EN IEC 63078:2020

SLOVENSKI STANDARD
01-maj-2020
Naprave za električno ogrevanje in elektromagnetno obdelavo - Preskusne metode
za indukcijske naprave za segrevanje (IEC 63078:2019)
Installations for electroheating and electromagnetic processing - Test methods for
induction through-heating installations (IEC 63078:2019)
Elektrowärmeanlagen und Anlagen für elektromagnetische Bearbeitungsprozesse -
Prüfverfahren für induktive Durcherwärmungsanlagen (IEC 63078:2019)
Installations pour traitement électrothermique et électromagnétique - Méthodes d'essai
pour les installations de chauffage par induction (IEC 63078:2019)
Ta slovenski standard je istoveten z: EN IEC 63078:2020
ICS:
25.180.10 Električne peči Electric furnaces
97.100.01 Grelniki na splošno Heating appliances in
general
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 63078

NORME EUROPÉENNE
EUROPÄISCHE NORM
February 2020
ICS 25.180.10
English Version
Installations for electroheating and electromagnetic processing -
Test methods for induction through-heating installations
(IEC 63078:2019)
Installations pour traitement électrothermique et Elektrowärmeanlagen und Anlagen für elektromagnetische
électromagnétique - Méthodes d'essai pour les installations Bearbeitungsprozesse - Prüfverfahren für induktive
de chauffage par induction Durcherwärmungsanlagen
(IEC 63078:2019) (IEC 63078:2019)
This European Standard was approved by CENELEC on 2019-12-27. 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 CEN-CENELEC
Management Centre 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 CEN-CENELEC Management Centre has the
same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic,
Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the
Netherlands, Norway, Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland,
Turkey and the United Kingdom.

European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique
Europäisches Komitee für Elektrotechnische Normung
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2020 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 63078:2020 E
European foreword
The text of document 27/1118/FDIS, future edition 1 of IEC 63078, prepared by IEC/TC 27 "Industrial
electroheating and electromagnetic processing" was submitted to the IEC-CENELEC parallel vote and
approved by CENELEC as EN IEC 63078:2020.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2020-09-27
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2022-12-27
document have to be withdrawn
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.

Endorsement notice
The text of the International Standard IEC 63078:2019 was approved by CENELEC as a European
Standard without any modification.
In the official version, for Bibliography, the following notes have to be added for the standards
indicated:
IEC 62076:2006 NOTE Harmonized as EN 62076:2006 (not modified)
IEC 60683:2011 NOTE Harmonized as EN 60683:2012 (not modified)

Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications
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.
NOTE 1  Where an International Publication has been modified by common modifications, indicated by (mod), the relevant
EN/HD applies.
NOTE 2  Up-to-date information on the latest versions of the European Standards listed in this annex is available here:
www.cenelec.eu.
Clause 2 of IEC 60398:2015 is applicable with the following additions:
Publication Year Title EN/HD Year
IEC 60398 2015 Installations for electroheating and EN 60398 2015
electromagnetic processing - General
performance test methods
1 2
IEC 60519-1 — Safety in installations for electroheating EN IEC 60519-1 —
and electromagnetic processing - Part 1:
General requirements
IEC 60519-3 2005 Safety in electroheat installations - Part 3: EN 60519-3 2005
Particular requirements for induction and
conduction heating and induction melting
installations
Under preparation. Stage at time of publication: IEC BPUB 60519-1:2020.
Under preparation. Stage at time of publication: FprEN IEC 60519-1:2019.
IEC 63078 ®
Edition 1.0 2019-11
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Installations for electroheating and electromagnetic processing – Test methods

for induction through-heating installations

Installations pour traitement électrothermique et électromagnétique – Méthodes

d'essai pour les installations de chauffage par induction

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.180.10 ISBN 978-2-8322-7583-2

– 2 – IEC 63078:2019 © IEC 2019
CONTENTS
FOREWORD . 3
INTRODUCTION . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
4 Basic provisions for testing and test conditions . 11
5 Comparing equipment or installations . 13
6 Measurements and workloads . 13
7 Numerical modelling . 14
8 List of tests . 14
9 Technical tests and efficiency of the installation . 15
Annex A (informative) Energy efficiency assessment . 19
Annex B (informative) Visual display of energy efficiency related information . 20
Annex C (informative) Estimating energy use . 21
Annex D (informative) Energy recoverability . 22
Annex AA (normative) Explanatory diagrams for symbols and definitions relating to the
power circuit of induction through-heating equipment . 23
Annex BB (informative) List of symbols used in this document . 27
Annex CC (normative) Determination of billet temperature homogeneity Δθ . 29
b
Annex DD (informative) Methods for safety tests . 34
Bibliography . 35

Figure AA.1 – Basic power circuit of the induction through-heating equipment . 23
Figure AA.2 – Power circuit of the induction through-heating equipment having one
rectifier transformer as well as several semiconductor frequency converters and
compensated circuits/loads . 24
Figure AA.3 – Power circuit of the induction through-heating equipment having one
rectifier transformer, one rectifier as well as several series type inverters and
compensated circuits/loads . 25
Figure AA.4 – Examples of compensated circuits . 26

Table CC.1 – Arrangement of temperature measuring points of the billets . 31

IEC 63078:2019 © IEC 2019 – 3 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INSTALLATIONS FOR ELECTROHEATING AND ELECTROMAGNETIC
PROCESSING – TEST METHODS FOR INDUCTION
THROUGH-HEATING INSTALLATIONS
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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity
assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any
services carried out by independent certification bodies.
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 63078 has been prepared by IEC technical committee 27:
Industrial electroheating and electromagnetic processing.
The text of this International Standard is based on the following documents:
FDIS Report on voting
27/1118/FDIS 27/1119/RVD
Full information on the voting for the approval of this International Standard can be found in
the report on voting indicated in the above table.
This document has been drafted in accordance with the ISO/IEC Directives, Part 2.
This International Standard is to be used in conjunction with IEC 60398:2015.

– 4 – IEC 63078:2019 © IEC 2019
The clauses of this document supplement, modify or replace clauses of IEC 60398. When this
document states “addition”, "modification" or “replacement”, the relevant text in IEC 60398 is
to be adapted accordingly.
Subclauses which are additional to those in IEC 60398 are numbered starting from 101.
Additional annexes are numbered AA, BB, etc.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC web site 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.
IEC 63078:2019 © IEC 2019 – 5 –
INTRODUCTION
Induction through-heating and induction melting are very important applications of induction
heating. However, an induction through-heating installation is more complex than an induction
melting furnace, as it includes more heating manners, varieties and sizes. In addition, some
performance tests which are very useful to users, for example the determination of
temperature homogeneity of billets and energy efficiency of the installation, are not easy to
carry out.
Induction through-heating installations are widely used in many industries for example
machine building and metallurgy, for heating billets or workpieces of alloy steel, copper,
aluminum, etc. before their subsequent hot forming (e.g. forging, extruding and rolling), with
clean and fast heating, easy temperature control and automation as well as a high degree of
energy-saving.
This document was prepared on the basis of IEC 60398:2015, with some references made to
IEC 62076:2006 and “Induction Heating – Industrial Applications” published by UIE in 1992.

– 6 – IEC 63078:2019 © IEC 2019
INSTALLATIONS FOR ELECTROHEATING AND ELECTROMAGNETIC
PROCESSING – TEST METHODS FOR INDUCTION
THROUGH-HEATING INSTALLATIONS
1 Scope
This clause of IEC 60398:2015 is replaced by the following.
This document specifies the test procedures, conditions and methods for determining the
main performance parameters and operational characteristics of induction through-heating
installations.
Measurements and tests that are solely used for the verification of safety requirements of the
installations are outside the scope of this document and are covered by IEC 60519-1 and
IEC 60519-3.
This document is applicable to the induction heating installations which through-heat the
whole or part of metal billet or workpiece for its subsequent hot forming (e.g. forging,
extruding and rolling), using low, mains or medium frequencies. It is possible to use it as a
reference for other induction heating installations for heat-treatment and other purposes as
well as superconducting DC induction through-heating installations.
This document includes the concept and material on energy efficiency dealing with the
electrical and processing parts of the installations, as well as the overall performance.
2 Normative references
This clause of IEC 60398:2015 is applicable except as follows.
Replacement:
The following standards are referred to in the text in such a way that some or all of their
contents constitutes requirements of this standard. For dated references, only the edition
cited applies. For undated references, the latest edition of the referenced standard (including
any amendments) applies.
Modification:
Delete footnotes
Additions:
IEC 60398:2015, Installations for electroheating and electromagnetic processing – General
performance test methods
IEC 60519-1:— , Safety in installations for electroheating and electromagnetic processing –
Part 1: General requirements
____________
Sixth edition under preparation. Stage at the time of publication: IEC PRVC 60519-1:2019.

IEC 63078:2019 © IEC 2019 – 7 –
IEC 60519-3:2005, Safety in electroheat installations – Part 3: Particular requirements for
induction and conduction heating and induction melting installations
3 Terms and definitions
This clause of IEC 60398:2015 is applicable except as follows.
Replacement:
For the purposes of this document, the terms and definitions given in IEC 60398:2015 and the
following 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
Additions:
NOTE 101 For the following definitions of terms related to some parts and electrical parameters of power circuit
of induction through-heating equipment, see also the explanatory diagrams in Annex AA. The symbols are also
listed in Annex BB.
3.101
induction through-heating installation
installation comprising induction through-heating equipment and the electrical and mechanical
auxiliaries necessary for the operation and utilization of the equipment
Note 1 to entry: The electrical auxiliaries comprise all electrical components in the power circuit of induction
through-heating equipment, power supply for mechanical auxiliaries and control system; and the mechanical
auxiliaries comprise billet handling mechanism and its mechanical power as well as water cooling system, etc.
3.102
induction through-heating equipment
equipment consisting of one or more heating inductors, supporting frames (cabinets) and the
connections for cooling water and electricity, etc., for induction heating and holding of billet
3.103
batch heating
repetitive static heating manner, which involves placing an individual billet into a heating
inductor for heating and holding, and then extracting it
[SOURCE: IEC 62076:2006, 3.39， modified – The differences between induction through-
heating and induction melting in workload name and technological process have been
considered.]
3.104
stage heating
heating manner having two or more heating inductors, in which, for a two heating inductor
equipment for example, the billet is firstly placed into a heating inductor for heating, secondly
moved to another heating inductor for holding and then extracted
3.105
continuous heating
heating manner, in which the billets progress continuously or rhythmically through one or
more heating inductors for heating and holding

– 8 – IEC 63078:2019 © IEC 2019
[SOURCE: IEC 62076:2006, 3.40， modified – The differences between induction through-
heating and induction melting in workload name and technological process have been
considered.]
3.106
lining
part of inductor, which is placed between the induction coil and heated
billet as a thermal insulation, and usually consists of a refractory layer and a temperature
holding layer or is directly formed by ramming or pouring refractory materials
3.107
power circuit of induction through-heating equipment
circuit consisting of the power source(s) and compensated circuit(s) of the induction through-
heating equipment, including the conductors connecting both
3.108
power source
equipment for the supply of power to the compensated circuit of induction through-heating
equipment, being mains frequency single phase or three phases power supply or
semiconductor frequency converter and having the following main specified characteristics:
or frequency band f f
• frequency f ….
2 21 22
• voltage U (RMS value)
• current I (RMS value)
• active power P
[SOURCE: IEC 62076:2006, 3.13， modified – The types of power source used have been
specified and supplemented, see Annex AA.]
3.109
compensated circuit of induction through-heating equipment
electric circuit comprising one or more inductors, a compensating capacitor bank and a load-
matching transformer (if applicable)
Note 1 to entry: See Annex AA.
3.110
mass of test billets
G
test
out of the through-heated billets, total mass of those qualified used for the determination of
specific energy consumption and productivity
3.111
dimensions of billet
maximum dimensions of the overall billets with any transport or protection means, which the
induction through-heating equipment is designed for and is marked on the rating plate,
expressed in diameter × length or width × thickness × length
3.112
billet temperature
θ
b
temperature of the billet at a given time of the through-heating cycle
3.113
starting temperature of billet
θ
bs
temperature of the billet at the beginning of the through-heating cycle

IEC 63078:2019 © IEC 2019 – 9 –
3.114
final temperature of billet
θ
bf
temperature of the billet attained at the end of the holding period of the through-heating cycle
3.115
rated temperature of billet
θ
br
temperature to be requested by through-heating technology for the billet of a given material,
which the induction through-heating equipment is designed for and which is marked on the
rating plate
3.116
temperature homogeneity of billet
Δθ
b
homogeneous degree of billet temperature when it is extracted after heating and holding,
which is expressed as the maximum and minimum deviations of the temperatures measured
at the temperature measuring points with the rated temperature of the billet (they may be
positive or negative), or expressed as the transverse (radial) temperature difference and the
longitudinal temperature difference of the billet for the long billets with a circular or
rectangular, etc. uniform cross section
Note 1 to entry: Requirements and measuring conditions for the determination of billet temperature homogeneity
are specified in Annex CC.
3.117
transverse temperature difference of billet
radial temperature difference of billet
Δθ
bt(r)
maximum and minimum temperature differences which may be positive or negative, between
periphery and centre on the cross section of a long billet with a uniform cross section when it
is extracted after its heating and holding
Note 1 to entry: Usually, the temperature at the centre of a billet cross section is lower.
Note 2 to entry: The radial temperature difference Δθ applies for a billet with a circular cross section.
br
3.118
longitudinal temperature difference of billet
Δθ
bl
difference between the maximum temperature and the minimum temperature along the
longitudinal direction of a long billet with a uniform cross section when it is extracted after its
heating and holding
Note 1 to entry: Usually, the temperature at two ends of a billet is lower.
3.119
inlet temperature of cooling water
θ
wi
temperature of the cooling water when entering the cooling water circuit of the heating
inductor
[SOURCE: IEC 62076:2006, 3.33， modified – The term and its symbol have been changed,
the words “coolant” and “inductor assembly” have been replaced by “cooling water” and
“heating inductor”.]
3.120
outlet temperature of cooling water

θ
wo
temperature of the cooling water when leaving the cooling water circuit of the heating inductor,
with the induction through-heating equipment operating at rated conditions

– 10 – IEC 63078:2019 © IEC 2019
[SOURCE: IEC 62076:2006, 3.34， modified – The term and its symbol have been changed,
the words “coolant”, “inductor assembly” and “furnace” have been replaced respectively by
“cooling water”, “heating inductor” and “induction through-heating equipment”.]
3.121
equipment duty at rated conditions
rated equipment duty
induction through-heating equipment operation with specified dimensions of lining and billet,
specified billet quantity, rated power and rated frequency range without exceeding the
maximum voltage and current defined by the supplier
3.122
thermal steady state
thermal state in which the whole energy input into the induction through-heating
equipment is used for the compensation of its thermal losses
Note 1 to entry: In thermal steady state, the temperatures of all constructional components of induction through-
heating equipment and all the outlet temperatures of the cooling water are relatively stable and do not rise.
[SOURCE: IEC 62076:2006, 3.36, modified – The “furnace” has been replaced by “induction
through-heating equipment” and the note added.]
3.123
hot state
thermal steady state of the induction through-heating equipment when the billet
is at its final temperature
[SOURCE: IEC 60683:2011, 3.13， modified – The definition suitable for induction through-
heating equipment has been given with the ambiguous term “thermal condition” replaced by
“thermal steady state” and “furnace” by “induction through-heating equipment”.]
3.124
cold state
thermal state in which the induction through-heating equipment is not energized
and the temperature of the whole equipment is at ambient temperature
[SOURCE: IEC 60683:2011, 3.4， modified – The definition suitable for induction through-
heating equipment has been given.]
3.125
holding power
P
h
active power supplied to the power circuit of induction through-heating
equipment, in order to maintain the specified billet at a specified temperature for its
temperature homogeneity
[SOURCE: IEC 60398:2015, 3.3.2， modified – The original definition including its two notes,
has been simplified according to induction through-heating equipment.]
3.126
electrical energy consumption of the equipment
electrical energy supplied to the power circuit of induction through-heating equipment during
the defined time period
Note 1 to entry: E .is the active electrical energy consumption.
ae
Note 2 to entry: E is the reactive electrical energy consumption.
re
IEC 63078:2019 © IEC 2019 – 11 –
[SOURCE: IEC 62076:2006, 3.42， modified – The words “energy consumption” and “furnace”
have been changed to “electrical energy consumption” and “induction through-heating
equipment”, and "during the defined time period" and the notes have been added.]
3.127
electrical energy consumption of the installation
active electrical energy consumption
E
ai
electrical energy supplied to the induction through-heating installation during the defined time
period, including the active electrical energy consumption of the equipment E and the active
ae
electrical energy consumption of electrical and mechanical auxiliaries of the equipment E
aa
3.128
specific electrical energy consumption of the equipment/installation
e /e
e i
ratio of the electrical energy consumption of the equipment/installation E /E for heating
ae ai
to rated temperature θ and then holding
specified billets from their starting temperature θ
bs br
them for temperature homogeneity, to the total mass of qualified billets of those through-
heated billets, during a complete cycle of the batch heating type installation or a longer
defined time period of the continuous heating type and stage heating type installations
Note 1 to entry: For a partial through-heating application, only the total mass of the through-heated parts of
qualified billets is considered.
[SOURCE: IEC 60398:2015, 3.2.3， modified – The words “energy consumption” and “energy”
have been changed to “electrical energy consumption”, the definition suitable for three types
of induction through-heating equipment/installation has been given with a note added.]
3.129
productivity
g
ratio of the total mass of qualified billets of those through-heated billets for
heating specified billets from their starting temperature θ to rated temperature θ and then
bs br
holding them for temperature homogeneity, to the time of a complete cycle of the batch
heating type installation or a longer defined time period of the continuous heating type and
stage heating type installations, during the complete cycle or the defined time period
Note 1 to entry: For partial through-heating application, only the total mass of the through-heated parts of
qualified billets is considered.
[SOURCE: IEC 60050-841:2004, 841-22-71, modified – The definition suitable for three types
of induction through-heating installation has been given with a note added.]
3.130
heating efficiency of the equipment/installation
η /η
e i
ratio of the usable enthalpy increase in the qualified billets of those through-heated billets to
the active electrical energy consumption of the equipment E or to the active electrical
ae
energy consumption of the installation E during a complete cycle of the batch heating type
ai
installation or a longer defined time period of the continuous heating type and stage heating
type installations
[SOURCE: IEC 60398:2015, 3.2.4， modified – The definition suitable for three types of
induction through-heating equipment/installation has been given.]
4 Basic provisions for testing and test conditions
This clause of IEC 60398:2015 is applicable except as follows.

– 12 – IEC 63078:2019 © IEC 2019
4.3 Boundaries of the energy using system for testing
Additional subclause:
4.3.101 Boundaries of induction through-heating installation for testing
The energy consumption of an induction through-heating installation shall also include:
a) energy consumption of the power circuit of the induction through-heating equipment for
heating and holding billets;
b) energy consumption of the control system of the installation.
The corresponding energy consumption supplied by some public service, for example
hydraulic and/or pneumatic pumping station(s) to the installation, may be estimated according
to the practical use or ignored when it is very small compared with the whole energy
consumption of the installation.
4.4 General requirements for testing
This subclause of IEC 60398:2015 is applicable except for the following replacement and
additions.
Replacement (of the first paragraph of this subclause of IEC 60398:2015):
The relevant safety requirements in IEC 60519-1:—, IEC 60519-3:2005 and the
manufacturer’s instructions shall be observed and necessary protective measures taken
during all tests, to ensure safety.
Additions:
The tests of an induction through-heating installation are divided into cold state tests and hot
state tests. Unless otherwise specified, the hot state tests shall be undertaken after the cold
state tests are qualified.
The cold state tests shall be undertaken after manufacture or repair as well as during
installation and regulation in the cold state. Installation and test preparation shall be carried
out according to the manufacturer’s instructions. Before the test, the electrical connections,
switches, control system and some dimensions, etc. of the installation shall be inspected.
The hot state tests shall be undertaken with a new lining of specified dimensions and
materials as agreed between the manufacturer and the user. The requirements for test billets
shall be in accordance with 6.7.101. The technological process for heating and holding shall
be agreed between the manufacturer and the user. The technological process also includes
the loading, temperature measurement and unloading of billet. Where a test is to be
performed in the hot state (see 3.123), the induction through-heating equipment shall have
been in operation for at least 8 h (depending on the dimensions of billet or agreed between
the manufacturer and the user) prior to the test. In the case where it starts with a new lining, it
shall have been in operation for at least 24 h prior to the test.
The electrical data at the input of the supply line to be established by the tests of items b), c)
and e) of 8.3 are related to the rated voltage U and the rated frequency f . Admissible
n n
deviations from the rated voltage and frequency shall be agreed between the manufacturer
and the user. If during the test these deviations are exceeded, this shall be taken into account
in the evaluation.
In the case where a mains transformer is used solely for the induction through-heating
equipment, the electrical values at the input of the supply line may be determined from the
corresponding values on the secondary side of the transformer taking into account its
characteristic.
IEC 63078:2019 © IEC 2019 – 13 –
All measurements are to be taken using appropriate devices and following accurately the
instructions for their use. The accuracy tolerances of all measuring instrument or devices (for
values of electrical data, temperature and mass) shall be established and agreed between the
manufacturer and the user.
In addition, all equipment composing the induction through-heating installation shall comply
with their relevant specifications.
Attention should be drawn to the different parameters to be considered as regards the rated
values of an induction through-heating equipment and to the tests intended for their
verification; irrespective of the size of the equipment, its performance depends on:
– the heating type of the equipment;
– the design of the equipment and its heating inductor themselves;
– the material, shape and dimensions of the billet;
– the type and automation degree of the handling mechanisms of the billet;
– the type and frequency of the power supply unit used to feed the equipment;
– the type of control and regulating system of the power supply unit for the equipment;
– the ability of the power supply unit of the equipment to react to rapid variations of reactive
power.
4.6 Environmental conditions during tests
Addition:
The inlet and outlet temperatures of cooling water of cooling circuits, especially for heating
inductors, shall observe the manufacturer’s instructions. Excessive or less cooling will
influence the measurement of energy efficiency.
5 Comparing equipment or installations
This clause of IEC 60398:2015 is applicable.
6 Measurements and workloads
This clause of IEC 60398:2015 is applicable except as follows.
6.3 Frequency measurement
Addition:
The accuracy of frequency measurement shall be of class 1.5 or better for mains frequency
and medium frequency.
6.4 Measurement of electric data
6.4.1 Supply voltage
Addition:
NOTE Information on the influences of actual supply voltage or its variation on the performance of the installation
can be found in 8.10 of IEC 60398:2015.

– 14 – IEC 63078:2019 © IEC 2019
6.4.2 Voltage, current, electrical power and resistance
Addition:
The accuracy of equipment for voltage, current, power and electric energy measurements in
the medium frequency shall be of class 2.5 or better.
When the waveforms of voltage and current show distortion, for example in the input and
output terminals of the semiconductor frequency converter, special care should be taken and
the measuring equipment used shall be able to show true RMS independent from the
waveform.
6.4.3 Measurement positions
Addition:
For measurement positions of all electrical parameters of the power circuit of the induction
through-heating equipment, see Figures AA.1 to AA.3; they are at the output terminals of the
supply disconnecting device for the electrical energy consumption measurement of the power
circuit, and at the output terminals of the power distribution cabinet in shop for other electrical
and mechanical auxiliaries (see 4.3 of IEC 60398:2015 and b) of 4.3.101).
6.7 Workload
Additional subclause:
6.7.101 Test billet of induction through-heating installation
Actual billets shall be used as test billets and their material, shape and dimensions shall be in
accordance with the design specifications of the installation. Test billets are provided by the
user and their surfaces shall be clean and dry as well as have no scale and obvious burr,
especially for the determination of temperature homogeneity of the billet in order to accurately
measure the surface temperature.
7 Numerical modelling
This clause of IEC 60398:2015 is applicable with the following addition.
NOTE 101 For the numerical modelling method determining temperature homogeneity of billet, see Annex CC.
8 List of tests
8.1 General requirements
The test items related to safety and mechanical aspects also are important parts of a
complete set of tests of the installation. Main safety test items include the measurements of
insulation resistance, electric or magnetic fields and touch current as well as the protection
test by automatic disconnection of supply, voltage test, dielectric test and accessibility test of
live parts, etc. and the test methods shall follow 18.6.1 to 18.6.3 and 18.7.1 to 18.7.4 of
IEC 60519-1:—. Mechanical test items include various tests of billet handling mechanisms,
the test methods are intended to follow relevant ISO standards.
The tests of the induction through-heating installation may be selected from the tests listed in
IEC 60398:2015, with necessary supplements made, according to the installation’s features
and user’s needs. For the test items listed below, this document provides test methods which
modify or supplement the related test methods in IEC 60398:2015 and IEC 60519-1:—,
according to the installation’s features.

IEC 63078:2019 © IEC 2019 – 15 –
8.2 Cold state tests
The following cold state tests are related to safety (see Annex DD):
a) electrical withstand test of heating inductors (see Clause DD.1);
b) tightness test of cooling water circuits (see Clause DD.2);
c) flow test of cooling water circuits (see Clause DD.3).
8.3 Hot state tests
The following hot state tests are optional and may be selected as required for the
characterization and evaluation of an induction through-heating installation:
a) measurement of temperature rise of cooling water (see 9.101);
b) determination of power and power factor of power circuit of induction through-heating
equipment (see 9.102);
c) determination of holding power (see 9.103);
d) determination of temperature homogeneity of billet (see 9.104);
e) determination of specific electrical energy consumption and productivity (see 9.105);
f) determination of heating efficiency of the equipment/installation (see 9.106);
g) measurement of temperatures of structural components subject to heat (see 9.107).
9 Technical tests and efficiency of the installation
NOTE This clause corresponds to Clauses 8 and 9 of IEC 60398:2015.
The relevant parts of Clauses 8 and 9 of IEC 60398:2015 are applicable except as follows.
Additional subclauses:
9.101 Measurement of temperature rise of cooling water
This test shall be carried out in the hot state (see 3.123 and 4.4) of the induction through-
heating equipment operating at its rated equipment duty (see 3.121), with the flow rate
specified by the manufacturer, at the end of the test given in 9.6. The temperature of the
cooling water shall be measured by thermometers or monitored by sensors at the inlet and
outlet of the cooling water circuits of the equipment. The difference between the outlet and
inlet temperatures is the value of temperature rise of the cooling water. During the test, the
outlet temperature and the temperature rise shall be within the manufacturer's specifications.
It is recommended that several readings be taken, for example, every 5 min towards the end
of the test period given in 9.6, to ascertain that the equipment has attained a stable hot state
condition.
9.102 Determination of input power P and power factor λ of power circuit of induction
through-heating equipment
The active power P is to be measured and the apparent power S can be determined by the
measurements of the current I and voltage U at rated equipment duty (see 3.121) and in the
hot state (see 3.123 and 4.4) of the induction through-heating equipment, see Figure AA.1.
The power factor λ can be calculated as the ratio of the active power and the apparent power.

– 16 – IEC 63078:2019 © IEC 2019
A low content of voltage and/or current harmonics does not significantly affect the test result;
in these conditions, the power factor λ becomes practically equal to the cos φ measured by
means of a cos φ-meter. In the case of a three-phase supply, it should be ensured that, during
these measurements, currents in the three phases show no significant unbalance. It should be
considered as a guideline that this requirement is met when the deviation of the current
values from their mean value does not exceed ±10 %. Where the out-of-balance of the three-
phase line currents exceeds ±10 %, an appropriate and more accurate method should be
employed.
Active and reactive power remaining relatively constant during this test, active power may
also be determined by the active energy (measured by an energy-meter) consumed during a
given time period divided by the time of the time period. Similarly, power factor λ may be
determined by measuring the active and reactive energy consumed in the same time period
by means of adequate energy-meters.
9.103 Determination of holding power P
h
The test shall be carried out after the induction through-heating equipment containing the
specified billet has been in normal operation for a sufficient time to ensure that it is in the hot
state (see 3.12
...