EN 60779:2005

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Industrial electroheat equipment - Test methods for electroslag remelting furnacesEquipements électrothermiques industriels - Méthodes d'essai des fours de refusion sous laitier électroconducteurIndustrielle Elektrowärmeanlagen - Prüfverfahren für Elektroschlacke-UmschmelzöfenTa slovenski standard je istoveten z:EN 60779:2005SIST EN 60779:2007en25.180.10ICS:SIST HD 470 S1:20031DGRPHãþDSLOVENSKI
STANDARDSIST EN 60779:200701-januar-2007

EUROPEAN STANDARD
EN 60779 NORME EUROPÉENNE EUROPÄISCHE NORM
November 2005 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
© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60779:2005 E
ICS 25.180.10 Supersedes HD 470 S1:1987
English version
Industrial electroheat equipment –
Test methods for electroslag remelting furnaces (IEC 60779:2005)
Equipements électrothermiques industriels –
Méthodes d'essai des fours de refusion sous laitier électroconducteur (CEI 60779:2005)
Industrielle Elektrowärmeanlagen - Prüfverfahren für Elektroschlacke-Umschmelzöfen (IEC 60779:2005)
This European Standard was approved by CENELEC on 2005-11-01. 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, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

The significant technical changes with respect to HD 470 S1:1987 are the additional technical tests described in 5.1, 5.2, 5.3, 5.9, 5.10, 5.11, 5.13, 5.14 and 5.15.
The following dates were fixed: – latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement
(dop)
2006-08-01 – latest date by which the national standards conflicting
with the EN have to be withdrawn
(dow)
2008-11-01 Annex ZA has been added by CENELEC. __________ Endorsement notice The text of the International Standard IEC 60779:2005 was approved by CENELEC as a European Standard without any modification. __________

- 3 - EN 60779:2005
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 Where 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 60398 1999 Industrial electroheating installations - General test methods
EN 60398 1999 IEC 60676 2002 Industrial electroheating equipment - Test methods for direct arc furnaces
EN 60676 2002
NORME INTERNATIONALECEIIEC INTERNATIONAL STANDARD 60779Deuxième éditionSecond edition2005-08 Equipements électrothermiques industriels – Méthodes d'essai des fours de refusion sous laitier électroconducteur
Industrial electroheat equipment – Test methods for electroslag remelting furnaces
Pour prix, voir catalogue en vigueur For price, see current catalogue IEC 2005
Droits de reproduction réservés

Copyright - all rights reserved Aucune partie de cette publication ne peut être reproduite ni utilisée sous quelque forme que ce soit et par aucun procédé, électronique ou mécanique, y compris la photocopie et les microfilms, sans l'accord écrit de l'éditeur. No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission,
3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch
Web: www.iec.ch CODE PRIX PRICE CODE Q Commission Electrotechnique InternationaleInternational Electrotechnical Commission

60779  IEC:2005 – 3 –
CONTENTS FOREWORD.5
1 Scope and object.9 2 Normative references.9 3 Terms and definitions.9 4 Type of tests and general conditions of their performance.15 4.1 Type of tests.15 4.2 General conditions of test performance.17 5 Recommendations for technical tests.17 5.1 Measurement of the effective stroke of the electrode ram motion.17 5.2 Measurement of the speed of the electrode motion.17 5.3 Measurement of the time interval for exchanging electrodes.17 5.4 Measurement of the open-circuit secondary voltage of the electroheat installation.17 5.5 Measurement of the electrical parameters of the secondary circuit of the electroheat installation.17 5.6 Measurement of the active power, reactive power and power factor of the electroheat installation.27 5.7 Measurement of the temperature of components which are subjected to strong magnetic field and/or radiated or converted heat.29 5.8 Measurement of the temperature rise of the cooling-water.31 5.9 Measurement of the cooling-water flow rate and heat losses.31 5.10 Measurement of the intensity of the magnetic field at or near an electroslag remelting furnace.31 5.11 Measurement of the melting rate of consumable electrode(s).31 5.12 Determination of the specific energy consumption.33 5.13 Measurement of vacuum parameters for a vacuum electroslag remelting furnace.33 5.14 Measurement of the pressure in the chamber of a pressurized electroslag remelting furnace.35 5.15 Measurement of the gas composition of an electroslag remelting furnace working under an inert gas atmosphere.35
Figure 1 – Example of a single-phase electroslag remelting furnace circuit.19 Figure 2 – Example of a three-phase electroslag remelting furnace circuit.25 Figure 3 – Example of a coaxial electroslag remelting furnace circuit.29

60779  IEC:2005 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION ____________
INDUSTRIAL ELECTROHEAT EQUIPMENT –
TEST METHODS FOR ELECTROSLAG
REMELTING 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 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 60779 has been prepared by IEC technical committee 27: Industrial electroheating equipment. This second edition cancels and replaces the first edition published in 1983 and constitutes a technical revision. The significant technical changes with respect to the previous edition are the additional technical tests described in 5.1, 5.2, 5.3, 5.9, 5.10, 5.11, 5.13, 5.14 and 5.15.

60779  IEC:2005 – 7 –
The text of this standard is based on the following documents: FDIS Report on voting 27/474/FDIS 27/494/RVD
Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. The committee has decided that the contents of this publication will remain unchanged until 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.

60779  IEC:2005 – 9 –
INDUSTRIAL ELECTROHEAT EQUIPMENT –
TEST METHODS FOR ELECTROSLAG
REMELTING FURNACES
1 Scope and object This International Standard applies to industrial electroslag remelting furnaces, the rated capacity of which is equal to, or greater than, 50 kg. This standard is applicable to industrial electroslag remelting furnaces having one or more electrodes and having different melting power supplies, such as alternating current, direct current, or low-frequency current. The object of this standard is the standardization of electroslag remelting furnace test conditions and methods to determine the main parameters and technical characteristics. This standard does not cover all possible test methods which may be carried out for the technical and economic assessment of furnaces. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition applies. For undated references, the latest edition of the referenced documents (including any amendments) applies. IEC 60050-841:2004, International Electrotechnical Vocabulary – Part 841: Industrial electroheat IEC 60398:1999, Industrial electroheating installations – General test methods IEC 60676:2002, Industrial electroheating equipment – Test methods for direct arc furnaces 3 Terms and definitions For the purposes of this document, the following terms and definitions, as well as those given in IEC 60050-841 and IEC 60676, apply. 3.1
electroslag remelting furnace remelting furnace in which the charge, usually a consumable electrode, is remelted by direct resistance heating of an electrical conductive molten slag NOTE The slag is contained in a mould (crucible). 3.2
electroheat installation with an electroslag remelting furnace complete assembly of electroheat equipment and electrical and mechanical accessories necessary for operation and utilization of an electroslag remelting furnace

60779  IEC:2005 – 11 –
NOTE The electrical equipment comprises, in particular, the conductors and switchgear in the power, control and regulating circuits, and the melting power supply(ies), when the device has its own melting power supply(ies). 3.3
power of an electroheat installation apparent power S (in kVA) or active power P (in kW) measured at the input of the supply line 3.4
power factor of an electroheat installation (cos 3) ratio of the active power to the apparent power measured at the input of the supply line 3.5
mould (crucible) of an electroslag remelting furnace water-cooled non-consumable container which shapes the ingot to be produced by the electroslag remelting process and which contains the molten slag 3.6
secondary electrical circuit of an electroslag remelting furnace electrical circuit which is closed by the melting power supply and may include a) output terminals of melting power supply; b) high-current feeder (busbars and/or cables); c) bus switches, if required; d) electrode clamp; e) electrode stub; f) consumable electrode or electrodes (depending on the connection system); g) conductive molten slag (not included in the short-circuit test); h) remelted ingot (not included in the case of the furnace with more than two electrodes); i) base plate (depending on the connection system) 3.7
consumable electrode solid part(s) in contact with the molten slag which carries the electrical current necessary for the melting operation and is constituted of the material necessary for the formation of the ingot 3.8
on-load voltage of an electroslag remelting furnace a) voltage which can be measured between the following two points (not applicable for a furnace with two electrodes corresponding to single-phase a.c. power supply): – the base plate; – the electrode clamping device(s) bringing the melting electrical current to the consumable electrode(s) or stub(s) NOTE See UF in Figures 1 and 2. b) for a furnace with two electrodes corresponding to single-phase a.c. power supply, voltage measured between the two electrode clamping devices c) in the case of an electroslag remelting furnace of a coaxial design for a single-phase a.c. power supply, the voltage measured between the electrode clamping device and the point of common connection of the multiple return conductors
NOTE See UF in Figure 3.
60779  IEC:2005 – 13 –
3.9
rated furnace frequency fn (Hz) value corresponding to the rated furnace current, if the furnace is built for a frequency range 3.10
rated furnace current In at rated frequency fn maximum current for continuous operation for which the furnace is designed 3.11
rated values of an electroslag remelting furnace rated values, including rated furnace current In, rated furnace power Pn, and rated furnace frequency fn, for which the furnace is designed 3.12
continuous operation of a furnace operation during which the solid ingot is produced and solidified and the consumable electrode is progressively added during the whole process 3.13
steady state of an electroslag remelting furnace state of a furnace in which, in continuous operation, electrical and thermal parameters have reached relatively constant values 3.14
melting rate of consumable electrode Vm (kg/min) quantity of remelted consumable electrode(s) measured in kilograms within a unit time (min) 3.15
specific energy consumption e (kWh/kg) ratio of the total amount of electric energy (kWh) measured at the input of the supply line, which is consumed by an electroheat installation for melting the charge in normal operating conditions agreed upon between the manufacturer and the user, to the weight of the ingot produced (kg) 3.16
water-cooled base plate of an electroslag remelting furnace water-cooled plate installed at the bottom of the mould to contain liquid metal and slag at the beginning of melting in any case, and connected to the cable(s) or busbar(s) to make sure that the current flows through the secondary electrical circuit in the case of fu
...