IEC-TR-62296-2003.pdf

TECHNICAL REPORT IEC TR 62296 First edition 2003-03 Considerations of unaddressed safety aspects in the Second Edition of IEC 60601-1 and proposals for new requirements Etudes des aspects de sécurité non énoncés dans la seconde édition de la CEI 60601-1 et propositions de nouvelles prescriptions Reference number IEC/TR 62296:2003(E) Copyright International Electrotechnical Commission Provided by IHS under license with IECLicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/08/2007 23:48:51 MSTNo reproduction or networking permitted without license from IHS -,-,- Publication numbering As from 1 January 1997 all IEC publications are issued with a designation in the 60000 series. For example, IEC 34-1 is now referred to as IEC 60034-1. Consolidated editions The IEC is now publishing consolidated versions of its publications. For example, edition numbers 1.0, 1.1 and 1.2 refer, respectively, to the base publication, the base publication incorporating amendment 1 and the base publication incorporating amendments 1 and 2. Further information on IEC publications The technical content of IEC publications is kept under constant review by the IEC, thus ensuring that the content reflects current technology. Information relating to this publication, including its validity, is available in the IEC Catalogue of publications (see below) in addition to new editions, amendments and corrigenda. Information on the subjects under consideration and work in progress undertaken by the technical committee which has prepared this publication, as well as the list of publications issued, is also available from the following: IEC Web Site (www.iec.ch) Catalogue of IEC publications The on-line catalogue on the IEC web site (http:/www.iec.ch/searchpub/cur_fut.htm) enables you to search by a variety of criteria including text searches, technical committees and date of publication. On-line information is also available on recently issued publications, withdrawn and replaced publications, as well as corrigenda. IEC Just Published This summary of recently issued publications (http:/www.iec.ch/online_news/ justpub/jp_entry.htm) is also available by email. Please contact the Customer Service Centre (see below) for further information. Customer Service Centre If you have any questions regarding this publication or need further assistance, please contact the Customer Service Centre: Email: custserviec.ch Tel: +41 22 919 02 11 Fax: +41 22 919 03 00 Copyright International Electrotechnical Commission Provided by IHS under license with IECLicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/08/2007 23:48:51 MSTNo reproduction or networking permitted without license from IHS -,-,- TECHNICAL REPORT IEC TR 62296 First edition 2003-03 Considerations of unaddressed safety aspects in the Second Edition of IEC 60601-1 and proposals for new requirements Etudes des aspects de sécurité non énoncés dans la seconde édition de la CEI 60601-1 et propositions de nouvelles prescriptions PRICE CODE IEC 2003 Copyright - all rights reserved No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission, 3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, Switzerland Telephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmailiec.ch Web: www.iec.ch V For price, see current catalogue Commission Electrotechnique Internationale International Electrotechnical Commission Copyright International Electrotechnical Commission Provided by IHS under license with IECLicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/08/2007 23:48:51 MSTNo reproduction or networking permitted without license from IHS -,-,- 2 TR 62296 IEC:2003(E) CONTENTS FOREWORD 4 INTRODUCTION 5 1Scope and object. 6 1.1Scope. 6 1.2Object. 6 2Recommendations . 6 2.1Summary of all recommendations prepared by SC 62A/WG 14 . 6 2.2Recommendation sheets. 9 2.2.1Separation: Reliability of component impedance . 9 2.2.2Separation: Non-complying CREEPAGE DISTANCE and AIR CLEARANCES.10 2.2.3Mains supply transformers: Overload test 11 2.2.4Mains supply transformers: Short circuit and overload tests.12 2.2.5CREEPAGE DISTANCE and AIR CLEARANCES: Values.13 2.2.6Dielectric strength14 2.2.7Failure of components: Evidence of reliability 15 2.2.8ENCLOSURES and protective covers 16 2.2.9INTERNALLY POWERED EQUIPMENT: 110 % of the maximum supply voltage17 2.2.10 CREEPAGE DISTANCES and AIR CLEARANCES: Values under 1 mm .18 2.2.11 Separation: Secondary circuit impedance limit LEAKAGE CURRENT.19 2.2.12 ENCLOSURES and PROTECTIVE COVERS: Lampholder/switching device20 2.2.13 Fixing, prevention of maladjustment: Torque test .21 2.2.14 Batteries not intended to be changed by OPERATOR: Lithium batteries22 2.2.15 Excessive temperatures: Ambient temperatures.23 2.2.16 Continuous LEAKAGE CURRENTS: Different SUPPLY MAINS24 2.2.17 ENCLOSURE and protective covers: EQUIPMENT in ambulances 25 2.2.18 Dielectric strength: Voltages appearing from external sources .26 2.2.19 Testing switch mode power supply units (SMPSU).27 2.2.20 Failure of an electrical component: Time periodicity for detection.29 2.2.21 Environmental conditions: Compliance paragraph30 2.2.22 Limitation of voltage and/or energy: Capacitance.31 2.2.23 LEAKAGE CURRENTS: Presence of 45 k resistor in Figure 2132 2.2.24 Humidity preconditioning treatment: Exception from requirement .33 2.2.25 Dielectric strength: EQUIPMENT containing floating circuits34 2.2.26 General requirements for tests: Measurement uncertainty35 2.2.27 CREEPAGE DISTANCES and AIR CLEARANCES: Interpolated values36 2.2.28 Overheating: Change of load resistance.37 2.2.29 Mains operated EQUIPMENT with additional power source: Integrity of external protective earth 38 2.2.30 Rechargeable batteries: No OPERATOR/USER maintenance39 2.2.31 Isolation from the SUPPLY MAINS: Symbol for single pole switch 40 2.2.32 Sequence of testing: Clause 52 before Clause 1941 2.2.33 SINGLE FAULT CONDITION: ENCLOSURE LEAKAGE CURRENT from INTERNALLY POWERED EQUIPMENT.42 2.2.34 Marking on the outside of EQUIPMENT: Type and rating of fuses43 2.2.35 Excessive temperatures: APPLIED PARTS not intended to supply heat44 Copyright International Electrotechnical Commission Provided by IHS under license with IECLicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/08/2007 23:48:51 MSTNo reproduction or networking permitted without license from IHS -,-,- TR 62296 IEC:2003(E) 3 2.2.36 Mains supply transformers: Use of PTCs as protective devices45 2.2.37 Components and general assembly: Reliability of components.46 2.2.38 Definition of APPLIED PART: EQUIPMENT worn by PATIENTS47 2.2.39 Construction: Triple insulated winding wire 48 2.2.40 CREEPAGE DISTANCES and AIR CLEARANCES: Dielectric strength test versus CREEPAGE DISTANCES and AIR CLEARANCES.49 2.2.41 Cord anchorages/ Cord guards: In mobile unit with APPLIANCE COUPLER.50 2.2.42 ACCOMPANYING DOCUMENTS: on CD-ROM or Electronic File Format 51 2.2.43 INTERNAL ELECTRICAL POWER SOURCE: Requirements for lithium batteries 52 2.2.44 Dielectric strength: Differences between B-d and B-e.53 2.2.45 Excessive temperatures: Thermocouple instead of resistance method .54 2.2.46 Mains fuses and OVER-CURRENT RELEASEs: Fuses in CLASS II EQUIPMENT.55 2.2.47 Plug top power supply56 2.2.48 Connecting cords between EQUIPMENT parts: Other applications 57 2.2.49 MULTIPLE PORTABLE SOCKET-OUTLET58 2.2.50 Separation, DEFIBRILLATION-PROOF APPLIED PART: multiple APPLIED PARTS.59 2.2.51 Separation, APPLIED PART: Hand held flexible shafts.60 2.2.52 Protective earthing: No-load voltage of 6 V maximum 61 2.2.53 Foot-operated control devices: Protection against entry of liquids62 2.2.54 Mains supply transformers .63 2.2.55 Dielectric strength: Reliability of components to bridge A-a2 and B-a .64 2.2.56 Dielectric strength: A-e in switch mode power supply units (SMPSU).65 Bibliography66 Index of defined terms.67 Copyright International Electrotechnical Commission Provided by IHS under license with IECLicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/08/2007 23:48:51 MSTNo reproduction or networking permitted without license from IHS -,-,- 4 TR 62296 IEC:2003(E) INTERNATIONAL ELECTROTECHNICAL COMMISSION _ CONSIDERATIONS OF UNADDRESSED SAFETY ASPECTS IN THE SECOND EDITION OF IEC 60601-1 AND PROPOSALS FOR NEW REQUIREMENTS FOREWORD 1)The IEC (International Electrotechnical Commission) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of the 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, the IEC publishes International Standards. 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. The 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 the 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 National Committees. 3)The documents produced have the form of recommendations for international use and are published in the form of standards, technical specifications, technical reports or guides and they are accepted by the National Committees in that sense. 4)In order to promote international unification, IEC National Committees undertake to apply IEC International Standards transparently to the maximum extent possible in their national and regional standards. Any divergence between the IEC Standard and the corresponding national or regional standard shall be clearly indicated in the latter. 5)The IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with one of its standards. 6)Attention is drawn to the possibility that some of the elements of this technical report may be the subject of patent rights. The IEC shall not be held responsible for identifying any or all such patent rights. The main task of IEC technical committees is to prepare International Standards. However, a technical committee may propose the publication of a technical report when it has collected data of a different kind from that which is normally published as an International Standard, for example “state of the art”. IEC 62296, which is a technical report, has been prepared by subcommittee 62A: Common aspects of electrical equipment used in medical practice, of IEC technical committee 62: Electrical equipment in medical practice. The text of this technical report is based on the following documents: Enquiry draftReport on voting 62A/398/CDV62A/414/RVC Full information on the voting for the approval of this technical report 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 2005. At this date, the publication will be reconfirmed; withdrawn; replaced by a revised edition, or amended. Copyright International Electrotechnical Commission Provided by IHS under license with IECLicensee=IHS Employees/1111111001, User=Wing, Bernie Not for Resale, 03/08/2007 23:48:51 MSTNo reproduction or networking permitted without license from IHS -,-,- TR 62296 IEC:2003(E) 5 INTRODUCTION At the Sydney meeting in August 1994, IEC subcommittee (SC) 62A established a procedure under which working group (WG) 14 would develop recommendations regarding problems of interpretation or application of IEC 60601-1. WG 14 is made up of experts with particular expertise in testing according to the requirements of IEC 60601-1. Many of the experts on WG 14 are employed by test houses with a long history of applying IEC 60601-1 to MEDICAL ELECTRICAL EQUIPMENT. While the National Committee members of SC 62A nominate these experts, their recommendations were not to be formally adopted through any official voting procedure. To reinforce this process, the Subcommittee specifically directed that the following note appear on every page of the resulting informational circular: IMPORTANT NOTE: Per the 62A decision at Sydney (see RM3755/SC62A, August 1994), the 62A Secretary is circulating this recommendation, prepared by 62A/WG14, regarding problems of interpretation or application of IEC 60601-1 to all P-Member NCs. This recommendation/interpretation is the result of considerations by a group of nominated experts and has not been formally adopted through any NC voting procedure. Distribution is only for information. The plan approved in Sydney called for the 62A Secretary to circulate these recommendations to the member National Committees via an informational (INF) document. At the time this Technical Report was prepared, three documents containing 56 recommendations had been circulated (documents 62A/221/INF, 62A/264/INF and 62A/284/INF). While the quality of the technical work of WG 14 is widely recognized and applauded, the overall process has achieved less than originally hoped. The INF documents have not proved a particularly successful way of getting this information to those who could use it most. The WG 14 recommendations are largely unknown beyond the people actively involved in the work of SC 62A. Several alternatives have been explored. These include making the individual recommendation sheets available on the Internet either through the IEC Web Site, the web site of a participating National Committee, or the web site of an interested third party. However, concerns over intellectual property and control of distribution have proved extremely difficult to overcome. At the November 2000, meeting of SC 62A in Tokyo, the subcommittee discussed ways and means for achieving a wider distribution of the WG 14 recommendations. At the conclusion of this discussion, the subcommittee instructed the Secretariat to develop a Technical Report (TR) based on the published recommendations of WG 14. This Techni