EN IEC 60676:2024

SLOVENSKI STANDARD
01-junij-2024
Oprema za industrijsko električno ogrevanje - Preskusne metode za peči z
odkritim oblokom (IEC 60676:2024)
Industrial electroheating equipment - Test methods for direct arc furnaces (IEC
60676:2024)
Industrielle Elektrowärmeanlagen - Prüfverfahren für Lichtbogen-Schmelzöfen (IEC
60676:2024)
Chauffage électrique industriel - Méthodes d'essai des fours à arc direct (IEC
60676:2024)
Ta slovenski standard je istoveten z: EN IEC 60676:2024
ICS:
25.180.10 Električne peči Electric furnaces
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EUROPEAN STANDARD EN IEC 60676

NORME EUROPÉENNE
EUROPÄISCHE NORM April 2024
ICS 25.180.10 Supersedes EN 60676:2012
English Version
Industrial electroheating equipment - Test methods for direct arc
furnaces
(IEC 60676:2024)
Chauffage électrique industriel - Méthodes d'essai des fours Industrielle Elektrowärmeanlagen - Prüfverfahren für
à arc direct Lichtbogen-Schmelzöfen
(IEC 60676:2024) (IEC 60676:2024)
This European Standard was approved by CENELEC on 2024-04-03. 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,
Türkiye 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
© 2024 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN IEC 60676:2024 E
European foreword
The text of document 27/1181/FDIS, future edition 4 of IEC 60676, 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 60676:2024.
The following dates are fixed:
• latest date by which the document has to be implemented at national (dop) 2025-01-03
level by publication of an identical national standard or by endorsement
• latest date by which the national standards conflicting with the (dow) 2027-04-03
document have to be withdrawn
This document supersedes EN 60676:2012 and all of its amendments and corrigenda (if any).
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.
Any feedback and questions on this document should be directed to the users’ national committee. A
complete listing of these bodies can be found on the CENELEC website.
Endorsement notice
The text of the International Standard IEC 60676:2024 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 standard indicated:
The Bibliography of EN 60398:2015 is applicable with the following addition:
IEC 60076 (series) NOTE Approved as EN 60076 (series)
IEC 60146-1-1 NOTE Approved as EN 60146-1-1
IEC 60683:2011 NOTE Approved as EN 60683:2012 (not modified)
IEC 61869 (series) NOTE Approved as EN IEC 61869 (series)
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.cencenelec.eu.
Publication Year Title EN/HD Year
IEC 60398 2015 Installations for electroheating and EN 60398 2015
electromagnetic processing - General
performance test methods
IEC 60519-1 - Safety in installations for electroheating EN IEC 60519-1 -
and electromagnetic processing - Part 1:
General requirements
IEC 60519-4 2021 Safety in installations for electroheating EN IEC 60519-4 2022
and electromagnetic processing - Part 4:
Particular requirements for arc furnace
installations
ISO 13578 - Industrial furnaces, and associated - -
processing equipment - Safety
requirements for machinery and equipment
for production of steel by electric arc
furnaces
IEC 60676 ®
Edition 4.0 2024-02
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Industrial electroheating equipment – Test methods for direct arc furnaces

Chauffage électrique industriel – Méthodes d'essai des fours à arc direct

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 25.180.10  ISBN 978-2-8322-8367-7

– 2 – IEC 60676:2024 © IEC 2024
CONTENTS
FOREWORD . 4
INTRODUCTION . 6
1 Scope . 7
2 Normative references . 7
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions . 8
3.2 Abbreviated terms . 12
4 Basic provisions for testing and test conditions . 13
4.1 Aim of testing . 13
4.2 Communication of test results . 13
4.3 Boundaries of the energy using system for testing . 13
4.3.1 General considerations . 13
4.3.2 Batch type installations . 13
4.3.3 Continuous type installations . 14
4.4 General requirements for testing . 14
4.5 Operating conditions during tests . 14
4.6 Environmental conditions during tests . 14
4.7 Supply voltage . 14
5 Comparing equipment or installations . 15
6 Measurements and charged material . 15
6.1 General . 15
6.2 Time resolution . 15
6.3 Frequency measurement . 15
6.4 Measurement of electrical data . 15
6.4.1 Supply voltage and current . 15
6.4.2 Voltage, current, electrical power and resistance . 15
6.4.3 Measurement positions . 16
6.5 Temperature measurement . 16
6.5.101 Dipping probes for liquid steel or slag . 16
6.6 Measurement of pressure, humidity or composition of fluids . 16
6.7 Charged material . 16
7 Numerical modelling . 17
8 Technical tests . 18
8.101 General . 18
8.102 Electrical insulation . 18
8.103 Cold function test . 18
8.104 Hot commissioning . 18
8.104.1 General . 18
8.104.2 Energy consumption during holding operation . 18
8.104.3 Energy consumption during normal operation . 19
8.104.4 Rated arc furnace capacity . 19
8.105 Preparation for performance test . 19
8.105.1 Performance dependence on supply voltage . 20
8.105.2 Processing range of intended operation . 20
8.105.3 Short circuit test . 20
8.105.4 Electrode consumption . 20

IEC 60676:2024 © IEC 2024 – 3 –
8.105.5 Tap-to-tap time . 20
8.105.6 Power on time . 20
8.105.7 Arcing time . 20
8.105.8 Process time . 20
8.105.9 Apparent power . 20
8.105.10 Active power . 20
8.105.11 Reactive power . 21
8.105.12 Power factor . 21
9 Efficiency of the installation . 21
9.1 General . 21
9.2 Specific energy consumption . 21
9.3 Heating efficiency of arc furnace installation . 21
9.4 Supply power usage efficiency . 22
9.5 Energy transfer efficiency . 22
Annex A (informative) Energy efficiency assessment . 23
Annex B (informative) Visual display of energy efficiency related information . 24
B.101 General . 24
B.102 Sankey diagram of power balance – to be adapted to EAF route . 24
B.103 Time resolved power usage diagram . 25
Annex C (informative) Estimating energy use . 28
C.1 General . 28
C.2 Minimum energy consumption . 28
C.3 Holding power . 29
C.4 Transfer losses and transfer efficiency . 29
C.5 Examples . 29
Annex D (informative) Energy recoverability . 30
Annex AA (informative) Short circuit test procedures (dip test) . 31
AA.1 General . 31
AA.1.1 EAF AC . 31
AA.1.2 EAF DC . 31
AA.2 High current system: resistance and reactance of EAF AC . 31
AA.3 Impedances determined by short circuit test . 31
AA.4 Test procedures for EAF AC . 32
AA.5 Reactance asymmetry factor . 36
AA.6 Uncertainties of the operational short circuit measurements . 37
Bibliography . 38

Figure B.101 – Sankey diagram of a 130 MVA EAF DC (see Bibliography, Kühn) . 24
Figure B.102 – Example of a time resolved power usage diagram of EAF scrap melting . 26
Figure AA.1 – Typical single line diagram for measuring electrical data of the high
current system to determine the resistance and reactance values . 33

– 4 – IEC 60676:2024 © IEC 2024
INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
INDUSTRIAL ELECTROHEATING EQUIPMENT –
TEST METHODS FOR DIRECT ARC FURNACES

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) IEC draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). IEC takes no position concerning the evidence, validity or applicability of any claimed patent rights in
respect thereof. As of the date of publication of this document, IEC had not received notice of (a) patent(s), which
may be required to implement this document. However, implementers are cautioned that this may not represent
the latest information, which may be obtained from the patent database available at https://patents.iec.ch. IEC
shall not be held responsible for identifying any or all such patent rights.
IEC 60676 has been prepared by IEC technical committee 27: Industrial electroheating and
electromagnetic processing. It is an International Standard.
This fourth edition cancels and replaces the third edition published in 2011. This edition
constitutes a technical revision.
This edition includes the following significant technical changes with respect to the previous
edition:
a) The structure has been redrafted according to IEC 60398:2015.
b) The scope has been redrafted.
c) The terms/definitions, normative references and bibliography have been updated and
completed.
d) The test methods and content from IEC 60398:2015 have been confirmed, replaced, or
complemented with regards to direct arc furnaces (EAF, LF).

IEC 60676:2024 © IEC 2024 – 5 –
e) The annexes from IEC 60398:2015 have been confirmed, replaced, or complemented with
regards to direct arc furnaces (EAF, LF).
The text of this International Standard is based on the following documents:
Draft Report on voting
27/1181/FDIS 27/1184/RVD
Full information on the voting for its approval can be found in the report on voting indicated in
the above table.
The language used for the development of this International Standard is English.
This standard is to be read in conjunction with IEC 60398:2015. It supplements or replaces the
corresponding clauses of IEC 60398:2015. Where the text indicates a "modification" of,
"addition" to or a "replacement" of the relevant provision of IEC 60398:2015, these changes are
made to the relevant text of IEC 60398:2015. Where no change is necessary, the words "This
clause of IEC 60398:2015 is applicable" are used. When a particular subclause of
IEC 60398:2015 is not mentioned in this standard, that subclause applies as far as it is
reasonable. When a particular subclause of IEC 60398:2015 is not applicable, the word "Void"
is used.
In this standard, the following print types are used:
• terms defined in Clause 3: bold type.
This document was drafted in accordance with ISO/IEC Directives, Part 2, and developed in
accordance with ISO/IEC Directives, Part 1 and ISO/IEC Directives, IEC Supplement, available
at www.iec.ch/members_experts/refdocs. The main document types developed by IEC are
described in greater detail at www.iec.ch/publications.
The committee has decided that the contents of this document will remain unchanged until the
stability date indicated on the IEC website under webstore.iec.ch in the data related to the
specific document. At this date, the document will be
• reconfirmed,
• withdrawn, or
• revised.
IMPORTANT – The "colour inside" logo on the cover page of this document indicates
that it contains colours which are considered to be useful for the correct understanding
of its contents. Users should therefore print this document using a colour printer.

– 6 – IEC 60676:2024 © IEC 2024
INTRODUCTION
Direct electrical arc furnaces are very important applications for steel scrap melting, melting of
direct reduced iron (DRI), hot bricked iron (HBI) or hot metal. While ladle furnaces are mainly
used for providing the required quality and final adjustment of temperature of molten steel
before sending to casting machine or to vacuum treatment stations.
The manufacturer of the installation or equipment usually fulfils the following requirements,
which come from different sources and are quite often in this order of priorities:
a) to enable the intended process and make the installation work properly;
b) to be cost effective during design and manufacturing;
c) to ensure that the equipment is safe to use in the sense of providing freedom from
unacceptable risk of physical injury or damage to the health of the operator (safety in the
narrower sense of ISO 12100:2010);
d) to ensure that the equipment is safe to use in the sense of providing freedom from
unacceptable risk or physical injury or damage to the health of people, or damage to property
or the environment (adding other safety aims to item c), and in the much broader definition
of safety according to ISO/IEC Guide 51);
e) to prove that the equipment is cost effective to operate and uses sufficiently small amounts
of energy, material and other resources.
It is usually part of the proprietary knowledge of the manufacturer or user of the equipment, to
make it cost effective or enable intended processes with a benefit. IEC 60519-1 and
IEC 60519-4 assist with achieving safety in the ISO 12100:2010 sense. The focus of this
document is on basic requirements for measuring instrumentation and test methods concerned
with energy and resource efficiency, performance of the intended process and assessing cost
of ownership for installations and equipment.
This document presumes that the installation or equipment is operated and maintained only by
personnel consisting of skilled or instructed persons.

IEC 60676:2024 © IEC 2024 – 7 –
INDUSTRIAL ELECTROHEATING EQUIPMENT –
TEST METHODS FOR DIRECT ARC FURNACES

1 Scope
This clause of IEC 60398:2015 is replaced by the following.
Replacement:
This document specifies the basic test procedures, conditions and methods for establishing the
main performance parameters and the main operational characteristics of furnaces for direct
arc heating, forming arcs between the electrode and metal, such as electric arc furnaces using
alternating current (EAF AC) or direct current (EAF DC), and ladle furnaces (LF), with rated
power level above 500 kVA .
Measurements and tests that are solely used for the verification of safety requirements of
equipment for direct electrical arc furnaces are outside the scope of this document and are
covered by IEC 60519-1, IEC 60519-4 and ISO 13578.
This document is applicable for the commissioning, verification of design improvements or for
energy related tasks with respect to energy use or energy efficiency, establishing of an energy
baseline, and labelling. Some concepts from this document can directly be used as key
performance indicators.
Detailed tests for specific types of electric arc furnace equipment and installations are beyond
the scope of this document. This document is intended as general reference for all future test
standards applicable to particular electric arc furnace equipment or installations.
This document includes the concept and material presented in IEC 60398 on energy efficiency
dealing with the electrical and processing parts of the equipment, as well as the overall
performance.
Test methods for some special equipment, e.g., semiconductor converters, are covered by
IEC 60146-1-1 and furnace transformers are covered by IEC 60076 series.
Test methods for submerged arc furnaces (SAF) are covered by IEC 60683.
2 Normative references
This clause of IEC 60398:2015 is replaced by the following.
Replacement:
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies.
For undated references, the latest edition of the referenced document (including any
amendments) applies.
IEC 60398:20215, Installations for electroheating and electromagnetic processing – General
performance test methods
– 8 – IEC 60676:2024 © IEC 2024
IEC 60519-1, Safety in installations for electroheating and electromagnetic processing – Part 1:
General requirements
IEC 60519-4:2021, Safety in installations for electroheating and electromagnetic processing –
Part 4: Particular requirements for arc furnace installations
ISO 13578, Industrial furnaces, and associated processing equipment – Safety requirements
for machinery and equipment for production of steel by electric arc furnaces
3 Terms, definitions and abbreviated terms
3.1 Terms and definitions
For the purposes of this document, the terms and definitions given in IEC 60398:2015 and the
following apply.
ISO and IEC maintain terminology databases for use in standardization at the following
addresses:
• ISO Online browsing platform: available at https://www.iso.org/obp
• IEC Electropedia: available at https://www.electropedia.org
NOTE The terms and definitions refer to EAF and/or LF where applicable.
3.1.101
active power
P
under periodic conditions, mean value, taken over one period T of the instantaneous power p
T
P= p dt
∫
T
Note 1 to entry: Under sinusoidal conditions, the active power is the real part of the complex power S,
thus P = Re (S).
Note 2 to entry: The coherent SI unit for active power is Watt, W.
[SOURCE: IEC 60050-131:2002, 131-11-42]
3.1.102
apparent power
S
power rating of the furnace transformer, energizing the EAF or LF (in MVA)
S= 3 UI (for three-phase system)

where
U is the voltage, RMS, sinusoidal value [in kV]
I is the current, RMS sinusoidal value [in kA]
[SOURCE: IEC 60050-131:2002, 131-11-41, modified – more precise]

IEC 60676:2024 © IEC 2024 – 9 –
3.1.103
arc furnace
furnace with a vessel, in which metal or other charged conducting material is heated mainly by
electric arc or joule effect using alternating current (AC) or direct current (DC)
[SOURCE: IEC 60050-841:2004, 841-26-05, modified – more precise]
3.1.104
arcing time
actual current flow time during power-on time
Note 1 to entry: Arcing time represents a high percentage of power on time.
Note 2 to entry: It is expressed in minutes (min).
3.1.105
asymmetry factor
K
difference between maximum and minimum impedance of any phase, divided by the mean
impedance of all three phases (in %)
3.1.106
arc furnace transformer
transformer changing high voltage electrical power supply to a lower voltage and higher
current for an arc furnace process
[SOURCE: IEC 60050-841:2004, 841-26-55, modified – more precise]
3.1.107
capacity
quantity of liquid material, which can be produced in the EAF during one heat (in t)
Note 1 to entry: Whether metric or short tons according to pre-requisites.
3.1.108
cold state
thermal state of EAF installation when the temperature of all parts equals the ambient
temperature
3.1.109
clean bus
high voltage bus system which supplies the auxiliary equipment (e.g., motor control center,
control system) where the network distortions are considered to be lower than in the dirty bus
system
3.1.110
DC reactor
inductor smoothing electrical high frequency fluctuations, due to changes
in arc conditions
Note 1 to entry: In case multiple rectifiers are coupled in the system, inductors can decrease the fluctuations as
well.
3.1.111
dirty bus
high voltage bus system which supplies the furnace transformer and contains the network
distortions from the process (e.g., flicker, harmonics)
Note 1 to entry: Distortion values on the dirty bus can exceed the limits of power quality of the grid.

– 10 – IEC 60676:2024 © IEC 2024
3.1.112
disconnector
grounding switch
motor operated non load switch providing visible safety distance and connection to ground
installed between the furnace switchgear and the furnace transformer
3.1.113
electric arc furnace using alternating current
EAF AC
furnace, in which electric arcs between the electrodes and conducting material are formed,
using alternating current
[SOURCE: IEC 60050-841:2004, 841-26-07 modified – more precise]
3.1.114
electric arc furnace using direct current
EAF DC
furnace, in which the direct current is conducted via bottom electrode(s) (anode) to the
material to be processed, forming arcs between the material and the electrode(s) from top
(cathode)
[SOURCE: IEC 60050-841:2004, 841-26-06, modified – more precise]
3.1.115
EAF electrode
LF electrode
part produced from high density graphite to transfer the electrical energy forming arcs between
tip and charge material
[SOURCE: IEC 60050-841:2004, 841-26-38, modified – more precise]
3.1.116
furnace shell
vessel of arc furnace made from metal (currently: steel) and covered by a roof
[SOURCE: IEC 60050-841:2004, 841-26-20, modified – more precise]
3.1.117
furnace switchgear
high-voltage switchgear connecting the furnace transformer to the electrical supply providing
switching on/off under load
3.1.118
heat melt
liquid metal which is tapped after one process batch from an EAF into a ladle
Note 1 to entry: One heat produced during one process cycle.
3.1.119
high current system
assembly of conductors to carry the high current between furnace transformer secondary
bushings and electrode(s)
Note 1 to entry: It consists of the bus bar system, cables and either a current tube system or current conducting
electrode arm to the electrodes.
[SOURCE: IEC 60050-841:2004, 841-26-54, modified – more precise]

IEC 60676:2024 © IEC 2024 – 11 –
3.1.120
hot state
thermal state of an EAF in which the lining temperature is above 600 °C and a steady-
state temperature of the components is reached
3.1.121
operational short circuit
short circuit due to direct contact of at least two electrodes in an EAF AC with charge/liquid
material
Note 1 to entry: In EAF DC, short circuit is reached if the electrode from the top is in contact with the charge/liquid
material.
[SOURCE: IEC 60050-841:2004, 841-26-70, modified – more precise]
3.1.122
phase rotation
phase sequence of the electromagnetic field
3.1.123
power factor
λ
ratio of the active power to the apparent power measured on the primary side of the furnace
transformer
P
λ=
S
where
P is the active power [in MW]
S is the apparent power [in MVA]
Note 1 to entry: cos φ contains only fundamental grid frequency, 50 / 60 Hz.
Note 2 to entry: λ contains the fundamental and harmonic frequencies.
3.1.124
power on time
time p-on
time from first arcing till switching off the furnace circuit breaker per heat
Note 1 to entry: It is expressed in minutes (min).
3.1.125
process time
actual time during of energy input (electrical, gas, oxygen, etc.)
Note 1 to entry: It is expressed in minutes (min).
3.1.126
production rate
total quantity of metal (in t) tapped, divided by the tap-to-tap time
Note 1 to entry: It is expressed in t/h.

– 12 – IEC 60676:2024 © IEC 2024
3.1.127
reactive power
Q
total reactive electrical power (in MVAr) used in the system, measured on the primary side of
the furnace transformer
Q= SP– (for three-phase system)
[SOURCE: IEC 60050-131:2002, 131-11-44, modified – more precise]
3.1.128
rectifier
device by means of which alternating current is transferred into direct current
3.1.129
series reactor
reactor connected in series to the furnace transformer to minimise impacts on the electrical
supply created by the arcs and ensure arc stability during the process
3.1.130
specific electrical energy consumption
quotient of electrical energy consumed (in kWh) during melting and superheating of
the metal (in t) tapped at a specified temperature
Note 1 to entry: It is expressed in kWh/t.
[SOURCE: IEC 60050-841:2004, 841-22-72, modified – more precise]
3.1.131
tap to tap time
t
ttt
time between end of tapping of previous heat and end of tapping of actual heat
Note 1 to entry: It is expressed in minutes (min).
3.2 Abbreviated terms
AC Alternating current
CT Current transformer
DC Direct current
DRI Direct reduced iron
EAF Electric arc furnace
HBI Hot briquetted iron
LF Ladle furnace
LPG Liquid petrol gas
PT Potential transformer
SAF Submerged arc furnace
SVC Static VAr compensation
IEC 60676:2024 © IEC 2024 – 13 –
4 Basic provisions for testing and test conditions
4.1 Aim of testing
This subclause of IEC 60398:2015 is applicable.
4.2 Communication of test results
This subclause of IEC 60398:2015 is applicable with the following additions.
Addition:
The type of measurement equipment as well as the layout and arrangement of the measurement
points shall be mentioned in the test report.
4.3 Boundaries of the energy using system for testing
4.3.1 General considerations
This subclause of IEC 60398:2015 is applicable with the following additions.
Addition:
e) Energy used for gas cleaning systems shall be included in the calculation of used and lost
energy.
4.3.2 Batch type installations
This subclause of IEC 60398:2015 is not applicable and replaced by the following.
Replacement:
EAF installations typically operate in batch mode. The typical process can be described as
follows:
a) Charging of scrap, etc., in one batch / basket at the beginning of the heat.
b) Melt down and charging of next batch / basket incl. scrap, direct reduced iron (DRI), hot
briquetted iron (HBI) or hot metal steel. DRI or HBI may be charged continuously until the
full charging weight will be reached.
c) If only scrap is used as a raw material several more batches / baskets are necessary to
reach the final charging weight.
d) Overheating and start of deslagging: Heating up the molten material until tapping
temperature and start of deslagging.
e) Refining: Alloys can be charged to reach desired qualities. In some applications the refining
will be done in Ladle Furnace (LF).
f) Tapping of molten material into a ladle.
g) Tapping of residual slag into the slag pit / slag pot.
In some applications burners may be used after charging the batches / baskets. Foamy slag
(addition of lime, carbon and oxygen) is used during overheating and refining to protect the
lining and to increase electrical power input.

– 14 – IEC 60676:2024 © IEC 2024
4.3.3 Continuous type installations
This subclause of IEC 60398:2015 is not applicable and replaced by the following.
Replacement:
EAF continuous or semi-continuous process are not common.
4.4 General requirements for testing
This subclause of IEC 60398:2015 is applicable with the following replacement:
Replacement:
The relevant safety requirements of IEC 60519-4 and the manufacturer’s instructions shall be
observed during all tests, to ensure safety.
The furnace transformer/series reactor design shall offer at least one combination to enable
the dip test (see Annex AA).
The characteristics and parameters defined in Clause 8 shall be tested in the hot state of EAF
or LF installation:
a) during commissioning,
b) when the installation is ready for normal operation,
c) at regular intervals as specified by the manufacturer,
d) following maintenance or
e) after modifications.
The operator responsible for performing the measurements or tests shall be sufficiently trained
to make accurate tests and have enough time and resources at hand to perform measurements
and tests as intended and indicated in this document.
4.5 Operating conditions during tests
This subclause of IEC 60398:2015 is applicable with the following addition.
Addition:
The pre-conditions given by the manufacturer shall be fulfilled.
4.6 Environmental conditions during tests
This subclause of IEC 60398:2015 is applicable.
4.7 Supply voltage
This subclause of IEC 60398:2015 is applicable with the following addition.
Addition:
Voltage fluctuations and minimum fault level of incoming power supply line shall be agreed
between the supplier and user.

IEC 60676:2024 © IEC 2024 – 15 –
Tests shall be performed independently of the status of the compensation equipment (e.g. SVC,
Statcom, filter). Use or non-use of the compensation equipment shall be reported in the test
report.
NOTE Testing of EAF with use of compensation equipment and without use of compensation equipment will provide
information of the grid (short circuit power/fault level).
5 Comparing equipment or installations
Void.
6 Measurements and charged material
6.1 General
This clause of IEC 60398:2015 is applicable with the following addition.
Addition:
Type, number and quality of measurements and charged material need to be pre-defined by the
end user and the manufacturer in advance.
All measurement points shall be agreed upon between the supplier and user.
6.2 Time resolution
This subclause of IEC 60398:2015 is applicable.
6.3 Frequency measurement
Void.
6.4 Measurement of electrical data
6.4.1 Supply voltage and current
This subclause of IEC 60398:2015 is applicable with the modified headline.
6.4.2 Voltage, current, electrical power and resistance
This subclause of IEC 60398:2015 is applicable with the following replacement:
Replacement:
Voltage and current transformers shall be divided in 2 groups: Measurement and protection.
Measurement transformers are highly accurate but have a very limited overload capability
(typical 10 % to 20 %). Protection transformers usually have an accuracy of 10 %, but can be
overloaded highly (typically 10 times).
NOTE 1 For requirements of measurement transformers, see IEC 61869 series and IEC 60044 series.
The accuracy of equipment for voltage, current, power and energy measurements in the mains
frequency and lower range shall be of class 1,0 or better not only for high power factor
values >= 0,7 but also for power factor below 0,3 unless otherwise specified.
The electronic unit calculating the RMS value shall not significantly decrease the accuracy of
the fed voltage and current signals.

– 16 – IEC 60676:2024 © IEC 2024
Equipment for active power measurement shall use a four-point probe, if applicable; the used
probe type shall be part of the test report.
NOTE 2 Refer to Figure AA.1.
6.4.3 Measurement positions
This subclause of IEC 60398:2015 is applicable with the following addition:
Addition:
Location of voltage measurement shall be the feeding point of the primary voltage prior to the
series reactor / furnace transformer location (see Figure AA.1), if not otherwise agreed
between manufacturer and end user.
Any cable connection between substation and furnace switchgear shall not be included in the
measurement.
6.5 Temperature measurement
This subclause of IEC 60398:2015 is applicable with the following addition:
Addition:
6.5.101 Dipping probes for liquid steel or slag
The temperature of slag and hot metal is measured discontinuously depending on the progress
of the heat.
Latest developments show the use of glass fibre or other techniques for temperature
measurement in arc furnaces.
The relative measurement error for all temperature measurements in compliance with this
document shall be included in the test report.
6.6 Measurement of pressure, humidity or composition of fluids
This subclause of IEC 60398:2015 is applicable.
6.7 Charged material
This subclause of IEC 60398:2015 is not applicable and is replaced as follows:
Replacement:
The EAF will be cha
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