IEC 60519-1:2003

INTERNATIONAL IEC
STANDARD
60519-1
Third edition
2003-07
Safety in electroheat installations–
Part 1:
General requirements
Sécurité dans les installations électrothermiques –
Partie 1:
Exigences générales
Reference number
Publication numbering
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60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1.

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edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the

base publication incorporating amendment 1 and the base publication incorporating

amendments 1 and 2.
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INTERNATIONAL IEC
STANDARD
60519-1
Third edition
2003-07
Safety in electroheat installations–
Part 1:
General requirements
Sécurité dans les installations électrothermiques –
Partie 1:
Exigences générales
 IEC 2003  Copyright - all rights reserved
No part of this publication may be reproduced or utilized in any form or by any means, electronic or
mechanical, including photocopying and microfilm, without permission in writing from the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch  Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale
U
International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – 60519-1  IEC:2003(E)
CONTENTS
FOREWORD . 4

1 General. 6

1.1 Scope . 6

1.2 Object. 7

2 Normative references. 7

3 Terms and definitions. 8

3.1 General terms. 8
3.2 Electrical quantities and terms .10
4 Classification of electroheat equipment according to voltage bands .13
4.1 Voltage classification .13
4.2 Voltage bands.13
5 Classification of electroheat equipment according to frequency bands .13
5.1 Direct current equipment.13
5.2 Low-frequency equipment .13
5.3 Mains-frequency equipment .13
5.4 Medium-frequency equipment .13
5.5 High-frequency equipment .14
5.6 Microwave equipment .14
6 General requirements.14
6.1 Electroheat equipment .14
6.2 Electrical equipment of electroheat installations.15
6.3 Static charges – Stray fields – Electric and/or magnetic fields.16
6.4 Impact of electromagnetic effects.16
6.5 Ionizing radiation.16
6.6 Liquid cooling.17
7 Isolation and switching .17
7.1 Switching-off of special circuits .17
7.2 Switching at high voltage levels.18
8 Connection to the supply network and internal connections.18
8.1 General requirements .18
8.2 Fixed connection.18

8.3 Removable connection and flexible conductors.18
9 Protection against electric shock .19
9.1 General .19
9.2 Direct contact – special measures.19
9.3 Indirect contact – special measures .20
9.4 Recommendations for the operating instructions .20
10 Protection against overcurrent.20
11 Equipotential bonding.20
11.1 General .20
11.2 Protective bonding circuits .20
11.3 Bonding for operational purposes .21
11.4 Prohibition of the use of earth as part of an active circuit .21

60519-1  IEC:2003(E) – 3 –
12 Control circuits and control functions .21

12.1 Control circuits.21

12.2 Earthing of control circuits.22

13 Protection against thermal influences .23

14 Risk of fire and danger of explosion .23

15 Marking, labelling and technical documentation .23

15.1 Marking .23

15.2 Labelling.24

15.3 Technical documentation .24

16 Information on inspection and commissioning, and instructions for utilization and
maintenance of electroheat installations .24
16.1 General requirements .24
16.2 Information on inspection and commissioning.25
16.3 Instructions for utilization to be given in the technical documentation .25
16.4 Instructions for maintenance work to be given in the technical documentation.25
Bibliography .27

– 4 – 60519-1  IEC:2003(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION

____________
SAFETY IN ELECTROHEAT INSTALLATIONS –

Part 1: General requirements
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, and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to
technical committees; any IEC National Committee interested in the subject dealt with may participate in this
preparatory work. International, governmental and non-governmental organizations liaising with the IEC also
participate in this preparation. IEC collaborates closely with the International Organization for Standardization
(ISO) in accordance with conditions determined by agreement between the two organizations.
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
interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National
Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC
Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any
misinterpretation by any end user.
4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications
transparently to the maximum extent possible in their national and regional publications. Any divergence
between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in
the latter.
5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
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
members of its technical committees and IEC National Committees for any personal injury, property damage or
other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and
expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC
Publications.
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.
International Standard IEC 60519-1 has been prepared by IEC technical committee 27:
Industrial electroheating equipment.

This third edition cancels and replaces the second edition published in 1984. It constitutes
a technical revision.
In this third edition of IEC 60519-1 significant technical changes with respect to the previous
edition are as follows:
– the scope is now extended to cover also voltage band 3 equipment with rated voltage not
exceeding 3 600 V a.c. or 5 000 V d.c.; the relevant provisions for such equipment have
been added in clauses on, for example protection against electric shock, equipotential
bonding or maintenance work;
– requirements concerning equipotential bonding have been essentially modified and
introduced in a separate clause, based on the actual relevant provisions of IEC 60204-1;
– general provisions on the impact of electromagnetic effects have been given;
– information concerning technical documentation has been modified;
– a bibliography has been added.

60519-1  IEC:2003(E) – 5 –
The text of this standard is based on the following documents:

FDIS Report on voting
27/358/FDIS 27/377/RVD
Full information on the voting for the approval of this standard can be found in the report on

voting indicated in the above table.

This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

The committee has decided that the contents of this publication will remain unchanged until
2008. At this date, the publication will be
• reconfirmed;
• withdrawn;
• replaced by a revised edition, or
• amended.
IEC 60519 consists of the following parts, under the general title Safety in electroheat
installations:
Part 1: General requirements
Part 2: Particular requirements for resistance heating equipment
Part 3: Particular requirements for induction and conduction heating and induction melting
installations
Part 4: Particular requirements for arc furnace installations
Part 5: Specifications for safety in plasma installations
Part 6: Specifications for safety in industrial microwave heating equipment
Part 7: Particular requirements for installations with electron guns
Part 8: Particular requirements for electroslag remelting furnaces
Part 9: Particular requirements for high-frequency dielectric heating installations
Part 10: Particular requirements for electrical resistance trace heating systems for industrial
and commercial applications
Part 11: Particular requirements for installations for electromagnetic stirring, transport or
pouring of metal liquids
Part 21: Particular requirements for resistance heating equipment – Heating and melting
glass equipment
NOTE If necessary, additional parts covering particular industrial electroheat equipment may be considered.
General test methods for industrial electroheating installations are specified in IEC 60398.
Additional information on non-electrical hazards possibly arising from the utilization of industrial
electroheat equipment may be taken from European Standard EN 746-1 (see Bibliography),
which specifies common safety requirements for industrial thermoprocessing equipment, as
well as of an electrical and of a non-electrical kind.
A bilingual version of this standard may be issued at a later date.
———————
Under consideration.
– 6 – 60519-1  IEC:2003(E)
SAFETY IN ELECTROHEAT INSTALLATIONS –

Part 1: General requirements
1 General
1.1 Scope
This part of IEC 60519 is applicable to industrial electroheat installations, which may comprise
electroheat equipment in the voltage range up to 3 600 V a.c. or 5 000 V d.c., and deals with
the general safety requirements.
Where requirements given in this standard differ from those given in other IEC publications, an
equivalent degree of safety shall be ensured.
The present requirements apply to industrial electroheat and associated treatment installations
such as:
– direct arc furnaces;
– submerged arc furnaces;
– equipment for arc heating (other than arc furnaces);
– electroslag remelting furnaces;
– plasma equipment;
– induction melting furnaces;
– equipment for induction heating;
– equipment for direct resistance heating;
– equipment for indirect resistance heating;
– equipment for infra-red radiation heating;
– equipment for dielectric heating;
– equipment with electron guns;
– microwave heating equipment;
– industrial laser equipment;
– electroheat surface treatment equipment.

NOTE The list is intended to present some typical examples of installations covered by this standard. It is not
exhaustive.
This standard is not applicable to electric cooking and heating equipment for household or
welding purposes, nor does it apply to space heating of any kind.
This standard refers to the normal operation of industrial electroheat installations; it is also
intended to ensure the safety of persons in the case of abnormal operation and when faults
occur in electroheat installations. Inspection, commissioning, utilization and maintenance are
dealt with in Clause 16.
This standard assumes that the installations are operated and maintained by skilled or
instructed persons according to 3.1.8 and 3.1.9.

60519-1  IEC:2003(E) – 7 –
1.2 Object
The requirements for the safety of persons in electroheat installations are the subject, on the

one hand, of general requirements applicable to electroheat installations as a whole and, on

the other hand, of particular requirements applicable to each of them. This standard gives only

general requirements.
These safety requirements concern the protection of persons against dangers of particularly

electrical origin and also against certain dangers of non-electrical origin.

The safety requirements to be observed result from the joint application of general

requirements and particular requirements concerning the specific industrial application of the
electroheat. Where particular requirements exist they shall complete, modify or replace the
general requirements. In the absence of particular requirements, the requirements to be
complied with are those, which are specified in this standard.
In addition, for electroheat installations of voltage bands 1 and 2 and frequencies of up to
60 Hz, the following parts of IEC 60364 shall apply: IEC 60364-1, IEC 60364-4-41, IEC 60364-
4-42, IEC 60364-4-43, IEC 60364-5-53, IEC 60364-5-54.
For voltage band 3, electroheat equipment with rated voltage not exceeding 3 600 V a.c. or
5 000 V d.c., special requirements shall be complied with. Such requirements are specified in
this standard. For rated voltage exceeding 3 600 V a.c. or 5 000 V d.c., additional
specifications are under consideration.
In addition, for electrical equipment of up to 1 000 V a.c. or 1 500 V d.c. and frequencies of up
to 200 Hz, IEC 60204-1 may be taken as a guidance. IEC 60204-1 however does not cover
power circuits.
2 Normative references
The following referenced documents are indispensable for the application 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 60050-195:1998, International Electrotechnical Vocabulary (IEV) – Part 195: Earthing and
protection against electric shock
Amendment 1(2001)
IEC 60050-521:2002, International Electrotechnical Vocabulary (IEV) – Part 521: Semiconductor
devices and integrated circuits

IEC 60050-826:1982, International Electrotechnical Vocabulary (IEV) – Part 826: Electrical
installations of buildings
Amendment 1(1990), Amendment 2(1995) and Amendment 3(1999)
IEC 60050-841:1983, International Electrotechnical Vocabulary (IEV) – Part 841: Industrial
electroheating
IEC 60071-1, Insulation co-ordination – Part 1: Definitions, principles and rules
IEC 60110-1:1998, Power capacitors for induction heating installations – Part 1: General
IEC 60204-1:1997, Safety of machinery – Electrical equipment of machines – Part 1: General
requirements
———————
There is a consolidated edition 4.1 (2000) that includes IEC 60204-1 (1997) and its amendment 1 (1999).

– 8 – 60519-1  IEC:2003(E)
IEC 60364-1, Electrical installations of buildings – Part 1: Fundamental principles, assessment

of general characteristics, definitions

IEC 60364-4-41, Electrical installations of buildings – Part 4-41: Protection for safety –

Protection against electric shock

IEC 60364-4-42, Electrical installations of buildings – Part 4-42: Protection for safety –
Protection against thermal effects

IEC 60364-4-43, Electrical installations of buildings – Part 4-43: Protection for safety –

Protection against overcurrent

IEC 60364-5-53, Electrical installations of buildings – Part 5-53: Selection and erection of
electrical equipment – Isolation, switching and control
IEC 60364-5-54, Electrical installations of buildings – Part 5-54: Selection and erection of
electrical equipment – Earthing arrangements, protective conductors and protective bonding
conductors
IEC 60417-DB , Graphical symbols for use on equipment
IEC 60446, Basic and safety principles for man-machine interface, marking and identification –
Identification of conductors by colours or numerals
IEC 60529, Degrees of protection provided by enclosures (IP Code)
IEC 60664-1, Insulation coordination for equipment within low-voltage systems – Part 1:
Principles, requirements and tests
CISPR 11, Industrial, scientific and medical (ISM) radio-frequency equipment – Electro-
magnetic disturbance characteristics – Limits and methods of measurement
ISO 7000, Graphical symbols for use on equipment – Index and synopsis
3 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60050-841 and the
following apply.
3.1 General terms
3.1.1
electrical equipment
item used for such purposes as generation, conversion, transmission, distribution or utilization
of electrical energy, such as converters, transformers, capacitors, switchgear and controlgear,
measuring instruments, protective devices, wiring systems and appliances
[IEV 826-07-01, modified]
3.1.2
electrical installation
assembly of associated electrical equipment having co-ordinated characteristics to fulfil
specific purposes
[IEV 826-01-01, modified]
———————
DB refers to the IEC on-line database.
There is a consolidated edition 1.2 (2002) that includes IEC 60664-1 (1992) and its amendment 1 (2000) and
amendment 2 (2002).
60519-1  IEC:2003(E) – 9 –
3.1.3
electroheat equipment
electrical equipment used for the conversion of electric energy into heat for useful purposes

[IEV 841-01-05, modified]
3.1.4
electroheat installation
electroheat equipment with the electrical and mechanical accessories needed for its operation

and use
[IEV 841-01-06, modified]
3.1.5
enclosure
housing affording the type and degree of protection suitable for the intended application
[IEV 195-02-35]
NOTE For the classification of degrees of protection provided by enclosures (IP Code), see IEC 60529.
3.1.6
hazard
source of possible injury or damage to health
[ISO/TR 12100-1, 3.5, modified]
3.1.7
fault
the state of an item characterized by inability to perform a required function, excluding the
inability during preventive maintenance or other planned actions, or due to lack of external
resources
NOTE 1 A fault is often the result of a failure of the item itself, but may exist without prior failure.
NOTE 2 In English, the term “fault” and its definition are identical with those given in IEV 191-05-01. In the field of
machinery, the French term “défaut” and the German term “Fehler” are used rather than the terms “panne” and
“Fehlzustand” that appear with this definition.
[IEC 60204-1, 3.24]
3.1.8
(electrically) skilled person
person with relevant education and experience to enable him or her to perceive risks and to
avoid hazards which electroheat installations can create

[IEV 826-09-01, modified]
3.1.9
(electrically) instructed person
person adequately advised or supervised by electrically skilled persons to enable him or her to
perceive risks and to avoid hazards which electroheat installations can create (operating and
maintenance staff)
[IEV 826-09-02, modified]
– 10 – 60519-1  IEC:2003(E)
3.2 Electrical quantities and terms

Unless otherwise stated, the terms "voltage" and "current" apply to the r.m.s. values in the

case of a.c.
The electrical terms and quantities associated with the word "rated" refer to the electroheat

equipment itself, unless otherwise stated.

The terms "rated voltage", "rated current" or "rated power" apply to the voltage (in the case of a

three-phase system, the voltage between phases), the current or the power specified by the

manufacturer and indicated on the electroheat equipment.

3.2.1
rated voltage
voltage for which an installation (or part of an installation) is designed
3.2.2
rated voltage range
interval between the highest and lowest voltage specified and indicated on the equipment by
the manufacturer
3.2.3
supply network
supply system
electric power transmission and distribution system that is not used exclusively for supplying
the electroheat installation
3.2.4
live part
conductor or conductive part intended to be energized in normal use, including a neutral
conductor, but, by convention, not a PEN conductor
[IEV 826-03-01]
NOTE For PEN conductor, see 3.2.12.
3.2.5
insulation
all the insulating materials necessary to ensure the proper operation of the equipment and
protection against electric shock
NOTE 1 It refers also to the action of insulating.

NOTE 2 Under certain circumstances, the heat insulation materials employed for electroheat equipment may
equally perform the function of the electrical insulation.
3.2.6
electrical connection
means or actual condition that allows or ensures the passage of electric current between two
conductive parts
3.2.7
fixed connection
connection of electroheat equipment to permanently-fixed supply circuits requiring the use of a
tool for mounting and dismantling purposes
NOTE In all other cases, the connection is removable.

60519-1  IEC:2003(E) – 11 –
3.2.8
equipotential bonding
provision of electric connections between conductive parts, intended to put them at a

substantially equal potential
[IEV 195-01-10, modified]
3.2.9
exposed-conductive part
conductive part of equipment which can be touched and which is not normally live, but which
can become live when basic insulation fails

[IEV 195-06-10]
3.2.10
protective conductor
(identification: PE)
conductor provided for the purposes of safety, for example protection against electric shock
[IEV 195-02-09, modified]
NOTE In an electrical installation, the PE conductor is normally also considered as a protective earthing
conductor.
3.2.11
protective earthing conductor
protective grounding conductor (US)
equipment grounding conductor (US)
protective conductor provided for protective earthing
[IEV 195-02-11, modified]
3.2.12
PEN conductor
conductor combining the functions of both a protective earthing conductor and a neutral
conductor
[IEV 195-02-12]
NOTE The acronym PEN results of the combination of both symbols PE for the protective conductor and N for the
neutral conductor.
3.2.13
earthing conductor
grounding conductor (US)
earth conductor (deprecated)
conductor which provides a conductive path, or part of the conductive path, between a given
point in a system or in an installation or in equipment and an earth electrode
[IEV 195-02-03]
3.2.14
leakage current (in an installation)
electric current which flows to earth or to extraneous conductive parts under normal operating
conditions
[IEV 195-05-15, modified]
NOTE 1 This current may have capacitive components including that resulting from the deliberate use of
capacitors.
NOTE 2 The value of the leakage current may differ in the hot and cold state of the installation.

– 12 – 60519-1  IEC:2003(E)
3.2.15
isolation
function intended to cut off for reasons of safety the supply from all or a discrete section of the

electrical installation by separating the electrical installation or section from every source of

electrical energy
[IEV 826-08-01, modified]
NOTE Switched-off parts are to be grounded (see 16.4).

3.2.16
switching-off for mechanical maintenance

operation intended to inactivate an item or items of electrically powered equipment for the
purpose of preventing a hazard other than that due to electric shock or to arcing, during non-
electrical work on the equipment
[IEV 826-08-02, modified]
NOTE Switched-off parts are grounded (see 16.4).
3.2.17
emergency switching-off
operation intended to remove electric power from an electrical installation to avert or alleviate a
hazardous situation
[IEV 826-08-03, modified]
3.2.18
functional switching
operation intended to switch "on" or "off" or vary the supply of electrical energy to an electrical
installation or parts of it for normal operating purposes
[IEV 826-08-05, modified]
3.2.19
photocoupler
optocoupler
optoelectronic device designed for the transfer of electrical signals by utilizing optical radiation
to provide coupling while the output is isolated from the input
[IEV 521-04-45]
NOTE This device provides immunity against electromagnetic influences as well as independence of the distance
of the two voltage system levels.

3.2.20
direct contact
electric contact of persons or animals with live parts
[IEV 195-06-03]
3.2.21
indirect contact
electric contact of persons or animals with exposed-conductive parts which have become live
under fault conditions
[IEV 195-06-04]
60519-1  IEC:2003(E) – 13 –
3.2.22
residual voltage (on a capacitor)
voltage remaining between the terminals of a capacitor at a given time after the disconnection

of the supply
[IEC 60110-1, 1.3.24, modified]

NOTE For static charges, see 6.3.1.

4 Classification of electroheat equipment according to voltage bands

4.1 Voltage classification
Electroheat equipment is classified according to the voltage(s) at which it is supplied under
normal operating conditions.
4.2 Voltage bands
According to the voltage specified in 4.1, electroheat equipment or part of it is classified as
follows:
4.2.1 Equipment of voltage band 1
Equipment with rated voltage not exceeding 50 V a.c. or 120 V smooth d.c.
4.2.2 Equipment of voltage band 2
Equipment with rated voltage above 50 V a.c. but not exceeding 1 000 V a.c. or above 120 V
smooth d.c. but not exceeding 1 500 V smooth d.c.
4.2.3 Equipment of voltage band 3
Equipment with rated voltage above 1 000 V a.c. or 1 500 V smooth d.c.
NOTE For the purpose of this standard for equipment of voltage band 3, see Clause 1 and 6.1.1.
5 Classification of electroheat equipment according to frequency bands
Electroheat equipment is classified according to frequency bands as follows:
5.1 Direct current equipment
Equipment operating at 0 Hz (direct current).
5.2 Low-frequency equipment
Equipment operating at frequencies not greater than 60 Hz (excluding mains frequency).
5.3 Mains-frequency equipment
Equipment operating at frequency of the a.c. public supply, usually 50 Hz or 60 Hz.
5.4 Medium-frequency equipment
Equipment operating at frequencies greater than mains frequency but less than or equal to
10 kHz.
– 14 – 60519-1  IEC:2003(E)
5.5 High-frequency equipment
Equipment operating at frequencies greater than 10 kHz but less than or equal to 300 MHz.

5.6 Microwave equipment
Equipment operating at frequencies greater than 300 MHz but less than or equal to 300 GHz.

6 General requirements
6.1 Electroheat equipment
6.1.1 All parts of electroheat equipment shall be designed, constructed and installed for the
voltages and frequencies used (d.c. included), taking into account the mode of operation, the
relevant IEC standards and the relevant instructions.
The equipment shall not be used under operating conditions other than those for which it has
been designed.
For voltage band 3, electroheat equipment with rated voltage not exceeding 3 600 V a.c. or
5 000 V d.c., insulation distances along surfaces and/or in air shall take into account the
ionization phenomena which could occur, at high temperatures under high electric fields, in
case of metallic vapour emission, splashes, pollution, etc.
NOTE 1 As an example, for equipment for which the rated frequency has been defined, but whose frequency may
vary within a certain range, the most unfavourable frequency for safety requirements should be considered.
NOTE 2 Special attention should be paid to the fact that in some cases, for example in equipment with resonant
circuits, the voltage may exceed its rated value due to resonance phenomena. The consequences for the
compliance with absolute maximum voltage limits are to be dealt with in the particular requirements.
6.1.2 Electroheat equipment shall be so designed and constructed that when installed and
used in accordance with the manufacturer's instructions, no hazard for the personnel or the
environment can arise.
In particular, and if necessary, by agreement between the manufacturer and user, anticipated
conditions at site leading to danger such as mechanical shocks, vibrations, excessive heating,
moisture, pressure, chemical actions, noise and dust, etc. shall be considered.
6.1.3 Electroheat equipment shall be so constructed and installed as to be sufficiently stable
during operation and in normal positions in which it may be used. Handles, operating levers
and the like shall be reliably fixed and secured.

The movement of levers and controls shall, as far as possible, correspond with the direction of
the mechanical movements they control.
6.1.4 Measures shall be taken to avoid abnormal overpressure, for example by safety valves
or temperature limiters.
6.1.5 Tilting, swivelling or movable electroheat equipment shall be so designed that the
electrical equipment and the pertinent auxiliary parts, when in either of the end positions or in
motion, are not mechanically overstressed.

60519-1  IEC:2003(E) – 15 –
6.2 Electrical equipment of electroheat installations

6.2.1 Electrical equipment shall be designed and constructed to ensure, under normal

operating conditions, the safety of personnel and the prevention of risks of fire and explosion.

The equipment shall also have sufficient mechanical strength to obviate the risks of

deterioration to which it may be liable.

Furthermore, it shall be so constructed that at all points the currents flowing under normal

operating conditions will not cause dangerous heating of conductors, insulation or nearby parts

of the electroheat installation.

Electrical equipment shall comply with the relevant IEC standards as far as they exist and
apply. It shall also comply with the requirements for electroheat installations and/or equipment.
6.2.2 Protective measures against electric shock shall be taken (see Clause 9).
6.2.3 Circuits comprising transformers, inductors and capacitors shall be designed to obviate
the occurrence of excessive voltages or currents which if maintained, could cause deterioration
of the said parts of these circuits and potentially constitute a hazard to persons.
6.2.4 Provisions to avoid hazards due to energies stored in capacitors and inductive
components during or after switch-off shall be taken. Protection against residual voltages on
capacitors shall be provided by effective discharge of capacitors. Guidance may be taken from
relevant standards, for example IEC 60110-1, IEC 60204-1 or specific standards for power
generators and/or capacitors not covered by IEC 60110-1. Appropriate instructions for the
users, if necessary, shall be given in the operating manual and according to the circumstances
by a warning label on the equipment.
6.2.5 When capacitors are assembled in banks, the manufacturer's instructions shall be
followed.
6.2.6 The electrical equipment chosen shall be so arranged that it does not deteriorate in
normal operation due to physical and chemical effects, such as those due to heat from the
environment, spatter of melted materials and salts, humidity, oil, shocks or friction. If
necessary, suitable structural measures shall be taken, for example by providing gutters,
protective channels and similar means.
6.2.7 To facilitate efficient inspection and maintenance, the various parts of the electrical
equipment, and particularly those parts liable to wear, shall as far as possible be easily
accessible.
6.2.8 Where forced cooling of components is employed, provision shall be made for
monitoring the cooling action. Should the cooling be insufficient, an alarm shall be given and, if
necessary, the electroheat equipment shall be switched off or safety otherwise ensured.
6.2.9 Sensors of temperature controllers, temperature limiters and temperature protectors
shall be attached so that they respond correctly and so that their operation is not impaired by
the temperature effect of the environment or by mechanical or inductive effects.
6.2.10 Push buttons shall be in accordance with 10.2 of IEC 60204-1.
6.2.11 Indicator lights and displays shall be in accordance with 10.3 of IEC 60204-1.
6.2.12 Devices for emergency switching-off shall be in accordance with 10.8 of IEC 60204-1.

– 16 – 60519-1  IEC:2003(E)
6.3 Static charges – Stray fields – Electric and/or magnetic fields

6.3.1 Static charges, which may impair the efficient operation of electroheat equipment or be

dangerous to persons, shall be suppressed or made harmless, for example by means of

earthing, screening or provision of sufficient distance.

6.3.2 Special precautions shall also be taken concerning the effects of electromagnetic

leakage (stray fields), for example eddy currents and/or induced voltages.

6.4 Impact of electromagnetic effects

6.4.1 Electromagnetic disturbances created by electroheat equipment shall be within the
limits given in CISPR 11, as far as it applies.
6.4.2 Effects of harmonic currents shall be taken into account, if necessary.
NOTE 1 Information on emission for low-voltage equipment with a rated input current less or equal to 16 A can be
found in IEC 61000-3-2.
NOTE 2 For the evaluation of the type and amount of harmonics, the characteristics of the supply system are to
be taken into account.
NOTE 3 Information on the limitation of harmonic currents for equipment with a rated current greater than 16 A
can be found in IEC 61000-3-4.
NOTE 4 Information on the limitation of distorting loads in medium-voltage and high-voltage power systems can be
found in IEC 61000-3-6.
6.4.3 Voltage fluctuation and flicker shall be taken into account, if necessary.
NOTE 1 Information on voltage fluctuation and flicker for equipment with a rated input current less or equal to
16 A can be found in IEC 61000-3-3.
NOTE 2 For the evaluation of voltage fluctuation and flicker the characteristics of the supply system are to be
taken into account.
NOTE 3 Information on the limitation of voltage fluctuations and flicker for equipment with a rated input current
greater than 16 A can be found in IEC 61000-3-5, and for equipment with a rated input current less or equal to 75 A,
see also IEC 61000-3-11.
NOTE 4 Information on the limitation of fluctuating loads in medium-voltage and high-voltage power systems can
be found in IEC 61000-3-7.
6.4.4 Immunity to electromagnetic fields shall be taken into account if necessary. Special
requirements are under consideration.
NOTE General information on immunity requirements for industrial equipment may be taken from IEC 61000-6-2.
6.4.5 The electroheat equipment shall be designed and operated so as to protect the

operators from any harmful effect of the electromagnetic field emitted from electroheat
equipment.
NOTE Further information can be found in, for example ICNIRP Guidelines (Basic restriction): Guidelines for
limiting exposure to time varying electric, magnetic and electromagnetic fields (up to 300 GHz), and in national
regulations.
6.5 Ionizing radiation
Devices and components for measurement or monitoring of electroheat equipment emitting
ionizing radiation shall comply with the statutory provisions for protection. This also applies to
the charge of the electroheat installations.
NOTE Further information can be found in, for example ICRP Publication 60: Recommendations of the
International Commission on Radiological Protection, and in national regulations.

60519-1  IEC:2003(E) – 17 –
6.6 Liquid cooling
6.6.1 Where live parts are liquid-cooled, for example inductors, transformers, capacitors,

busbars, cables as well as boiler or machinery parts, the quality of the coolant, the length of

the hoses and the material used for tubes and hoses shall be such that the touch voltage due

to leakage currents shall not exceed the safety level.

NOTE Special attention may need to be given to hose fittings employed.

6.6.2 The formation of bubbles in cooling systems shall be avoided as far as possible.

6.6.3 Closed circuit cooling is preferred to reduce the risk of coolant contamination and loss.
6.6.4 All parts through which the coolant flows shall be designed to withstand 1,5 times the
rated operational pressure.
NOTE Provisions for special devices, which accordingly to their manufacturers information may not withstand this
test pressure, are given in particular requirements.
6.6.5 Precautions should be taken to limit the formation of deposits, corrosion and gases. The
formation of condensation shall be avoided as far as possible. Galvanic effects on the hose
connectors shall be checked.
6.6.6 The manufacturer of the installation shall give the following cooling data:
– type and quality of the coolant (physical, chemical and electrical properties);
– required flow rate;
– minimum and maximum inlet and maximum outlet temperatures;
– required minimum pressure difference between inlet and outlet.
7 Isolation and switching
Isolation, switching-off for mechanical maintenance, emergency switching, and functional
switching (control) shall be provided and be in accordance with the relevant standards, for
example IEC 60364-4-41, IEC 60364-5-53 and IEC 60204-1.
7.1 Switching-off of special circuits
Depending on the application, there may be circuits which need not be switched off such as:

a) lighting and socket-outlet circuits for the connection of repair and maintenance tools, for
example lamps, drills (irrespective of their voltage);
b) circuits supplying undervoltag
...