CSA C22.2 No. 254:05

National Standard of Canada

(reaffirmed 2019)

Motor Control Centres

REVISED OCTOBER 2019

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  Revision History

  CSA C22.2 No. 254:05, Motor Control Centres

  
  

  Update No. 3 — October 2018	Revision symbol (in margin)
  Cover, Copyright page, Preface, Clauses 8.2.1.1, 8.2.1.2, 8.2.7.1, 9.3.4, and 9.15.2.2, Table 17, and Annex C	∆

  
  

  National Standard of Canada — October 2019

  Outside front cover, National Standard of Canada text, and title page. This Standard has been developed in compliance with Standards Council of Canada requirements for National Standards of Canada. It has been published as a National Standard of Canada by CSA Group.

  
  

  Association of Standardization and Certification NMX-J-353-ANCE-2006

  Second Edition

  
  

  Δ CSA Group

  CSA C22.2 No. 254-05

  First Edition

  
  

  Underwriters Laboratories Inc. UL 845

  Fifth Edition

  
  

  Motor Control Centers

  
  

  August 31, 2005

  
  

  (Title Page Reprinted: October 31, 2018)

  
  

  ANSI/UL 845-2018

  Commitment for Amendments

  
  

  This standard is issued jointly by the Association of Standardization and Certification (ANCE), the Canadian Standards Association (CSA), and Underwriters Laboratories Inc. (UL). Comments or proposals for revisions on any part of the standard may be submitted to ANCE, CSA, or UL at any time. Revisions to this standard will be made only after processing according to the standards development procedures of ANCE, CSA, and UL. CSA and UL will issue revisions to this standard by means of a new edition or revised or additional pages bearing their date of issue. ANCE will incorporate the same revisions into a new edition of the standard bearing the same date of issue as the CSA and UL pages.

  
  

  Copyright © 2006 ANCE

  
  

  Rights reserved in favour of ANCE.

  
  

  ISBN 1-55397-107-8

  © 2005 Canadian Standards Association

  
  

  All rights reserved. No part of this publication may be reproduced in any form whatsoever without the prior permission of the publisher.

  
  

  ISBN 0-7629-1100-X

  Copyright © 2005 Underwriters Laboratories Inc.

  
  

  Revisions to this Standard will be made by issuing revised or additional pages bearing their date of issue. A UL Standard is current only if it incorporates the most recently adopted revisions, all of which are itemized on the transmittal notice that accompanies the latest set of revised requirements.

  
  

  The most recent designation of ANSI/UL 845 as an American National Standard (ANSI) occurred on August 1, 2005.

  
  

  This ANSI/UL Standard for Safety, which consists of the Fifth edition, is under continuous maintenance, whereby each revision is ANSI approved upon publication. Comments or proposals for revisions on any part of the Standard may be submitted to UL at any time. Proposals should be submitted via a Proposal Request in UL's On-Line Collaborative Standards Development System (CSDS) at https://csds.ul.com.

  
  

  The Department of Defense (DoD) has adopted UL 845 on April 20, 1993. The publication of revised pages or a new edition of this Standard will not invalidate the DoD adoption.

  CONTENTS

  
  

  Preface 5

  1. Scope 8

     1. Products covered 8

     2. Products not covered 8

     3. Equipment 8

     4. Units of measurement 9

  2. Normative references 9

  3. Definitions 9

  4. Application information and components 10

     4.2 Components 10

  5. Characteristics 11

     1. General 11

     2. Voltage ratings 11

     3. Current 11

     4. Short-circuit 12

  6. Markings and product information 12

     1. Identification 12

     2. Product information 12

     3. Marking 13

     4. Installation instructions 22

  7. Normal service and transport conditions 22

     1. General 22

     2. Normal service conditions 22

  8. Construction and performance requirements 22

     1. General assembly 22

     2. Construction requirements 25

     3. Performance requirements 48

  9. Motor control centre tests 51

     1. General 51

     2. Calibration tests 51

     3. Temperature-rise tests 52

     4. Overvoltage and undervoltage test 54

     5. Dielectric voltage-withstand tests (after temperature-rise test or overvoltage/undervoltage test) 54

     6. Current-withstand test 55

     7. Dielectric voltage-withstand tests (after current-withstand test) 56

     8. Contactor overload test 56

     9. Dielectric voltage-withstand test (after contactor overload test) 57

     10. Short-circuit tests — bus structure 57

     11. Dielectric voltage-withstand test (after short-circuit test - bus structure) 61

     12. Short-circuit (standard-level) tests for motor control centre units 62

     13. Dielectric voltage-withstand test (after standard-level unit short-circuit test) 64

     14. Trip-out test for circuit-breakers (after standard-level unit short-circuit test) 65

     15. Short-circuit (high-level) test for motor control centre units 66

     16. Dielectric voltage-withstand test (after high-level short-circuit test — motor control centre units) 68

     17. Trip-out test for circuit-breakers (after high-level unit short-circuit test) 69

     18. Strength of insulating base and support tests 69

     19. Comparative deflection test 70

     20. Autotransformer starter test 70

     21. Factory tests 70

  10. Application 70

Annexes

A (Normative) Short-circuit test circuit calibration 115

1. General 115

2. Alternating-current circuits 115

   1. General 115

   2. Available current of 10 000 A or less 115

   3. Available current more than 10 000 A 116

   4. Recovery voltage 117

3. Direct-current circuits 119

4. Instrumentation for test currents above 10 000 A 120

5. Calibration characteristics for a protective device 121

6. Peak let-through current, Ip 122

7. Application 123

B (Informative) Languages 124

C (Normative) References 126

D (Informative) Standards for components 128

E (Normative) — For Canada only — Guidelines for certification of fire pump controllers 130

F (Informative) Factory tests 131

G (Normative) Requirements for service entrance 132

H (Informative) Application information 135

1. General 135

2. Definitions 135

3. Classifications 135

   1. Classes and types 135

   2. Classes of motor control centres 135

   3. Circuit wiring 136

4. Characteristics 137

   1. Motor-controller size ratings 137

   2. Basis for short-circuit current rating of motor control centres 138

   3. Instructions for installation, operation, and maintenance 139

5. Service and storage conditions 139

   1. Usual service and installation conditions 139

   2. Storage temperature 140

6. Construction 140

   1. Construction information 140

   2. Ground fault tests (production tests) 141

7. Application input 141

   1. Technical information needed to supply a motor control centre (application input) . . . 141

   2. Application of short-circuit current ratings 142

Preface

This is the common ANCE, CSA, and UL standard for motor control centres. It is the second edition of NMX-J-353-ANCE, the first edition of CSA C22.2 No. 254, and the fifth edition of UL 845. This edition of UL 845 supersedes the previous edition published on February 15th, 1995.

This common standard was prepared by the Association of Standardization and Certification (ANCE), the Canadian Standards Association (CSA), and Underwriters Laboratories Inc. (UL). The efforts and support of the CANENA Technical Harmonization Subcommittee 17D — Motor Control Centres are gratefully appreciated.

The present Mexican standard was developed by the CT CDI Control y Distribucion Industrial from the Comite de Normalizacion de la Asociacion de Normalizacion y Certificacion, A.C., CONANCE, with the collaboration of the motor control centres, manufacturers, and users.

This standard was reviewed by the CSA Subcommittee on Motor Control Centres, under the jurisdiction of the CSA Technical Committee on Industrial Products and the CSA Strategic Steering Committee on Requirements for Electrical Safety, and has been formally approved by the CSA Technical Committee.

This standard will be submitted to the Standards Council of Canada (SCC) for approval as a National Standard of Canada. This standard has been approved as an American National Standard by the American National Standards Institute (ANSI).

A UL standard is current only if it incorporates the most recently adopted revisions, all of which are itemized on the transmittal notice that accompanies the latest set of revised requirements.

Where reference is made to a specific number of samples to be tested, the specified number is to be considered a minimum quantity.

Note: Although the intended primary application of this standard is stated in its scope, it is important to note that it remains the responsibility of the users of the standard to judge its suitability for their particular purpose.

Level of harmonization

This standard is published as an identical standard for ANCE, CSA, and UL.

An identical standard is a standard that is exactly the same in technical content except for national differences resulting from conflicts in codes and governmental regulations. Presentation is word for word except for editorial changes.

Interpretations

The interpretation by the standards development organization of an identical or equivalent standard is based on the literal text to determine compliance with the standard in accordance with the procedural rules of the standards development organization. If more than one interpretation of the literal text has been identified, a revision is to be proposed as soon as possible to each of the standards development organizations to more accurately reflect the intent.

ANCE effective date

The effective date for ANCE will be announced through the Diario Oficial de la Federación (Official Gazette) and is indicated on the cover page.

CSA effective date

The effective date for CSA International will be announced through CSA Informs or a CSA certification notice.

UL effective date

As of August 31, 2005 all products Listed or Recognized by UL must comply with the requirements in this standard except for clauses, figures, and tables in the following list, which are effective August 31, 2007.

Clauses 5.4.2, 6.3.30.1–6.3.30.3, 6.3.50, 8.1.2.1, 8.1.7.1, and 8.2.4.5.

Between August 31, 2005 and August 31, 2007, new product submittals to UL may be evaluated under all requirements in this standard or, if requested in writing, evaluated under presently effective requirements only. The presently effective requirements are contained in the fourth edition of UL 845.

A UL effective date is one established by Underwriters Laboratories Inc. and is not part of the ANSI approved standard.

Foreword (CSA)

The Canadian Standards Association (CSA) develops standards under the name Canadian Standards Association, and provides certification and testing under the name CSA International. CSA International provides certification services for manufacturers who, under license from CSA, wish to use the appropriate registered CSA Marks on certain products of their manufacture to indicate conformity with CSA Standards.

CSA Certification for a number of products is provided in the interest of maintaining agreed-upon standards of quality, performance, interchangeability and/or safety, as appropriate. Where applicable, certification may form the basis for acceptance by inspection authorities responsible for enforcement of regulations. Where feasible, programs will be developed for additional products for which certification is desired by producers, consumers, or other interests. In performing its functions in accordance with its objectives, CSA does not assume or undertake to discharge any responsibility of the manufacturer or any other party. The opinions and findings of the Association represent its professional judgement given with due consideration to the necessary limitations of practical operation and state of the art at the time the Standard is processed.

Products in substantial accord with this Standard but which exhibit a minor difference or a new feature may be deemed to meet the Standard providing the feature or difference is found acceptable utilizing appropriate CSA International Operating Procedures. Products that comply with this Standard shall not be certified if they are found to have additional features which are inconsistent with the intent of this Standard. Products shall not be certifiable if they are discovered to contravene applicable laws or regulations.

Testing techniques, test procedures, and instrumentation frequently must be prescribed by CSA International in addition to the technical requirements contained in Standards of CSA. In addition to markings specified in the Standard, CSA International may require special cautions, markings, and instructions that are not specified by the Standard.

Some tests required by CSA Standards may be inherently hazardous. The Association neither assumes nor accepts any responsibility for any injury or damage that may occur during or as the result of tests, wherever performed, whether performed in whole or in part by the manufacturer or the Association, and whether or not any equipment, facility, or personnel for or in connection with the test is furnished by the manufacturer or the Association.

Manufacturers should note that, in the event of the failure of CSA International to resolve an issue arising from the interpretation of requirements, there is an appeal procedure: the complainant should submit the matter, in writing, to the Secretary of the Canadian Standards Association.

If this Standard is to be used in obtaining CSA Certification please remember, when making application for certification, to request all current Amendments, Bulletins, Notices, and Technical Information Letters that may be applicable and for which there may be a nominal charge. For such information or for further information concerning CSA Certification, please address your inquiry to Applications and Customer Service, CSA International, 178 Rexdale Boulevard, Toronto, Ontario, Canada M9W 1R3.

Motor Control Centres

1. Scope

   
   

   1. Products covered

      
      

      1. This standard applies to motor control centres to be used in accordance with the U.S. National Electrical Code, ANSI/NFPA 70, the Canadian Electrical Code, Part I, CSA C22.1, and the Mexican Electrical Installations (Utility), NOM-001-SEDE.

         
         

      2. These requirements cover motor control centres for use on circuits having available short-circuit currents not more than 200 000 A rms symmetrical or 200 000 A dc.

         
         

      3. This standard applies to single- and three-phase 50 and 60 Hz and dc motor control centres rated not more than 600 V ac or 1 000 V dc.

         
         

      4. Requirements for fire pump controllers are as provided in Annex C, item 11.

1. Products not covered

   These requirements do not cover switchboards or panelboards intended for the control of electric light and power circuits, nor do they cover an individual unit for this purpose. Such units, however, that consist of manually or automatically operated switches, branch-circuit or service-circuit circuit-breakers,

   overcurrent-protective devices, or the like may be used within a motor control centre.

   
   

2. Equipment

   
   

   1. A motor control centre can contain, but is not limited to, any combination of equipment such as the following:

      
      

      1. full-voltage reversing or non-reversing combination motor control units;

         
         

      2. full-voltage multispeed combination motor control units;

         
         

      3. reduced-voltage part-winding, wye-delta or auto-transformer combination motor control units;

         
         

      4. solid-state industrial controllers, such as adjustable-speed drives, programmable controllers, protective relays, and the like;

         
         

      5. lighting or distribution panelboards;

         
         

      6. feeder-tap units;

         
         

      7. incoming-line equipment, such as main lugs, fusible switch, isolation switch, or circuit-breaker;

         
         

      8. control or lighting transformers;

         
         

      9. special equipment assemblies;

         
         

      10. combination contactor units.

          
          

   2. The foregoing equipment can contain, but is not limited to, such items as pushbuttons, selector switches, indicating lights, control transformers, control circuit fuses, and auxiliary devices incorporated as an integral part of the units.