SIST EN 60519-2:2007

Safety in electroheat installations -- Part 2: Particular requirements for resistance heating equipment

This part of IEC 60519 is applicable to the indirect resistance heating equipment and the direct resistance heating equipment specified in items a) and b) below respectively, operating in voltage bands 1 and 2. The object of this standard is the standardization of safety requirements for both indirect and direct resistance heating equipment described below. These particular requirements apply to equipment for indirect resistance heating, such equipment being energized with d.c. voltage or with single-phase or multiphase a.c. voltage of frequency up to 60 Hz. Heat generation is effected by current flow in ? solid metallic heating conductors; ? solid non-metallic heating conductors; ? radiant tubes and immersion heaters. Examples of indirect resistance heating equipment in general use include ? discontinuous furnaces such as batch-type furnaces, muffle furnaces, pot-type furnaces (crucible furnaces), pit-type furnaces, bell-type furnaces, bogie-hearth furnaces, fluidizedbed furnaces, immersion heater metal baths; ? continuous furnaces with continuous or discontinuous charge conveyors, such as rollerhearth furnaces, pusher furnaces, walking-beam furnaces, rotary-retort furnaces, rotaryhearth furnaces, tunnel furnaces (kilns), continuous muffle furnaces. Indirect resistance heating equipment in general use also includes ? equipment for heating solids, liquids or gases; ? equipment for melting and holding; ? individual heating-element assemblies (movable or fixed heaters). Indirect resistance heating equipment where particular hazards are likely to occur includes ? nitrite bath furnaces; ? indirect resistance heating equipment where an explosive atmosphere is likely to occur inside the furnace during heat treatment: furnaces for carburizing in gas atmospheres consisting of the mixture of hydrogen and methane or propane and carbon monoxide.

Sicherheit in Elektrowärmeanlagen - Teil 2: Besondere Anforderungen an Einrichtungen mit Widerstandserwärmung

Sécurité dans les installations électrothermiques -- Partie 2: Exigences particulières pour les installations de chauffage par résistance

Normalise les exigences de sécurité pour les installations de chauffage par résistance. Est applicable aux installations de chauffage indirect et direct par résistance fonctionnant dans les domaines de tensions 1 et 2.

Varnost pri električnih grelnih inštalacijah – 2. del: Posebne zahteve za inštalacije za opremo uporovnega segrevanje (IEC 60519-2:2006)

General Information

• Status: Withdrawn
• Publication Date: 31-Dec-2006
• Withdrawal Date: 08-May-2019
• ICS: 25.180.10 - Electric furnaces
• Technical Committee: I09 - Imaginarni 09
• Current Stage: 9900 - Withdrawal (Adopted Project)
• Start Date: 09-May-2019
• Due Date: 01-Jun-2019
• Completion Date: 09-May-2019
• Directive: 2006/95/EC - Directive 2006/95/EC of the European Parliament and of the Council of 12 December 2006 on the harmonisation of the laws of Member States relating to electrical equipment designed for use within certain voltage limits (codified version)
• Directive: 2014/35/EU - Directive 2014/35/EU of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of electrical equipment designed for use within certain voltage limits
• Directive: 73/23/EEC - Electrical equipment designed for use within certain voltage limits
• Ref Project: EN 60519-2:2006 - Safety in electroheat installations - Part 2: Particular requirements for resistance heating equipment

Relations

• Replaces: SIST EN 60519-2:1999 - Safety in electroheat installations -- Part 2: Particular requirements for resistance heating equipment
• Effective Date: 01-Sep-2009
• Replaces: SIST EN 60519-2:1999 - Safety in electroheat installations -- Part 2: Particular requirements for resistance heating equipment
• Effective Date: 28-Jan-2023
• Replaces: SIST EN 60519-2:1999 - Safety in electroheat installations -- Part 2: Particular requirements for resistance heating equipment
• Effective Date: 06-May-2014

Standards Content (Sample)

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---------------------- Page: 1 ----------------------

EUROPEAN STANDARD
EN 60519-2

NORME EUROPÉENNE
September 2006
EUROPÄISCHE NORM

ICS 25.180.10 Supersedes EN 60519-2:1993


English version


Safety in electroheat installations
Part 2: Particular requirements
for resistance heating equipment
(IEC 60519-2:2006)


Sécurité dans les installations Sicherheit in Elektrowärmeanlagen
électrothermiques Teil 2: Besondere Anforderungen an
Partie 2: Exigences particulières Einrichtungen mit Widerstandserwärmung
pour les installations de chauffage (IEC 60519-2:2006)
par résistance
(CEI 60519-2:2006)




This European Standard was approved by CENELEC on 2006-09-01. CENELEC members are bound to comply
with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard
the status of a national standard without any alteration.

Up-to-date lists and bibliographical references concerning such national standards may be obtained on
application to the Central Secretariat or to any CENELEC member.

This European Standard exists in three official versions (English, French, German). A version in any other
language made by translation under the responsibility of a CENELEC member into its own language and notified
to the Central Secretariat has the same status as the official versions.

CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.

CENELEC
European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung

Central Secretariat: rue de Stassart 35, B - 1050 Brussels


© 2006 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60519-2:2006 E

---------------------- Page: 2 ----------------------

EN 60519-2:2006 - 2 -
Foreword
The text of document 27/525/FDIS, future edition 3 of IEC 60519-2, prepared by IEC TC 27, Industrial
electroheating equipment, was submitted to the IEC-CENELEC parallel vote and was approved by
CENELEC as EN 60519-2 on 2006-09-01.
This European Standard supersedes EN 60519-2:1993.
Significant changes with respect to EN 60519-2:1993 are as follows:
– the structure has been adjusted to the latest ISO/IEC Directives;
– the latest edition of EN 60519-1 has been taken into account;
– definitions have been brought into line with the second edition of IEC 60050-841.
This standard shall be used in conjunction with EN 60519-1:2003. It is intended to modify, replace or
make additions to EN 60519-1 for particular requirements for resistance heating equipment.
The following dates were fixed:
– latest date by which the EN has to be implemented
at national level by publication of an identical
(dop) 2007-06-01
national standard or by endorsement
– latest date by which the national standards conflicting
(dow) 2009-09-01
with the EN have to be withdrawn
Annex ZA has been added by CENELEC.
__________
Endorsement notice
The text of the International Standard IEC 60519-2:2006 was approved by CENELEC as a European
Standard without any modification.
__________

---------------------- Page: 3 ----------------------

- 3 - EN 60519-2:2006
Annex ZA
(normative)

Normative references to international publications
with their corresponding European publications

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.

NOTE  When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD
applies.

Publication Year Title EN/HD Year

IEC 60050-841 2004 International electrotechnical vocabulary - -
Part 841: Industrial electroheat


IEC 60335-1 (mod) 2001 Household and similar electrical appliances - EN 60335-1 2002
A1 2004 Safety A1 2004
Part 1: General requirements A11 2004
A12 2006
+ corr. July 2006


IEC 60364-4-41 2005 Low-voltage electrical installations - -
Part 4-41: Protection for safety - Protection
against electric shock


IEC 60364-4-42 2001 Electrical installations of buildings - -
Part 4-42: Protection for safety - Protection
against thermal effects


IEC 60398 1999 Industrial electroheating installations - EN 60398 1999
General test methods


IEC/TS 60479-1 2005 Effects of current on human beings and - -
livestock
Part 1: General aspects


IEC 60519-1 2003 Safety in electroheat installations EN 60519-1 2003
Part 1: General requirements


IEC 60519-3 2005 Safety in electroheat installations EN 60519-3 2005
Part 3: Particular requirements for induction
and conduction heating and induction melting
installations


IEC 60519-4 1995 Safety in electroheat installations EN 60519-4 1997
A1 2000 Part 4: Particular requirements for arc furnace A1 2000
installations


IEC 60519-8 2005 Safety in electroheat installations EN 60519-8 2005
Part 8: Particular requirements for electroslag
remelting furnaces


IEC 60519-10 2005 Safety in electroheat installations - -
Part 10: Particular requirements for electrical
resistance trace heating systems for industrial
and commercial applications

---------------------- Page: 4 ----------------------

EN 60519-2:2006 - 4 -
Publication Year Title EN/HD Year
IEC 60519-21 1998 Safety in electroheat installations EN 60519-21 1998
Part 21: Particular requirements for
resistance heating equipment - Heating and
melting glass equipment


IEC 60529 1989 Degrees of protection provided by enclosures EN 60529 1991
- - (IP Code) + corr. May 1993
A1 1999 A1 2000


IEC 60990 1999 Methods of measurement of touch current EN 60990 1999
and protective conductor current


IEC 61140 2001 Protection against electric shock - Common EN 61140 2002
aspects for installation and equipment

---------------------- Page: 5 ----------------------

NORME CEI
INTERNATIONALE
IEC



60519-2
INTERNATIONAL


Troisième édition
STANDARD

Third edition

2006-08


Sécurité dans les installations électrothermiques –
Partie 2:
Exigences particulières pour les installations
de chauffage par résistance

Safety in electroheat installations –
Part 2:
Particular requirements for resistance
heating equipment
 IEC 2006 Droits de reproduction réservés  Copyright - all rights reserved
Aucune partie de cette publication ne peut être reproduite ni No part of this publication may be reproduced or utilized in any
utilisée sous quelque forme que ce soit et par aucun procédé, form or by any means, electronic or mechanical, including
électronique ou mécanique, y compris la photocopie et les photocopying and microfilm, without permission in writing from
microfilms, sans l'accord écrit de l'éditeur. the publisher.
International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
CODE PRIX
Q
PRICE CODE
Commission Electrotechnique Internationale
International Electrotechnical Commission
МеждународнаяЭлектротехническаяКомиссия
Pour prix, voir catalogue en vigueur
For price, see current catalogue

---------------------- Page: 6 ----------------------

60519-2  IEC:2006 – 3 –
CONTENTS
FOREWORD.5

1 Scope and object.9
2 Normative references .11
3 Terms and definitions .13
4 Classification of electroheat equipment according to voltage bands.17
5 Classification of electroheat equipment according to frequency bands.17
6 General requirements .17
6.7 Resistivity .17
6.8 Auxiliary equipment .17
6.9 Bare heating conductors.19
6.10 Leakage current .19
6.11 Vapours, precipitates and sediments from the charge.19
6.12 Salt-bath furnaces and melting furnaces.19
6.13 Heating-up solidified contents of the bath.21
6.14 Vacuum furnaces .21
7 Isolation and switching .21
8 Connection to the supply network and internal connections .21
9 Protection against electric shock .21
9.5 Protection against direct contact .21
9.6 Protection against direct and indirect contact .23
10 Protection against overcurrent.25
11 Equipotential bonding .25
12 Control circuits and control functions .25
13 Protection against thermal influences .25
13.6 Surface temperature of resistance heating equipment .25
13.7 Special measures.27
13.8 Temperature safety devices .27
13.9 Nitrite and nitrate bath furnaces .27
14 Risk of fire and danger of explosion.29
14.1 Nitrite and nitrate bath furnaces .29
15 Marking, labelling and technical documentation .29
15.2 Labelling .31
15.3 Technical documentation.31
16 Information on inspection and commissioning and instructions for utilization and
maintenance of electroheat installations .31
16.2 Information on inspection and commissioning.31
16.3 Instructions for utilization to be given in the technical documentation .33

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60519-2  IEC:2006 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________

SAFETY IN ELECTROHEAT INSTALLATIONS –

Part 2: Particular requirements for resistance heating equipment


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, Publicly Available Specifications (PAS) 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 60519-2 has been prepared by IEC technical committee 27:
Industrial electroheating equipment.
This third edition cancels and replaces the second edition published in 1992 and constitutes a
technical revision. Significant changes with respect to the previous edition are as follows:
– the structure has been adjusted to the latest ISO/IEC Directives;
– the latest edition of IEC 60519-1 has been taken into account;
– definitions have been brought into line with the second edition of IEC 60050-841.
This standard shall be used in conjunction with IEC 60519-1:2003. It is intended to modify,
replace or make additions to IEC 60519-1 for particular requirements for resistance heating
equipment.

---------------------- Page: 8 ----------------------

60519-2  IEC:2006 – 7 –
The text of this standard is based on the following documents:
FDIS Report on voting
27/525/FDIS 27/541/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.
A list of all parts of IEC 60519 series, under the general title Safety in electroheat
installations, can be found on the IEC website.
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in
the data related to the specific publication. At this date, the publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

---------------------- Page: 9 ----------------------

60519-2  IEC:2006 – 9 –
SAFETY IN ELECTROHEAT INSTALLATIONS –

Part 2: Particular requirements for resistance heating equipment



1 Scope and object
This part of IEC 60519 is applicable to the indirect resistance heating equipment and the
direct resistance heating equipment specified in items a) and b) below respectively, operating
in voltage bands 1 and 2.
The object of this standard is the standardization of safety requirements for both indirect and
direct resistance heating equipment described below.
a) Indirect resistance heating equipment
These particular requirements apply to equipment for indirect resistance heating, such
equipment being energized with d.c. voltage or with single-phase or multiphase a.c. voltage of
frequency up to 60 Hz.
Heat generation is effected by current flow in
− solid metallic heating conductors;
− solid non-metallic heating conductors;
− radiant tubes and immersion heaters.
Examples of indirect resistance heating equipment in general use include
− discontinuous furnaces such as batch-type furnaces, muffle furnaces, pot-type furnaces
(crucible furnaces), pit-type furnaces, bell-type furnaces, bogie-hearth furnaces, fluidized-
bed furnaces, immersion heater metal baths;
− continuous furnaces with continuous or discontinuous charge conveyors, such as roller-
hearth furnaces, pusher furnaces, walking-beam furnaces, rotary-retort furnaces, rotary-
hearth furnaces, tunnel furnaces (kilns), continuous muffle furnaces.
Indirect resistance heating equipment in general use also includes
− equipment for heating solids, liquids or gases;
− equipment for melting and holding;
− individual heating-element assemblies (movable or fixed heaters).
Indirect resistance heating equipment where particular hazards are likely to occur includes
− nitrite bath furnaces;
− indirect resistance heating equipment where an explosive atmosphere is likely to occur
inside the furnace during heat treatment: furnaces for carburizing in gas atmospheres
consisting of the mixture of hydrogen and methane or propane and carbon monoxide;

---------------------- Page: 10 ----------------------

60519-2  IEC:2006 – 11 –
− indirect resistance heating equipment with protective gas and/or reaction gas atmosphere:
furnaces for gas carburizing, gas nitriding, carbo-nitriding (protective gas, for example,
argon);
− equipment with infrared heating elements.
These requirements do not apply to trace heating systems dealt with in IEC 60519-10.
b) Direct resistance heating equipment
These particular requirements also apply to equipment for direct resistance heating by means
of current introduced by electrodes passing through the charge or a fluid to be heated. Such
equipment includes, for example,
− salt-bath electrode furnaces;
− glass-melting furnaces;
− furnaces for graphitizing;
− furnaces for production of silicon carbide.
These requirements do not apply to equipment for direct resistance heating, where, owing to
the technology used, IEC 60519-3, IEC 60519-4, IEC 60519-8 and IEC 60519-21 are
applicable. Moreover, they do not apply to electrode-steam-boiler instantaneous water
heaters and electrode pressure vessels.
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 60050-841:2004, International Electrotechnical Vocabulary (IEC) – Part 841: Industrial
electroheat
IEC 60335-1:2000, Household and similar electrical appliances – Safety – Part 1: General
requirements
1
Amendment 1 (2004)
IEC 60364-4-41:2005, Low-voltage electrical installations – Part 4-41: Protection for safety –
Protection against electric shock
IEC 60364-4-42:2001, Electrical installations of buildings – Part 4-42: Protection for safety –
Protection against thermal effects
IEC 60398:1999, Industrial electroheating installations – General test methods
IEC 60479-1:2005, Effects of current on human beings and livestock – Part 1: General
aspects
IEC 60519-1:2003, Safety in electroheat installations – Part 1: General requirements
___________
1
There exists a consolidated edition 4.1 (2004) that includes edition 4 and its amendment 1.

---------------------- Page: 11 ----------------------

60519-2  IEC:2006 – 13 –
IEC 60519-3:2005, Safety in electroheat installations – Part 3: Particular requirements for
induction and conduction heating and induction melting installations
IEC 60519-4:2000, Safety in electroheat installations – Part 4: Particular requirements for arc
furnace installations
IEC 60519-8:2005, Safety in electroheat installations – Part 8: Particular requirements for
electroslag remelting furnaces
IEC 60519-10:2005, Safety in electroheat installations – Part 10: Particular requirements for
electrical resistance trace heating systems for industrial and commercial applications
IEC 60519-21:1998, Safety in electroheat installations – Part 21: Particular requirements for
resistance heating equipment – Heating and melting glass equipment
IEC 60529:2001, Degrees of protection provided by enclosures (IP Code)
IEC 60990:1999, Methods of measurement of touch current and protective conductor current
IEC 61140:2001, Protection against electric shock – Common aspects for installation and
equipment
3 Terms and definitions
For the purposes of this document, the following terms and definitions, as well as those given
in IEC 60519-1 and IEC 60050-841, apply.
3.1
electrode (for direct resistance heating)
part of direct resistance heating which, being in contact with the charge, transfers the current
to it
3.2
heating conductor
conductor used for conversion of electric energy into heat
NOTE The term "heating conductor" is often used interchangeably with "heating resistor" [IEV 841-23-13].
3.3
glass-melting furnace (direct resistance heating)
furnace in which the melting of glass is effected by the heat generated by the direct flow of
current in the bath, in which the electrodes are immersed
3.4
salt-bath furnace
furnace in which a salt bath is principally used as a heat-transfer fluid
NOTE Heating may be effected by direct or indirect heating. Direct heating is effected when the heating-element
assemblies (heaters) are located in the salt bath (immersed heaters, electrodes). Indirect heating is effected when
the heating-element assemblies (heaters) are located outside the tank or crucible.

---------------------- Page: 12 ----------------------

60519-2  IEC:2006 – 15 –
3.5
nitrite and nitrate bath furnace
salt-bath furnace containing, in metallic tanks or crucibles, potassium or sodium nitrate or
nitrite baths or baths composed of a mixture of these salts
3.6
pre-heating equipment (for bath furnaces)
auxiliary heating devices which ensure that the upper layer of the bath is melted first when the
bath has reached a state of solidification
3.7
melting furnace
furnace used for melting solid charges
3.8
holding-temperature furnace
furnace used for maintaining in a molten state, at predetermined temperature, charges
introduced in the furnace in a melted state
3.9
heat transfer fluid
liquid or gas used for transferring heat from the heating-element assembly (heater) to the
charge
3.10
removable heating element, removable heating-element assembly (heater)
heating element and/or heating-element assembly (heater), which can be removed or
replaced by the user without dismantling any other parts, for example, thermal insulation,
refractories of the furnace
NOTE Heating elements and/or heating-element assemblies (heaters) are "removable in service" when they can
be removed in service without interrupting the operating process.
3.11
thermal cut-out and temperature protector
devices which switch off the heating equipment when pre-determined temperatures are
exceeded
NOTE Thermal cut-outs are resettable; temperature protectors are not resettable and are replaced each time they
have operated.
3.12
pre-selected temperature limiter
device which switches off the heating equipment when the pre-selected temperature of the
equipment (working temperature) is exceeded by a predetermined value and which retains the
equipment in the de-energized state
NOTE Pre-selected temperature limiters are set, locked or reset only by a skilled person.
3.13
pre-selected temperature controller
device which controls the furnace temperature so that it does not exceed or fall below the pre-
selected temperature by a predetermined value
NOTE Pre-selected temperature controllers are set or locked only by a skilled person.

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60519-2  IEC:2006 – 17 –
3.14
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 the cold state of the installation.
3.15
touch current
electric current passing through a human body or through an animal body when it touches one
or more accessible parts of an installation or equipment
[IEV 195-05-21]
3.16
protective conductor current
current which flows in a protective conductor
[IEC 60990, 3.2]
3.17
immersion heater
electrical heating element in which the heat is transmitted to the bath through the insulation
and protective sheath
NOTE The immersion heater may be stationary or movable.
4 Classification of electroheat equipment according to voltage bands
Subclauses 4.2.1 and 4.2.2 of IEC 60519-1 apply.
5 Classification of electroheat equipment according to frequency bands
Clause 5 of IEC 60519-1 applies.
6 General requirements
The requirements of Clause 6 of IEC 60519-1 apply except as follows.
Additional subclauses:
6.7 Resistivity
In some cases changes of resistance of the heating conductors (in the case of indirect
resistance heating) or resistance of the charge (in the case of direct resistance heating)
during operation, shall be taken into account when dimensioning and choosing electroheat
equipment.
6.8 Auxiliary equipment
Precautions shall be taken to ensure that auxiliary equipment, for example, handling,
transport and charging devices, does not constitute a source of danger.

---------------------- Page: 14 ----------------------

60519-2  IEC:2006 – 19 –
6.9 Bare heating conductors
In general, bare heating conductors shall be so placed that under normal operating
conditions, they cannot come into contact with persons, the charge or the charge handling
equipment. Exception can be made for those bare conductors supplied from sources which
comply with the requirements for safety extra-low voltage (SELV) supplied in accordance with
IEC 60364-4-41.
6.10 Leakage current
Protective measures adopted shall be so chosen that persons are not exposed to the risk of
electrical hazards due to leakage current arising under normal operating conditions.
Effective measures shall be taken to ensure that the leakage current which flows either
through the furnace including the charge or through the charge does not cause electrical
hazards of any kind.
6.11 Vapours, precipitates and sediments from the charge
If vapours, precipitates, sediments and the like are produced from the charge, their possible
physical and chemical effects on persons and/or on the heating equipment shall be taken into
account.
6.12 Salt-bath furnaces and melting furnaces
6.12.1  In the case of furnaces with salt bath and other baths such as galvanizing or
aluminium holding baths, the maximum permissible rated voltage for immersed heaters shall
be 400 V.
6.12.2  The maximum permissible temperature of the bath shall be clearly indicated on the
temperature indicator or on the temperature controller (see 13.9.1).
6.12.3  Nitrite bath furnaces intended for the treatment of aluminium or wrought aluminium
alloys shall not be used for charges made of
– cast aluminium alloys;
– aluminium alloys of unknow
...