NEMA-C50.41-2000.pdf

American National Standard for Polyphase Induction Motors for Power Generating Stations Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- ANSI C50.41-2000 American National Standard for Polyphase Induction Motors for Power Generating Stations Secretariat National Electrical Manufacturers Association Approved March 30, 2000 American National Standards Institute, Inc. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- ANSI C50.41-2000 Page ii Polyphase Induction Motors for Power Generating Stations American Approval of an American National Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been Nation a I met by the standards developer. Standard Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. The use of American National Standards is completely voluntary: their existence does not in any respect preclude anyone, whether he has approved the standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the standards. The American National Standards Institute does not develop standards and will in no circumstances give an interpretation of any American National Standard. Moreover, no person shall have the right or authority to issue an interpretation of an American National Standard in the name of the American National Standards Institute. Requests for interpretations shall be addressed to the secretariat or sponsor whose name appears on the title page of this standard. CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time. The procedures of the American National Standards Institute require that action be taken to reaffirm, revise, or withdraw this standard no later than five years from the date of approval. Purchasers of American National Standards may receive current information on all standards by calling or writing the American National Standards Institute. Published by National Electrical Manufacturers Association 1300 N. 17th Street, Rosslyn, Virginia 22209 Copyright O 2000 National Electrical Manufacturers Association All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without prior written permission of the publisher. Printed in the United States of America Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- Polyphase Induction Motors for Power Generating Stations ANSI C50.41-2000 Page iii TABLE OF CONTENTS Foreword . ix 1 2 3 4 5 6 7 8 9 Scope 1 1 . 1 Inclusions . 1 1.2 Exclusions 1 Applicable Standards . 1 Definitions 2 3.1 Design Type . 2 3.1.1 Design NT 2 3.1.2 Design HT 2 3.2 Service Factor 2 3.3 Classification of Insulation Systems . 2 Service Conditions . 2 4.1 Usual Service Conditions . 2 4.2 Unusual Service Conditions . 3 Basis of Rating . 4 5.1 Horsepower 4 5.2 Frequency . 4 5.3 Speed . 4 5.4 Voltage . 4 Horsepower Ratings of Multispeed Motors 5 6.1 General . 5 6.2 Constant Horsepower . 5 6.3 Constant Torque . 5 6.4 Variable Torque 5 6.4.1 Variable Torque Linear 5 6.4.2 Variable Torque Square . 5 Insulation Systems . 6 Service Factor 6 8.1 Service Factor of 1 .O 6 8.2 Service Factor of 1 . 15 6 8.2.1 General 6 8.2.2 Temperature Rise 6 Temperature 7 9.1 General . 7 . . . . Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- ANSI (250.41 -2000 Polyphase Induction Motors for Power Generating Stations Page iv 9.2 9.3 9.4 9.5 Temperature Rise . 7 9.2.1 Barometric Pressure 7 9.2.2 Cooling Air . 7 9.2.3 Reference Ambient Temperature 8 9.2.4 Totally Enclosed Water-Air-Cooled Motors 8 Resistance Method for Temperature Measurement 8 Embedded-Detector Method for Temperature Measurement 8 9.4.1 Resistance Temperature Detectors . 8 9.4.2 Locations of Embedded Detectors . 8 Motor Lead Total Temperature 8 10 11 12 13 14 15 Torques 8 Starting Requirements . 9 11.1 Starting Capabilities 9 11.2 Number of Starts 9 11.3 Starting Information Nameplate . 9 Load Inertia (Wk') 10 12.1 Design NT Motors 10 12.2 Design HT Motors 10 Variation from Rated Voltage and Rated Frequency . 10 13.1 Running 1 0 13.2 Starting . 11 13.2.1 Performance Characteristics . 11 13.2.20ther Load-Torque Characteristics . 11 13.3 Momentary Operation . 11 13.4 Effects Of Unbalanced Voltages On The Performance Of Polyphase Squirrel-Cage Induction Motors 12 13.4.1 Effect on Performance - General . 13 13.4.2Voltage Imbalance Defined 13 13.4.3Torques 14 13.4.4 Full-Load Speed . 14 13.4.5Currents . 14 Bus Transfer or Reclosing . 14 14.1 General . 14 14.2 Slow Transfer or Reclosing 14 14.3 Fast Transfer or Reclosing . 15 14.4 Recommendations . 15 Power Factor Correction 16 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- Polyphase Induction Motors for Power Generating Stations ANSI C50.41-2000 Page v 15.1 Corrective WAR 16 15.2 Capacitors . :17 15.3 Autotransformer Starters 17 16 Efficiency 17 17 Stator current pulsations 17 18 Surge Capabilities of AC Winding with Form-Wound Coils . 18 18.1 General . 18 18.2 Surge Capacitors 18 18.3 Stator Windings 18 18.4 Method of Test . 18 18.5 Test Voltage Adjustment 19 19 Motors Operating on an Ungrounded System . 19 20 Occasional Excess Current 19 21 Operation of Induction Motors from Variable-Frequency or Variable-Voltage Power Supplies, or Both . 1 9 22 Belt, Chain, and Gear Drive . 19 23 Aseismatic Capablllty 20 23.1 Earthquake Damage 20 . 23.2 System Requirements 20 23.3 Motor Requirements . 20 23.4 Supporting Base Structure . 20 24 Airborne Sound 21 24.1 Sound Quality . 21 24.2 Sound Measurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 24.3 Sound Power Levels . 21 25 Bearings . 23 25 . 1 Horizontal Motors . 23 25.2 Vertical Motors . 23 25.3 Oil Lubrication 23 25.4 Antifriction Bearings . 23 25.5 Shaft Currents 23 26 Lubrication System,., 23 26.1 Supplied From the Driven Equipment System . 23 26.2 Auxiliary Lubrication System 23 27 Overspeed . 24 28 Construction Features 24 28.1 Protection of Motor Leads from Mechanical Damage 24 28.2 Drainage . 24 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- ANSI C50.41-2000 Page vi Polyphase Induction Motors for Power Generating Stations 28.3 Cooler-Tube Leakage . 24 28.4 Space Heaters 24 28.5 Horizontal Sleeve Bearing Motors 24 28.6 Grounding . 25 29 Terminal Housing and Boxes . 25 29.1 General . 25 29.2 Dimensions and Volumes 25 29.3 Accessory Leads 25 30 Coupling End Play and Rotor Float 25 30.1 General . 25 30.2 Flexible Couplings 25 30.3 Assembly 25 31 Motor Vibration . 25 31.1 General . 25 31.2 Limits 28 31.3 Reed Frequency of Vertical Motors 28 31.3.1 Static Deflection . 28 31.3.2Radial Resonant Frequency 28 31.3.3Determining System Resonant Frequency 28 32 High-Potential Tests . 29 32.1 Safety Precautions and Test Procedure . 29 32.2 Test Voltage . 29 33 Motor with Sealed Windings - Conformance Tests . 29 33.1 Test for Stator Which Can Be Submerged . 29 33.2 Test for Stator Which Cannot Be Submerged 29 34 Tests on Complete Motors . 30 34.1 General . 30 34.2 Tests on Motors Completely Assembled in the Factory . 30 34.2.1 Required Factory Tests 30 34.2.2 Optional Tests. . 30 34.3 Tests on Motors Not Completely Assembled in the Factory 31 34.3.1 Required Tests . 31 34.3.2 Recommended Field Tests 31 35 Rotation 31 35.1 Nameplate 31 35.2 Unidirectional Fans . 31 36 Nameplate 31 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- Polyphase Induction Motors for Power Generating Stations ANSI C50.41-2000 Page vi¡ 36.1 Construction . 31 36.2 Marking 31 37 Documentation . 32 37.1 37.2 37.3 37.4 37.5 37.6 37.7 37.8 37.9 General . 32 Motor Data 32 Performance Curves 32 Performance Da ta 33 Accessories 33 Test Reports . 33 Drawings 33 Instruction Manual 33 37.8.1 General 33 37.8.2 Equipment Handling . 33 37.8.3 Equipment Storage 34 Optional Documentation . 34 Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- ANSI C50.41-2000 Page viii Polyphase Induction Motors for Power Generating Stations Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- STD-NEMA C5O-YL-ENGL ZOO0 m 6470247 0521108 89b Polyphase Induction Motors for Power Generating Stations ANSI C50.41-2000 Page ix Foreword (This Foreword is not a part of American National Standard for Polyphase Induction Motors for Power Generating Stations, ANS C50.41-2000.) This standard was developed by the Subcommittee on Polyphase Induction Motors and Generators of American National Standards Committee on Rotating Electrical Machinery, C50. The subcommittee membership reflects wide industrial experience in both the manufacture and use of polyphase induction motors intended for application in power generating stations. Portions of this standard are extracted from NEMA Standards Publication for Motors and Generators, NEMA MGI-1998, copyrighted by the National Electrical Manufacturers Association, and reproduced by permission. Suggestions for improvement of this standard will be welcome. They should be sent to the American National Standards Institute, 11 West 42nd Street, New York, New York 10036. This standard was processed and approved for submittal to ANSI by American National Standards Committee on Rotating Electrical Machinery, C50. Committee approval of the standard does not necessarily imply that all committee members voted for approval. At the time it approved this standard, the C50 Committee had the following members: W. R. McCown, Chair D. M. Threlkel, Secretary Organization Represented Representative Association of Iron and Steel Engineers . Stanley C. Houk Chemical Manufacturers Association . David Pace Crane Manufacturers Association of America David C. Wendt Electrical Apparatus Service Association . David L. Gebhart Thomas Bishop Prebel Christensen (Alt.) Electric Light a maximum water temperature of 32°C at the intake of the heat exchanger for water-cooled motors; and a minimum ambient temperature of -15“C3 or, when water cooling is used, a minimum ambient temperature of +5OC b) Exposure to a maximum altitude of 3300 feet (1000 meters) above sea level (see 9.2.1) c) Exposure to a moderate combination of conducting or abrasive dust (such as coal, fly ash, etc.) with sulfur fumes, moisture, etc., as encountered in usual power plant applications ' Available from the American National Standards Institute, 11 West 42nd Street, New York, NY 10036 and from the Institute of Electrical and Electronics Engineers, 345 East 47th Street, New York, NY 1 O01 7. * Available form the National Electrical Manufacturers Association, 1300 North 17th Street, Rosslyn, VA 22209. Outdoor motors may be exposed to ambient temperature below -i 5°C. Operation of motors in ambient temperatures below -1 5°C requires additional consideration with respect to the lubrication system, relative f that is, operating 1 hour at specified 1.15 SF temperature rise values is approximately equivalent to operating 2 hours at the temperature rise specified for a motor with a 1 .O SF. Motors rated at 1 .I 5 SF shall have a data sheet section listing the expected temperature rises at the 1 .O SF and the 1.1 5 SF operating points when operating at rated voltage. Copyright National Electrical Manufacturers Association Provided by IHS under license with NEMALicensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/19/2007 08:33:54 MDTNo reproduction or networking permitted without license from IHS -,-,- Polyphase Induction Motors for Power Generating Stations ANSI (250.41-2000 Page 7 9 Temperature 9.1 General All temperatures shall be determined in accordance with ANSIAEEE 112. Unless otherwise specified, motors rated 500 hp or greater and 2300 volts or greater shall be furnished with embedded temperature detectors in accordance with 9.4. 9.2 Temperature Rise When operated at rated voltage and rated frequency, the observable temperature rise of the motor with Class F stator winding electrical insulation, above the temperature of the cooling air, shall not exceed the values in Table 1. For motors equipped with embedded detectors, this method shall be used to demonstrate conformity with this standard. NOTE-Table 1 applies to a particular motor rating (that is, a 1.0 or 1.15 SF), and it is not intended or implied that this information be applied as a dual rating to an individual motor. Table 1 LIMITING