ISO INTERNATIONAL STANDARD 14839-4 First edition 2012-03-15 Mechanical vibration Vibration of rotating machinery equipped with active magnetic bearings Part 4: Technical guidelines Vibrations mécaniques - - Vibrations de machines rotatives équipées de paliers magnétiques actifs - Partie 4: Lignes directrices techniques Reference number ISO 14839-4:2012(E) X @ISO 2012 ISO 14839-4:2012(E) COPYRIGHT PROTECTED DOCUMENT ISO 2012 All rights reserved. Unless otherwise specified, 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 either ISO at the address below or ISO's member body in the country of the requester. ISO copyright office Case postale 56 : CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyright@iso.org Web www.iso.org Published in Switzerland ii @ ISO 2012 - All rights reserved ISO 14839-4:2012(E) Contents Page Foreword V 1 Scope 2 Normative references 3 Terms and definitions. 4 Active magnetic bearing system architecture.. 2 5 Important differences between magnetic bearings and conventional bearings. 3 5.1 Some advantages of active magnetic bearings. 3 5.2 Some disadvantages of active magnetic bearings 5 5.3 Comparison among rolling, fluid film and magnetic bearings... 6 6 System condition monitoring. .6 6.1 6.2 Excess rotor shaft displacement (radial x, y, and axial z) 6.3 Excess of rotor expansion.. 8 6.4 Overload of bearing (over current of bearing coil). 6.5 Bearing temperature high . 6.6 Overspeed of rotor.. 8 6.7 Power supply defect.. 6.8 Battery power defect 6.9 Controller temperature high 8 6.10 Cooling. 9 7 Environmental factors 9 7.1 Introduction 9 7.2 Environmental category tables. 10 7.3 Explosive atmosphere types. 13 8 System requirements . 13 8.1 Estimation of bearing load. 13 8.2 Limitation of dl/dt for laminated bearings 14 8.3 Balancing 16 8.4 Location of bearings and transducers 17 8.5 Fault recovery and fault handling 17 8.6 Signal processing 7 8.7 Monitoring system. 17 9 Touchdown bearings.. 18 9.1 Touchdown bearing requirements 18 9.2 Design of touchdown bearings. 9.3 Touchdown bearing monitoring 20 9.4 Touchdown test methods. 20 10 Preventive inspection. 22 10.1 .22 Introduction. 10.2 22 Regular inspection and maintenance 10.3 Condition monitoring (recommendation) 22 10.4 Inspection checklist.... .23 Annex A (informative) Sizing of magnetic bearings. 24 Annex B (informative) Example of a design specification check list, .27 Annex C (informative) Example conditions for acceptance tests .29 Annex D (informative) Touchdown test method example. ..30 Annex E (informative) Example of system limitations (current/voltage saturation). .32 Annex F (informative) Unbalance control . ili @ ISO 2012 - All rights reserved