emission when exposed to fire.
Cables for special installation and service conditions are not included, for example cables for
overhead networks, the mining industry, nuclear power plants (in and around the containment
area), submarine use or shipboard application, or cables directly connected to photovoltaic
systems.
NOTE 2 Cables for photovoltaic systems are covered by IEC 62930.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60038:1983, IEC standard voltages
IEC 60060-1:1989, High-voltage test techniques – Part 1: General definitions and test
requirements
IEC 60183:1984, Guidance for the selection of high-voltage A.C. cable systems
IEC 60228:1978, Conductors of insulated cables
IEC 60230:1966, Impulse tests on cables and their accessories

IEC 60332-1:1993, Tests on electric cables under fire conditions – Part 1: Test on a single
vertical insulated wire or cable
IEC 60332-1-2, Tests on electric and optical fibre cables under fire conditions – Part 1-2: Test
for vertical flame propagation for a single insulated wire or cable – Procedure for 1 kW
pre‑mixed flame
IEC 60332-3-24:2000, Tests on electric and optical cables under fire conditions – Part 3-24:
Test for vertical flame spread of vertically-mounted bunched wires or cables – Category C
IEC 60502-2:1997, Power cables with extruded insulation and their accessories for rated
voltages from 1 kV (U = 1,2 kV) up to 30 kV (U = 36 kV) – Part 2: Cables for rated voltages
m m
from 6 kV (U = 7,2 kV) up to 30 kV (U = 36 kV)
m m
IEC 60684-2:1987, Flexible insulating sleeving – Part 2: Methods of test
IEC 60724:2000, Short-circuit temperature limits of electric cables with rated voltages of 1 kV
(U = 1,2 kV) and 3 kV (U = 3,6 kV)
m m
IEC 60754-1:1994, Test on gases evolved during combustion of materials from cables – Part 1:
Determination of the amount of halogen acid gas content
IEC 60754-2:1991, Test on gases evolved during combustion of electric materials from cables
– Part 2: Determination of degree of acidity of gases evolved during the combustion of materials
taken from electric cables by measuring pH (by pH measurement) and conductivity
IEC 60811-1-1:1993, Common test methods for insulating and sheathing materials of electric
cables – Part 1: Methods for general application – Section 1: Measurement of thickness and
overall dimensions – Tests for determining the mechanical properties
IEC 60811-1-2:1985, Common test methods for insulating and sheathing materials of electric
cables – Part 1: Methods for general application – Section 2: Thermal ageing methods
IEC 60811-1-3:1993, Common test methods for insulating and sheathing materials of electric
cables – Part 1: Methods for general application – Section 3: Methods for determining the
density – Water absorption tests – Shrinkage test
IEC 60811-1-4:1985, Common test methods for insulating and sheathing materials of electric
cables – Part 1: Methods for general application – Section 4: Tests at low temperature
IEC 60811-2-1:1998, Insulating and sheathing materials of electric and optical cables –
Common test methods – Part 2-1: Methods specific to elastomeric compounds – Ozone
resistance, hot set and mineral oil immersion tests
IEC 60811-3-1:1985, Common test methods for insulating and sheathing materials of electric
cables – Part 3: Methods specific to PVC compounds – Section 1: Pressure test at high
temperature – Tests for resistance to cracking
IEC 60811-3-2:1985, Common test methods for insulating and sheathing materials of electric
cables – Part 3: Methods specific to PVC compounds – Section 2: Loss of mass test – Thermal
stability test
IEC 60811-4-1:1985, Common test methods for insulating and sheathing materials of electric
cables – Part 4: Methods specific to polyethylene and polypropylene compounds – Section 1:
Resistance to environmental stress cracking – Wrapping test after thermal ageing in air –
Measurement of the melt flow index – Carbon black and/or mineral content measurement in PE

– 8 – IEC 60502-1:2021 RLV © IEC 2021
IEC 61034-2: 1997, Measurement of smoke density of cables burning under defined conditions –
Part 2: Test procedure and requirements
ISO 48:1994, Rubber, vulcanized or thermoplastic – Determination of hardness (hardness
between 10 IRHD and 100 IRHD)
IEC 60811-201, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 201: General tests – Measurement of insulation thickness
IEC 60811-202, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 202: General tests – Measurement of thickness of non-metallic sheath
IEC 60811-203, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 203: General tests – Measurement of overall dimensions
IEC 60811-401, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 401: Miscellaneous tests – Thermal ageing methods – Ageing in an air oven
IEC 60811-402, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 402: Miscellaneous tests – Water absorption tests
IEC 60811-403, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 403: Miscellaneous tests – Ozone resistance test on cross-linked compounds
IEC 60811-404, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 404: Miscellaneous tests – Mineral oil immersion tests for sheaths
IEC 60811-409, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 409: Miscellaneous tests – Loss of mass test for thermoplastic insulations and sheaths
IEC 60811-501, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 501: Mechanical tests – Tests for determining the mechanical properties of insulating and
sheathing compounds
IEC 60811-502, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 502: Mechanical tests – Shrinkage test for insulations
IEC 60811-503, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 503: Mechanical tests – Shrinkage test for sheaths
IEC 60811-504, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 504: Mechanical tests – Bending tests at low temperature for insulations and sheaths
IEC 60811-505, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 505: Mechanical tests – Elongation at low temperature for insulations and sheaths
IEC 60811-506, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 506: Mechanical tests – Impact test at low temperature for insulations and sheaths
IEC 60811-507, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 507: Mechanical tests – Hot set test for cross-linked materials
IEC 60811-508, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 508: Mechanical tests – Pressure test at high temperature for insulation and sheaths

IEC 60811-509, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 509: Mechanical tests – Test for resistance of insulations and sheaths to cracking (heat
shock test)
IEC 60811-605, Electric and optical fibre cables – Test methods for non-metallic materials –
Part 605: Physical tests – Measurement of carbon black and/or mineral filler in polyethylene
compounds
IEC 60811-606, Electric and optical fibre cables –Test methods for non-metallic materials –
Part 606: Physical tests – Methods for determining the density
IEC 61034-2, Measurement of smoke density of cables burning under defined conditions –
Part 2: Test procedure and requirements
IEC 62230, Electric cables – Spark-test method
ISO 48-2:2018, Rubber, vulcanized or thermoplastic – Determination of hardness – Part 2:
Hardness between 10 IRHD and 100 IRHD
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following
addresses:
• IEC Electropedia: available at http://www.electropedia.org/
• ISO Online browsing platform: available at http://www.iso.org/obp
3.1 Definitions of dimensional values (thicknesses, cross-sections, etc.)
3.1.1
nominal value
value by which a quantity is designated and which is often used in tables
Note 1 to entry: Usually, in this document, nominal values give rise to values to be checked by measurements
taking into account specified tolerances.
3.1.2
approximate value
value which is neither guaranteed nor checked but is used, for example, for the calculation of
other dimensional values
3.1.3
median value
when several test results have been obtained and ordered in an increasing (or decreasing)
succession, middle value if the number of available values is odd, and mean of the two middle
values if the number is even
3.1.4
fictitious value
value calculated in accordance with the "fictitious method'' described in Annex A

– 10 – IEC 60502-1:2021 RLV © IEC 2021
3.2 Definitions relating to tests
3.2.1
routine test
test made by the manufacturer on each manufactured length of cable to check that each length
meets the specified requirements
3.2.2
sample test
test made by the manufacturer on samples of completed cable or components taken from a
completed cable, at a specified frequency, so as to verify that the finished product meets the
specified requirements
3.2.3
type test
test made before supplying, on a general commercial basis, a type of cable covered by this
document, in order to demonstrate satisfactory performance characteristics to meet the
intended application
Note 1 to entry: These Type tests are of such a nature that, after they have been made, they need not be repeated,
unless changes are made in the cable materials or design or manufacturing process which might change the
performance characteristics.
3.2.4
electrical test after installation
test made to demonstrate the integrity of the cable and its accessories as installed
4 Voltage designations and materials
4.1 Rated voltages
4.1.1 Rated AC voltages
The rated AC voltages U /U (U ) of the cables considered in this document are 0,6/1 (1,2) kV
0 m
and 1,8/3 (3,6) kV.
NOTE 1 The voltages given above are the correct designations although in some countries other designations are
used, e.g. 1,7/3 kV or 1,9/3,3 kV instead of 1,8/3 kV.
For the voltage designation of cables U /U (U ), the definitions in IEC 60183 apply i.e.:
0 m
U is the rated RMS power frequency voltage between conductor and earth or metallic screen
for which the cable is designed;
U is the rated RMS power frequency voltage between conductors for which the cable is
designed;
U is the maximum value of the "highest system voltage'' for which the equipment may be
m
used (see IEC 60038) RMS power frequency voltage between conductors for which the
cable is designed.
NOTE 2 U is the highest voltage that can be sustained under normal operating conditions at any time and at any
m
point in a system and excludes temporary voltage variations due to fault conditions and sudden disconnection of
large loads.
The rated voltage of the cable for a given application shall be suitable for the operating
conditions in the system in which the cable is used. To facilitate the selection of the cable,
systems are divided into three categories according to the duration of time the system can be
operated under earth fault conditions (see IEC 60183):

– Category A: this category comprises those systems in which any phase conductor that
comes in contact with earth or an earth conductor is disconnected from the
system within 1 min.
– Category B: this category comprises those systems which, under fault conditions, are
operated for a short time with one phase earthed. This period, in
accordance with IEC 60183, should, in general, not exceed 1 h. For cables
covered by this document, a longer period, not exceeding 8 h on any
occasion, can be tolerated. The total duration of earth faults in any year
should not exceed 125 h.
– Category C: this category comprises all systems which do not fall into category A or B.

NOTE 3 It should be realized that In a system where an earth fault is not automatically and promptly isolated, the
extra stresses on the insulation of cables during the earth fault reduce the life of the cables to a certain degree. If
the system is expected to be operated fairly often with a permanent earth fault, it may can be advisable to classify
the system in Category C.
The values of U recommended for cables to be used in three-phase systems are listed in
Table 1.
Table 1 – Recommended rated AC voltages U
Highest system voltage Rated voltage (U )
(U )
m
kV kV
Categories A and B Category C
1,2 0,6 0,6
a
3,6 1,8
3,6
a
This category is covered by 3,6/6 (7,2) kV cables in accordance with
IEC 60502‑2.
4.1.2 Rated DC voltages
Under consideration.
4.2 Insulating compounds
The types of insulating compound covered by this document are listed in Table 2, together with
their abbreviated designations.
Table 2 – Insulating compounds
Abbreviated
Insulating compound
designation
a) Thermoplastic
a
Polyvinyl chloride intended for cables with rated voltages U /U ≤ 1,8/3 kV
PVC/A
b) Cross-linked:
Ethylene propylene rubber or similar (EPM or EPDM) EPR
High modulus or hard grade ethylene propylene rubber HEPR
Cross-linked polyethylene XLPE
a
Insulating compound based on polyvinyl chloride intended for cables with rated AC voltages U /U = 3,6/6 kV
is designated PVC/B in IEC 60502-2.

– 12 – IEC 60502-1:2021 RLV © IEC 2021
The maximum conductor temperatures for different types of insulating compound covered by
this document are given in Table 3.
Table 3 – Maximum conductor temperatures for different types of insulating compound
Maximum conductor temperature
°C
Insulating compound
Short-circuit
Normal operation (5 s maximum
duration)
Polyvinyl chloride (PVC/A)
70 160
Conductor cross-section ≤ 300 mm
70 140
Conductor cross-section > 300 mm
Cross-linked polyethylene (XLPE) 90 250
Ethylene propylene rubber (EPR and HEPR) 90 250

The temperatures in Table 3 are based on the intrinsic properties of the insulating materials. It
is important to take into account other factors when using these values for the calculation of
current ratings.
For example, in normal operation, if a cable directly buried in the ground is operated under
continuous load (100 % load factor) at the maximum conductor temperature shown in Table 3,
the thermal resistivity of the soil surrounding the cable may, in the course of time, increase from
its original value as a result of drying-out processes. As a consequence, the conductor
temperature may greatly exceed the maximum value. If such operating conditions are foreseen,
adequate provisions shall be made.
For guidance on the short-circuit temperatures, reference should shall be made to IEC 60724.
4.3 Sheathing compounds
The types of sheathing compound covered by this document are listed in Table 4, together with
their abbreviated designations.
The maximum conductor temperatures for the different types of sheathing compound covered
by this document are given in Table 4.

Table 4 – Sheathing compounds and maximum conductor temperatures
for different types of sheathing compound
Maximum conductor
Abbreviated
temperature
designation
Sheathing compound
in normal operation
°C
a) Thermoplastic:
Polyvinyl chloride (PVC) ST 80
ST 90
Polyethylene ST 80
ST 90
Halogen free ST 90
b) Elastomeric:
Polychloroprene, chlorosulfonated polyethylene or SE 85
similar polymers
5 Conductors
The conductors shall be either of Class 1 or Class 2 of plain or metal-coated annealed copper
or of plain aluminium or aluminium alloy, or of Class 5 of plain or metal-coated copper in
accordance with IEC 60228.
6 Insulation
6.1 Material
The insulation shall be extruded dielectric of one of the types listed in Table 2.
For halogen free cables, the insulation shall also meet the requirements given in Table 23.
6.2 Insulation thickness
The nominal insulation thicknesses are specified in Table 5 to Table 7.
The thickness of any separator shall not be included in the thickness of the insulation.

– 14 – IEC 60502-1:2021 RLV © IEC 2021
Table 5 – Nominal thickness of PVC/A insulation
Nominal cross-sectional area of Nominal thickness of insulation at rated voltage
conductor
U / U (U )
0 m
0,6/1 (1,2) kV 1,8/3 (3,6) kV
mm mm
mm
1,5 and 2,5 0,8 –
4 and 6 1,0 –
10 and 16 1,0 2,2
25 and 35 1,2 2,2
50 and 70 1,4 2,2
95 and 120 1,6 2,2
150 1,8 2,2
185 2,0 2,2
240 2,2 2,2
300 2,4 2,4
400 2,6 2,6
500 to 800 2,8 2,8
1 000 3,0 3,0
NOTE Any conductor cross-section smaller than those given in this table is not recommended.

Table 6 – Nominal thickness of cross-linked polyethylene (XLPE) insulation
Nominal cross-sectional area of Nominal thickness of insulation at rated voltage
conductor
U / U (U )
0 m
0,6/1 (1,2) kV 1,8/3 (3,6) kV
mm mm
mm
1,5 and 2,5 0,7 –
4 and 6 0,7 –
10 and 16 0,7 2,0
25 and 35 0,9 2,0
50 1,0 2,0
70 and 95 1,1 2,0
120 1,2 2,0
150 1,4 2,0
185 1,6 2,0
240 1,7 2,0
300 1,8 2,0
400 2,0 2,0
500 2,2 2,2
630 2,4 2,4
800 2,6 2,6
1 000 2,8 2,8
NOTE Any conductor cross-section smaller than those given in this table is not recommended.

Table 7 – Nominal thickness of ethylene propylene rubber (EPR)
and hard ethylene propylene rubber (HEPR) insulation
Nominal cross-sectional Nominal thickness of insulation at rated voltage
area of conductor
U / U (U )
0 m
0,6/1 (1,2) kV 1,8/3 (3,6) kV
EPR HEPR EPR HEPR
mm mm mm mm
mm
1,5 and 2,5 1,0 0,7 – –
4 and 6 1,0 0,7 – –
10 and 16 1,0 0,7 2,2 2,0
25 and 35 1,2 0,9 2,2 2,0
50 1,4 1,0 2,2 2,0
70 1,4 1,1 2,2 2,0
95 1,6 1,1 2,4 2,0
120 1,6 1,2 2,4 2,0
150 1,8 1,4 2,4 2,0
185 2,0 1,6 2,4 2,0
240 2,2 1,7 2,4 2,0
300 2,4 1,8 2,4 2,0
400 2,6 2,0 2,6 2,0
500 2,8 2,2 2,8 2,2
630 2,8 2,4 2,8 2,4
800 2,8 2,6 2,8 2,6
1 000 3,0 2,8 3,0 2,8
NOTE Any conductor cross-section smaller than those given in this table is not recommended.

7 Assembly of multicore cables, inner coverings and fillers
7.1 General
The assembly of multicore cables depends on the rated voltage and whether a metallic layer is
applied to each core.
The following Subclauses 7.2 to 7.4 do not apply to assemblies of sheathed single-core cables.
7.2 Inner coverings and fillers
7.2.1 Construction
The inner coverings may be extruded or lapped.
For cables with circular cores, except cables with more than five cores, a lapped inner covering
shall be permitted only if the interstices between the cores are substantially filled.
A suitable binder is permitted before application of an extruded inner covering.

– 16 – IEC 60502-1:2021 RLV © IEC 2021
7.2.2 Material
The materials used for inner coverings and fillers shall be suitable for the operating temperature
of the cable and compatible with the insulating material.
For halogen free cables, the inner covering and fillers shall meet the requirements given in
Table 23.
7.2.3 Thickness of extruded inner covering
The approximate thickness of extruded inner coverings shall be derived from Table 8.
Table 8 – Thickness of extruded inner covering
Fictitious diameter over laid-up cores Thickness of extruded inner covering
(approximate values)
Above Up to and including
mm mm mm
– 25 1,0
25 35 1,2
35 45 1,4
45 60 1,6
60 80 1,8
80 – 2,0
7.2.4 Thickness of lapped inner coverings
The approximate thickness of lapped inner coverings shall be 0,4 mm for fictitious diameters
over laid-up cores up to and including 40 mm and 0,6 mm for larger diameters.
7.3 Cables with rated voltage 0,6/1 (1,2) kV
7.3.1 General
Cables with a rated voltage of 0,6/1 (1,2) kV may have a metallic layer collectively surrounding
the cores.
NOTE The choice between cables having and cables not having a metallic layer depends upon national regulations
and installation requirements for the prevention of possible dangers from mechanical damage or direct electrical
contact.
7.3.2 Cables having a collective metallic layer (see Clause 8)
Cables shall have an inner covering over the laid-up cores. The inner covering and fillers shall
comply with 7.2.
Metallic tapes may, however, be applied directly over the assembled cores, omitting the inner
covering, provided that the nominal thickness of each tape does not exceed 0,3 mm and that
the completed cable complies with the special bending test specified in 18.18.
7.3.3 Cables having no collective metallic layer (see Clause 8)
The inner covering may be omitted, provided the outer shape of the cable remains practically
circular and no adhesion occurs between cores and sheath.

The oversheath may penetrate into the interstices of the cores, except in the case of
thermoplastic oversheaths over circular cores exceeding 10 mm .
If, however, an inner covering is applied, its thickness need not comply with 7.2.3 or 7.2.4.
7.4 Cables with rated voltage 1,8/3 (3,6) kV
7.4.1 General
Cables with a rated voltage of 1,8/3 (3,6) kV shall have a metallic layer surrounding the cores
either individually or collectively.
7.4.2 Cables having only a collective metallic layer (see Clause 8)
Cables shall have an inner covering over the laid-up cores. The inner covering and fillers shall
comply with 7.2 and shall be non-hygroscopic.
7.4.3 Cables having a metallic layer over each individual core (see Clause 9)
The metallic layers of the individual cores shall be in contact with each other.
Cables with an additional collective metallic layer (see Clause 8) of the same material as the
underlying individual metallic layers shall have an inner covering over the laid-up cores. The
inner covering and fillers shall comply with 7.2 and shall be non-hygroscopic.
When the underlying individual metallic layers and the collective metallic layer are of different
materials, they shall be separated by an extruded sheath of one of the materials specified
in 13.2. For lead-sheathed cables, the separation from the underlying individual metallic layers
may be obtained by an inner covering in accordance with 7.2.
For cables having neither armour, nor concentric conductor, nor other collective metallic layer
(see Clause 8), the inner covering may be omitted, provided the outer shape of the cable
remains practically circular. The oversheath may penetrate into the interstices of the cores,
except in the case of thermoplastic oversheaths over circular cores exceeding 10 mm . If,
however, an inner covering is applied, its thickness need not comply with 7.2.3 nor 7.2.4.
8 Metallic layers for single-core and multicore cables
The following types of metallic layers are included in this document:
a) metallic screen (see Clause 9);
b) concentric conductor (see Clause 10);
c) lead sheath (see Clause 11);
d) metallic armour (see Clause 12).
The metallic layer(s) shall comprise one or more of the types listed above and shall be non-
magnetic when applied to either single-core cables or individual cores of multicore cables.
9 Metallic screen
9.1 Construction
The metallic screen shall consist of one or more tapes, or a braid, or a concentric layer of wires
or a combination of wires and tape(s).

– 18 – IEC 60502-1:2021 RLV © IEC 2021
It may also be a sheath or, in the case of a collective screen, an armour which complies with 9.2.
When choosing the material of the screen, special consideration shall be given to the possibility
of corrosion, not only for mechanical safety but also for electrical safety.
Gaps in the screen shall comply with national regulations and/or standards.
9.2 Requirements
The dimensional, physical and electrical requirements of the metallic screen shall be
determined by national regulations and/or standards.
10 Concentric conductor
10.1 Construction
Gaps in the concentric conductor shall comply with national regulations and/or standards.
When choosing the material of the concentric conductor, special consideration shall be given
to the possibility of corrosion, not only for mechanical safety but also for electrical safety.
10.2 Requirements
The dimensional and physical requirements of the concentric conductor and its electrical
resistance shall be determined by national regulations and/or standards.
10.3 Application
When a concentric conductor i
...