1、NEMA Standards PublicationNational Electrical Manufacturers AssociationANSI/NEMA C50.41-2012 Polyphase InductionMotors for PowerGenerating Stations Copyright 2013 by National Electrical Manufacturers Association ANSI/NEMA C50.41-2012 American National Standard Polyphase Induction Motors for Power Ge
2、nerating Stations Secretariat National Electrical Manufacturers Association Approved July 17, 2012 American National Standards Institute, Inc. C50.41-2012 Page ii Copyright 2013 by National Electrical Manufacturers Association Approval of an American National Standard requires verification by ANSI t
3、hat the requirements for due process, consensus, and other criteria for approval have been met by the standards developer. 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. Subst
4、antial 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 no
5、t 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 gi
6、ve 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 sp
7、onsor 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 CAUTION NOTICE: This American National Standard may be revised or withdrawn at any time.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
8、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 Co
9、pyright 2013 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. American National Sta
10、ndard C50.41-2012 Page iii Copyright 2013 by National Electrical Manufacturers Association TABLE OF CONTENTS Foreword ix 1 Scope 1 1.1 Inclusions . 1 1.2 Exclusions 1 2 Applicable Standards . 1 3 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 Class
11、ification of Insulation Systems 2 4 Service Conditions . 2 4.1 Usual Service Conditions . 2 4.2 Unusual Service Conditions . 2 5 Basis of Rating 4 5.1 Horsepower 4 5.2 Frequency 4 5.3 Speed . 4 5.4 Voltage . 4 6 Horsepower Ratings of Multispeed Motors . 5 6.1 General 5 6.2 Constant Horsepower 5 6.3
12、Constant Torque 5 6.4 Variable Torque . 5 6.4.1 Variable Torque Linear 5 6.4.2 Variable Torque Square 5 7 Insulation Systems 6 8 Service Factor . 6 8.1 Service Factor of 1.0 6 8.2 Service Factor of 1.15 6 8.2.1 General 6 8.2.2 Temperature Rise 6 9 Temperature 7 9.1 General 7 C50.41-2012 Page iv Copy
13、right 2013 by National Electrical Manufacturers Association 9.2 Temperature Rise 7 9.2.1 Barometric Pressure 7 9.2.2 Cooling Air . 7 9.2.3 Reference Ambient Temperature 7 9.2.4 Totally Enclosed Water-Air-Cooled Motors . 8 9.3 Resistance Method for Temperature Measurement 8 9.4 Embedded-Detector Meth
14、od for Temperature Measurement . 8 9.4.1 Resistance Temperature Detectors 8 9.4.2 Locations of Embedded Detectors 8 9.5 Motor Lead Total Temperature 8 10 Torques . 8 11 Starting Requirements . 9 11.1 Starting Capabilities . 9 11.2 Number of Starts 9 11.3 Starting Information Nameplate . 9 12 Load In
15、ertia (Wk2) . 9 12.1 Design NT Motors 9 12.2 Design HT Motors 10 13 Variation from Rated Voltage and Rated Frequency . 10 13.1 Running 10 13.2 Starting . 10 13.2.1 Performance Characteristics . 10 13.2.2 Other Load-Torque Characteristics . 10 13.3 Momentary Operation 11 13.4 Effects Of Unbalanced Vo
16、ltages On The Performance Of Polyphase Squirrel-Cage Induction Motors . 12 13.4.1 Effect on Performance - General 13 13.4.2 Voltage Imbalance Defined . 13 13.4.3 Torques . 13 13.4.4 Full-Load Speed 14 13.4.5 Currents . 14 14 Bus Transfer or Reclosing . 14 14.1 General 14 14.2 Slow Transfer or Reclos
17、ing 14 14.3 Fast Transfer or Reclosing 15 14.4 Recommendations . 15 15 Power Factor Correction 16 C50.41-2012 Page v Copyright 2013 by National Electrical Manufacturers Association 15.1 Corrective KVAR 17 15.2 Capacitors 17 15.3 Autotransformer Starters . 17 16 Efficiency . 17 17 Stator current puls
18、ations 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 Ind
19、uction Motors from Variable-Frequency or Variable-Voltage Power Supplies, or Both 19 22 Belt, Chain, and Gear Drive . 19 23 Aseismatic Capability 19 23.1 Earthquake Damage 19 23.2 System Requirements . 20 23.3 Motor Requirements 20 23.4 Supporting Base Structure . 20 24 Airborne Sound 20 24.1 Sound
20、Quality 20 24.2 Sound Measurement . 20 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 Auxi
21、liary Lubrication System 23 27 Overspeed . 24 28 Construction Features . 24 28.1 Protection of Motor Leads from Mechanical Damage . 24 28.2 Drainage 24 C50.41-2012 Page vi Copyright 2013 by National Electrical Manufacturers Association 28.3 Cooler-Tube Leakage 24 28.4 Space Heaters . 24 28.5 Horizon
22、tal Sleeve Bearing Motors . 24 28.6 Grounding 24 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
23、Limits . 28 31.3 Reed Frequency of Vertical Motors . 28 31.3.1 Static Deflection 28 31.3.2 Radial Resonant Frequency 28 31.3.3 Determining 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 Confor
24、mance 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 Mot
25、ors 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 C50.41-2012 Page vii Copyright 2013 by National Electrical Manufacturers Association 36.1 Construction . 31 3
26、6.2 Marking 31 37 Documentation 32 37.1 General 32 37.2 Motor Data . 32 37.3 Performance Curves 32 37.4 Performance Data 32 37.5 Accessories . 33 37.6 Test Reports 33 37.7 Drawings 33 37.8 Instruction Manual 33 37.8.1 General 33 37.8.2 Equipment Handling 33 37.8.3 Equipment Storage 33 37.9 Optional
27、Documentation 34 C50.41-2012 Page viii Copyright 2013 by National Electrical Manufacturers Association C50.41-2012 Page ix Copyright 2013 by National Electrical Manufacturers Association Foreword (This Foreword is not a part of American National Standard Polyphase Induction Motors for Power Generati
28、ng Stations, ANSI C50.41-2012.) 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
29、 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 MG1-1998, copyrighted by the National Electrical Manufacturers Association, and reproduced by permission. Sugg
30、estions 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 Ma
31、chinery, 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 W. C. Buckson, Secretary Organization Represented Representative Associat
32、ion 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
33、32g113C at the intake of the heat exchanger for water-cooled motors; and a minimum ambient temperature of -15g113C3or, when water cooling is used, a minimum ambient temperature of +5g113C b) Exposure to a maximum altitude of 3300 feet (1000 meters) above sea level (see 9.2.1) c) Exposure to a modera
34、te combination of conducting or abrasive dust (such as coal, fly ash, etc.) with sulfur fumes, moisture, etc., as encountered in usual power plant applications 4.2 Unusual Service Conditions Unusual Service conditions should be brought to the attention of those responsible for the design, manufactur
35、e, application, and operation of the motor. Among such unusual conditions are: 1Available 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 10017. 2Available form
36、the National Electrical Manufacturers Association, 1300 North 17th Street, Rosslyn, VA 22209. 3Outdoor motors may be exposed to ambient temperature below -15g113C. Operation of motors in ambient temperatures below -15g113C requires additional consideration with respect to the lubrication system, rel
37、ative fits and clearances between dissimilar metals, and the transition temperature of the various metal parts. For applications below -15g113C, the motor manufacturer should be consulted. C50.41-2012 Page 3 Copyright 2013 by National Electrical Manufacturers Association a) Exposure to: 1. extreme a
38、mounts of abrasive or conducting dust 2. chemical fumes, combustible dust, or flammable gases 3. nuclear radiation 4. oil vapor, salt laden air, or steam 5. seismic events in excess of those specified in Section 23 6. abnormal shock or vibration b) Operation in pits, entirely enclosed boxes, poorly
39、ventilated rooms, or damp locations c) Operation at speeds other than rated d) Conditions under which the variation from rated voltage or frequency, or both, exceeds limits given in Section 13 of this standard e) Conditions under which the alternating-current supply voltage is unbalanced by more tha
40、n 1 percent (see 13.4) f) Mechanical loads involving thrust or overhang g) Operation in an inclined position h) Harmonic voltage factor exceeding 3 percent (see MG 1-30.1.2.1) i) Repeated starts in excess of those described in Section 11 C50.41-2012 Page 4 Copyright 2013 by National Electrical Manuf
41、acturers Association Part II: Ratings 5 Basis of Rating Induction motors covered by this standard shall be rated on a continuous-duty basis. The output rating shall be expressed in horsepower available at the shaft at a specified speed, frequency, and voltage. 5.1 Horsepower Motor horsepower ratings
42、 shall be as follows: 200 600 1,750 4,500 10,000 17,000 30,000 250 700 2,000 5,000 11,000 18,000 35,000 300 800 2,250 5,500 12,000 19,000 40,000 350 900 2,500 6,000 13,000 20,000 45,000 400 1,000 3,000 7,000 14,000 22,500 50,000 450 1,250 3,500 8,000 15,000 25,000 - 500 1,500 4,000 9,000 16,000 27,5
43、00 - 5.2 Frequency Stator frequency shall be 60 Hz. For other frequencies, contact the manufacturer. 5.3 Speed Synchronous speed ratings at 60 Hz, in revolutions per minute, shall be as follows: 3, 600 720 400 277 1, 800 600 360 257 1, 200 514 327 240 900 450 300 225 NOTEIt is not practical to build
44、 motors of all horsepower ratings at all speeds. For ratings not shown, the manufacturer should be consulted. 5.4 Voltage Voltage ratings shall be as follows: 460 2 300 6 600 575 4 000 13 200 C50.41-2012 Page 5 Copyright 2013 by National Electrical Manufacturers Association NOTEIt is not practical t
45、o build motors of all horsepower ratings for all of these voltages. In general, based on motor design and manufacturing considerations, typical motor voltages are as shown in the following table: Voltage Horsepower 460 or 575 200 to 600 2,300 200 to 5,000 4,000 200 to 10,000 6,600 1,000 to 15,000 13
46、,200 3,500 to 50,000 6 Horsepower Ratings of Multispeed Motors 6.1 General The horsepower ratings of multispeed motors shall be selected in accordance with 6.2 through 6.4. 6.2 Constant Horsepower The horsepower rating for each rated speed shall be selected from 5.1. 6.3 Constant Torque The horsepow
47、er rating for the highest rated speed shall be selected from 5.1. The horsepower rating for each lower speed shall be determined by multiplying the horsepower rating at the highest speed by the ratio of the lower synchronous speed to the highest synchronous speed. 6.4 Variable Torque 6.4.1 Variable
48、Torque Linear Torque varies directly with speed, and the horsepower rating for the highest rated speed shall be selected from 5.1. The horsepower rating for each lower speed shall be determined by multiplying the horsepower rating at the highest speed by the square of the ratio of the lower synchron
49、ous speed to the highest synchronous speed. 6.4.2 Variable Torque Square The torque varies as the square of speed, and the horsepower rating for the highest rated speed shall be selected from 5.1. The horsepower rating for each lower speed shall be determined by multiplying the horsepower rating at the highest speed by the cube of the ratio of the lower synchronous speed to the highest synchronous speed. C50.41-2012 Page 6 Copyright 2013 by National Electrical Manufacturers Association Part III: Performance 7 Insulation Systems Motors
