C22.2 No. 66.1-06

(reaffirmed 2020)

Low Voltage Transformers — Part 1: General Requirements

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Update No. 2

C22.2 No. 66.1-06

December 2013

Note: For information about the Standards Update Service or if you are missing any updates, go to

shop.csa.ca or e-mail techsupport@csagroup.org.

Title: Low Voltage Transformers — Part 1: General Requirements — originally published April 2006

Revisions issued: Update No. 1 — November 2012

The following revisions have been formally approved and are marked by a vertical line in the margin on the attached replacement pages:

• Update your copy by inserting these revised pages.

• Keep the pages you remove for reference.

  CSA Group

  CSA C22.2 No. 66.1-06

  First Edition

  
  

  Underwriters Laboratories Inc. UL 5085-1

  First Edition

  
  

  Low Voltage Transformers – Part 1: General Requirements

  
  

  April 17, 2006

  
  

  (Title Page Reprinted: December 6, 2013)

  
  

  ANSI/UL 5085-1-2013

  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 any time. 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 1-55436-830-8 © 2006 CSA Group

  
  

  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 periodic review, and suggestions for its improvement will be referred to the appropriate committee. To submit a proposal for change, please send the following information to inquires@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 © 2013 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.

  
  

  The most recent designation of ANSI/UL 5085-1 as an American National Standard (ANSI) occurred on December 6, 2013. 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.

  
  

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  DECEMBER 6, 2013 CSA C22.2 NO. 66.1-06  UL 5085-1 3

  CONTENTS

  Preface 5

  1. Scope 7

  2. Definitions 8

  3. General 9

     1. Components 9

     2. Reference Publications 10

3.3 Units of Measurement ....................................................... .10B

4 Construction ...................................................................... .10B

5 Mechanical Assembly .............................................................. .10B

1. Enclosures 13

   1. General 13

   2. Nonmetallic enclosures 14

   3. Enclosures – specific environmental conditions 15

   4. Mounting 15

   5. Openings 16

   6. Barriers for openings 17

   7. Covers 17

2. Corrosion Resistance 18

3. Connections 20

   1. General 20

   2. Wiring terminals 20

   3. Wire-binding screws and studs 20

   4. Pressure terminal connectors 21

   5. Leads 22

4. Internal Wiring 22

5. Grounding 22

6. Spacings and Insulation 24

   1. General 24

   2. Insulating material for mounting of low voltage live parts 25

   3. Coil insulation 25

   4. Insulation used in lieu of spacings 26

   5. Double insulation 28

7. Switches, Protective Devices, and Wiring Devices 28

   1. General 28

   2. Switches 28

12.3 Protective devices ......................................................... .28A

13 Current-Carrying Parts ............................................................ .28A

14 Cord-Connected Transformers ..................................................... .28B

15 Strain Relief ..................................................................... .28B

1. Bushings for Low Voltage Wiring 29

2. Markings 31

   1. General 31

   2. Miscellaneous 32

3. Tests 33

4. Insulating Barriers Test 34

5. Pullout, Bending, and Twisting Tests 34

6. Bonding Conductor Test 34

7. Moisture Absorption Test 35

8. Hot, Flaming Oil Test 35

   4 CSA C22.2 NO. 66.1-06  UL 5085-1 DECEMBER 6, 2013

9. Enclosure Tests 36

   1. General 36

   2. Compression test 36

   3. Outlet box cover support and impact tests 37

   4. Polymeric enclosure impact test 37

10. Induced Potential 38

11. Temperature (Heating) Test 38

Annex A (Informative)

A1 Production Line Dielectric Voltage Withstand Test 52

A2 Production Line Grounding Continuity Test 53

Annex B (Informative)

B1 Component Standards 54

Annex C (Informative)

C1 French Translation of Markings 55

DECEMBER 6, 2013 CSA C22.2 NO. 66.1-06  UL 5085-1 5

Preface

This is the harmonized CSA Group and UL standard for low voltage transformers. It is the first edition of CSA C22.2 No. 66.1 and the first edition of UL 5085-1. This harmonized standard has been jointly revised on December 6, 2013. For this purpose, CSA Group and UL are issuing revision pages dated December 6, 2013.

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 C22.2 No. 66, 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 has been approved by the American National Standards Institute (ANSI) as an American National 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 to be 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 Technical Harmonization Committee identified the following IEC Standard within the scope of this standard: IEC 61558-1 (1998-07), Safety of power transformers, power supply units, and similar - Part 1: General requirements.

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.

APRIL 17, 2006 CSA C22.2 NO. 66.1-06  UL 5085-1 7

PART 1: GENERAL REQUIREMENTS

1. Scope

   
   

   1. These requirements cover the following types of transformers:

      
      

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

         
         

      2. General purpose autotransformers;

         
         

      3. Ferroresonant transformers;

         
         

      4. Class 2 and Class 3 transformers (which are evaluated in accordance with Part 3);

         
         

      5. Cord-connected transformers (which are evaluated in accordance with Part 2);

         
         

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

         
         

      7. Permanently-connected transformers.

         
         

   2. These transformers are intended to be used in accordance with the National Electrical Code, ANSI/NFPA 70, or CSA C22.1, the Canadian Electrical Code, Part I. The Canadian Electrical Code defines low voltage as any voltage from 31 to 750 V inclusive and high voltage as any voltage above 750

      V. The National Electrical Code, ANSI/NFPA 70, defines low voltage as any voltage up to 600 V, nominal. Therefore, low voltage transformers intended for use in Canada may be rated above 600 V up to 750 V. Low voltage transformers intended for use in the United States are rated up to 600 V. Where information in clauses and tables in this standard reference voltage ranges, the limit of 600 V applies in the United States, while the limit of 750 V applies in Canada.

      
      

   3. The standard does not cover the following transformers:

      
      

      1. Direct plug-in types;

         
         

      2. Neon;

         
         

      3. Liquid-immersed;

         
         

      4. Variable voltage (Variac);

         
         

      5. Low voltage landscape;

         
         

      6. Swimming pool and spa:

         
         

      7. Ignition;

         
         

      8. High intensity lighting;

         
         

      9. Toy;

         
         

      10. Fluorescent lamp types;