CSA C22.2 No. 66.2:21

Low voltage transformers — Part 2: General purpose transformers

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  CSA C22.2 No. 66.2:21

  August 2021

  
  

  Title: Low voltage transformers — Part 2: General purpose transformers

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CSA C22.2 No. 66.2:21

Low voltage transformers — Part 2: General purpose transformers

®A trademark of the Canadian Standards Association, operating as “CSA Group”

CSA Technical Committee on Industrial Products

R. P. de Lhorbe Schneider Electric Canada, Inc.,

North Vancouver, British Columbia, Canada

Category: Producer Interest

Chair

M. Smith Kitchener, Ontario, Canada

Category: General Interest

Vice-Chair

1. Z. Tsisserev AES Engineering Ltd.,

   Vancouver, British Columbia, Canada

   Category: User Interest

   Vice-Chair

   
   

2. M. Baldwin Baldwin Services Inc.,

Saskatoon, Saskatchewan, Canada

Category: General Interest

R. M. Bartholomew Electric Power Equipment Ltd.,

Vancouver, British Columbia, Canada

Category: Producer Interest

G. Benjamin ABB Electrification Canada SRI, Dorval, Québec, Canada Category: Producer Interest

R. B. Buckler ASCO Power Technologies Canada, Brantford, Ontario, Canada Category: Producer Interest

C. C. Cormier Alberta Municipal Affairs, Edmonton, Alberta, Canada Category: Regulatory Authority

1. Douglas QPS Evaluation Services Inc., Toronto, Ontario, Canada Category: General Interest

   
   

2. S. Driscoll OBIEC Consulting Ltd., Calgary, Alberta, Canada Category: User Interest

V. V. Gagachev Eaton,

Burlington, Ontario, Canada

Category: Producer Interest

R. Leduc Marex Canada Limited, Calgary, Alberta, Canada Category: User Interest

M. Lusk CSA Group,

Charlotte, North Carolina, USA

Category: General Interest

D. Mascarenhas Brampton, Ontario, Canada

Category: General Interest

S. Mercier Régie du bâtiment du Québec, Montréal, Québec, Canada Category: Regulatory Authority

M. Pilato Technical Safety BC,

Kelowna, British Columbia, Canada

Category: Regulatory Authority

L. Silecky Mersen Canada Toronto Inc., Mississauga, Ontario, Canada Category: Producer Interest

T. Simmons British Columbia Institute of Technology, Burnaby, British Columbia, Canada Category: General Interest

R. Yousef Electrical Safety Authority, Mississauga, Ontario, Canada Category: Regulatory Authority

C. Lee CSA Group,

Toronto, Ontario, Canada

Project Manager

CSA Subcommittee on Specialty Transformers

A. Leslie Curtiss Wright Controls, Stratford, Ontario, Canada

Chair

R. Bhasin Honeywell Limited/Honeywell Limitée, Scarborough, Ontario, Canada

R. Cojocaru Transformateur Marcus du Canada. Limitée/Marcus Transformer of Canada Ltd.,

Montréal, Québec, Canada

F. Dabiet Allanson International Inc., Markham, Ontario, Canada

J. Feenstra University of the Fraser Valley, Chilliwack, British Columbia, Canada

G. Franco ATC-Frost Magnetics Inc., Oakville, Ontario, Canada

S. Hasserjian Rex Power Magnetics Div. of Transfactor Industries

Inc.,

Concord, Ontario, Canada

D. C. Hutt Hammond Electronics, Div. of Hammond Manufacturing Company Ltd.,

Waterloo, Ontario, Canada

M. A. Khan Muskego, Wisconsin, USA

W. Meng CSA Group,

Taipei City, Taiwan

D. S. Patel Hammond Power Solutions, Inc., Guelph, Ontario, Canada

J. S. Taylor Basler Electric Company, Highland, Illinois, USA

W. Wong Hammond Power Solutions, Inc., Guelph, Ontario, Canada

1. Tiracchia CSA Group,

   Toronto, Ontario, Canada

   Project Manager

   AUGUST 16, 2021 tr1

   
   

   Standard for Safety for Low Voltage Transformers – Part 2: General Purpose Transformers Second Edition, Dated August 16, 2021

   Summary of Topics

   
   

   This new edition includes Alternate Temperature Rise Test Loading Methods

   
   

   The new and revised requirements are substantially in accordance with Proposal(s) on this subject dated January 22. 2021 and May 28, 2021.

   tr2 AUGUST 16, 2021

   
   

   No Text on This Page

   
   

   
   

   CSA Group

   CSA C22.2 No. 66.2:21

   Second Edition

   
   

   Underwriters Laboratories Inc. UL 5085-2

   Second Edition

   
   

   Low Voltage Transformers – Part 2: General Purpose Transformers

   
   

   August 16, 2021

   
   

   
   

   ANSI/UL 5085-2-2021

   Commitment for Amendments

   
   

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

   
   

   
   

   ISBN 978-1-4883-3536-5 © 2021 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.

   
   

   This Standard is subject to review within five years from the date of publication, and suggestions for its improvement will be referred to the appropriate committee. To submit a proposal for change, please send the following information to inquiries@csagroup.org and include "Proposal for change" in the subject line: Standard designation (number); relevant clause, table, and/or figure number; wording of the proposed change; and rationale for the change.

   
   

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   Copyright © 2021 Underwriters Laboratories Inc.

   
   

   UL's Standards for Safety are copyrighted by UL. Neither a printed nor electronic copy of a Standard should be altered in any way. All of UL's Standards and all copyrights, ownerships, and rights regarding those Standards shall remain the sole and exclusive property of UL.

   
   

   This ANSI/UL Standard for Safety consists of the Second Edition.

   
   

   The most recent designation of ANSI/UL 5085-2 as an American National Standard (ANSI) occurred on August 16, 2021. ANSI approval for a standard does not include the Cover Page, Transmittal Pages, Title Page (front and back), or the Preface.

   
   

   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.

   
   

   To purchase UL Standards, visit UL's Standards Sales Site at https://www.shopulstandards.com/HowToOrder.aspx or call toll-free 1-888-853-3503.

   
   

   AUGUST 16, 2021 CSA C22.2 No. 66.2:21 ♦ UL 5085-2 3

   CONTENTS

   Preface 5

   1. Scope 7

   2. Units of Measurement 7

   3. Referenced Publications 7

1. Mechanical Assembly 8

2. Enclosure 8

6.5 Openings 8

8 Connections 8

8.1 General 8

1. Pressure terminal connectors 8

2. Leads 8

3. Splice compartment 9

4. Wiring compartment 9

5. Wire bending space 9

6. Receptacles 10

11 Spacings and Insulation 11

11.4 Insulation used in lieu of spacings 11

1. Current-Carrying Parts 11

2. Cord-Connected Transformers 11

3. Strain Relief 12

17 Markings. 12

17.1 General 12

1. Environmental condition enclosures 12

2. Details 13

3. Wiring 13

18 Tests 15

21 Bonding Conductor Test 16

1. Temperature (Heating) Test 16

2. Voltage Measurement Test 17

3. Impedance Test 17

4. Dielectric Voltage-Withstand Test 17

   1. Applied potential 17

   2. Induced potential 18

5. Overload Test. 18

6. Repeated Dielectric Voltage-Withstand Test 19

7. Maximum Output Power and Short Circuit Tests for Line Cord-Connected Transformers 19

8. Short Circuit Test on Transformers with Output Receptacles 19

9. Maximum Output Power Test on Transformers with Output Receptacles 20

10. Leakage Current Test 20

11. Power Input Test 21

12. Lifting or Mounting Means Test 22

13. Strain Relief Test 22

TABLES 23

FIGURES 31

Annex A (Informative) Manufacturing and Production Line Tests

A1 Dielectric Voltage-Withstand Test 34

Annex C (Informative)

C1 French Translations of Markings 35

4 CSA C22.2 No. 66.2:21 ♦ UL 5085-2 AUGUST 16, 2021

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AUGUST 16, 2021 CSA C22.2 No. 66.2:21 ♦ UL 5085-2 5

Preface

This is the harmonized CSA Group and UL standard for low voltage transformers. It is the second edition of CSA C22.2 No. 66.2 and the second edition of UL 5085-2. This edition of CSA C22.2 No. 66.2/UL 5085- 2 supersedes the previous edition published on April, 2006.

This harmonized Standard was prepared by a Technical Harmonization Committee comprised of members from CSA Group, Underwriters Laboratories Inc. (UL), and representatives of the low voltage transformer manufacturing industry. The efforts and support of members of the Technical Harmonization Committee are gratefully acknowledged.

This Standard is considered suitable for use for conformity assessment within the stated scope of the Standard.

This Standard was reviewed by the CSA Subcommittee on Specialty Transformers, 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.

Application of Standard

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 uses the IEC format but is not based on, nor is it considered equivalent to, an IEC standard. This Standard is published as an equivalent standard for CSA Group and UL.

An equivalent standard is a standard that is substantially the same in technical content, except as follows: Technical national differences are allowed for codes and governmental regulations as well as those recognized as being in accordance with NAFTA Article 905, for example, because of fundamental climatic, geographical, technological, or infrastructural factors, scientific justification, or the level of protection that the country considers appropriate. Presentation is word for word except for editorial changes.

Reasons for Differences from IEC

The THC determined that the safe use of transformers and reactors is critically dependent on the electrical system in which they are intended to be installed. Significant investigation is required to assess safety and system compatibility issues that may lead to harmonization of traditional North American transformers and reactors with those presently addressed in the known IEC standards. The THC agreed such future investigation might be facilitated by completion of harmonization of North American standards for transformers and reactors.

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

6 CSA C22.2 No. 66.2:21 ♦ UL 5085-2 AUGUST 16, 2021

identified, a revision is to be proposed as soon as possible to each of the standards development organizations to more accurately reflect the intent.

Parts

The Standard for Low Voltage Transformers is divided into the following parts:

AUGUST 16, 2021 CSA C22.2 No. 66.2:21 ♦ UL 5085-2 7

PART 2: GENERAL PURPOSE TRANSFORMERS

1. Scope

   
   

   1. As noted in Low Voltage Transformers – Part 1: General Requirements, UL 5085-1, or CSA C22.2 No. 66.1, Low Voltage Transformers – Part 1: General Requirements, the requirements of Part 2 cover:

      
      

      1. Air-cooled transformers and reactors for general use;

         
         

      2. Autotransformers;

         
         

      3. Ferroresonant transformers;

         
         

      4. Cord-connected transformers; and

         
         

      5. Transformers incorporating overcurrent or over-temperature protective devices, transient voltage surge protectors, or capacitors.

1. These requirements do not cover Class 2 and Class 3 transformers (which are evaluated in Part 3).

   
   

2. Part 2 is intended to be used in conjunction with Part 1. The numbering of the clauses in Part 2 corresponds to the numbered clauses in Part 1. The requirements in Part 1 apply unless modified by Part 2.

1. Units of Measurement

   
   

   1. Values stated without parentheses are the requirement. Values in parentheses are explanatory or approximate information.

      
      

2. Referenced Publications

   
   

   1. Any undated reference to a code or standard appearing in the requirements of this Standard shall be interpreted as referring to the latest edition of that code or standard.

      
      

   2. When a reference is made to a code or standard, the product shall comply with the code or standard of the country in which the product is intended to be used.

      
      

   3. In Canada, general requirements applicable to this Standard are given in CSA C22.2 No. 0, General Requirements – Canadian Electrical Code, Part II.

      
      

   4. Throughout this Standard, the CSA standard references apply to products intended for use in Canada, and the UL standard references apply to products intended for use in the United States. Combined references are separated by a slash (“ / ”) to denote the difference between the applicable requirements specified for use in Canada and the United States.

      
      

   5. The following publications are referenced in this Standard:

CSA C22.2 No. 0, General Requirements – Canadian Electrical Code, Part II

CSA C22.2 No. 66.1, Low Voltage Transformers – Part 1: General Requirements

CSA C22.2 No. 94.2, Enclosures for Electrical Equipment, Environmental Considerations