57A Specific Numbering and Formatting Rules for National Differences

GUIDELINES AND RULES FOR NUMBERING NATIONAL DIFFERENCES

TO IEC-BASED ANCE/CSA/UL STANDARDS

CONTENTS

1 General Guidelines for Numbering IEC-Based Co-Published Standards

1.1 General

1.2 Application of Numbering Procedures for Different Types of IEC Standards

1.3 Identification of the Base IEC Standard

2 General Rules for Numbering National Differences to IEC-Based Co-Published Standards

3 Rules and Examples for Numbering National Differences to Part 1 Standards

3.1 IEC Foreword/IEC Introduction

3.2 Definitions

3.3 Clauses and Subclauses

3.4 Tables and Figures

3.5 Annexes

4 Rules and Examples for Numbering National Differences to Part 2 Standards

4.1 IEC Foreword/IEC Introduction

4.2 Definitions

4.3 Clauses and Subclauses

4.4 Tables and Figures

4.5 Annexes

1 General Guidelines for Numbering IEC-Based Co-Published Standards

1.1 General

1.1.1 The numbering procedures for IEC-based co-published standards with other Standards Development Organizations (SDO) are to provide for consistent numbering of elements and identification of national differences from the relevant IEC standards that serve as the base documents.

1.1.2 The general numbering procedures in this section and specific numbering procedures in Section 2, General Rules for Numbering National Differences to IEC-Based Co-Published Standards, Section 3, Rules and Examples for Numbering National Differences to Part 1 Standards, and Section 4, Rules and Examples for Numbering National Differences to Part 2 Standards, are to be applied to standards that are published as IEC-based co-published standards.

1.1.3 An IEC-based co-published standard incorporates the complete text of the correlating IEC standard. Any differences in requirements or wording from the base IEC text are also provided. These necessary differences are called national differences. The base IEC standard plus national differences from the base IEC requirements form the IEC-based co-published standard.

1.1.4 A national difference from the base IEC text shall be identified by the specific types defined in 2.11, and shall specify the paragraph, clause, subclause, table, figure, or annex to which the national difference is associated.

1.1.5 A national difference from the base IEC text shall be placed either before the base IEC Standard (CSA) or within the text of the standard immediately following the corresponding IEC clause, subclause, table, figure number, or annex that is to be modified (UL). See 2.5 for an exception to this rule. This applies to all national differences except for national differences due to equivalent terms, editorial corrections, references to component standards and regulatory requirements, which may also be provided in the form of an annex following the body of the standard or when it is necessary to add a national difference at the beginning of a clause or annex. See 2.5.

Note: All national differences from the base IEC text are included in the (ANCE, CSA, and/or UL) versions of the standard. While the technical content is the same in each organization’s version, the format and presentation of the national differences may differ.

1.2 Application of Numbering Procedures for Different Types of IEC Standards

1.2.1 Some IEC standards are written as stand-alone standards to be used in their entirety, as applicable. However, other IEC standards have been written in multiple parts, which usually include General Requirements (Part 1) and Particular Requirements (Part 2). In some cases, IEC standards have been written in multiple part standards which contain more than two parts.

1.2.2 Generally, when IEC standards are written in multiple parts, the Part 1 General Requirements are written to include those requirements applicable to all products in a broad product category. The Part 2 Particular Requirements are then written to supplement the Part 1 and to cover more specific requirements applicable to a narrower range of products. Multiple Part 2 standards may exist which relate to a single Part 1 standard. The Part 2 standard is incomplete without using the corresponding Part 1 standard.

1.2.3 The numbering procedures documented in Sections 2 to 4 have been created with various formats in mind. All of the rules are presented with instructions for numbering Part 1 standards and Part 2 standards. The procedures also apply to other multiple-part standards which contain more than two parts. Any standard that is considered to be stand-alone and does not have separate parts shall be numbered using the instructions provided for the Part 1 standards.

1.3 Identification of the Base IEC Standard

1.3.1 Because an IEC-based co-published standard uses the text of the correlating IEC standard as the base document, it is necessary to identify the specific IEC standard and edition including amendments, if any, used as the base text of the ANCE/CSA/UL Standard. This information is provided in the SDO Preface of the co-published standard.

2 General Rules for Numbering National Differences to IEC-Based Co-Published Standards

2.1 These general rules are intended to provide guidance in the numbering of national differences. For specific rules on numbering, see Section 3 for Part 1 standards and Section 4 for Part 2 standards.

2.2 An IEC-based co-published standard shall directly incorporate the IEC text and numbering structure.

2.3 The IEC does not number every paragraph in a clause. When the IEC standard is reproduced, the clauses will not be renumbered and clause numbers will not be added to the un-numbered IEC paragraphs. However, the preferred method for numbering national differences is to number each paragraph, clause, subclause, table, or figure within the national difference. The clauses, subclauses, tables, or figures of a national difference that applies to an annex would also be individually numbered. This numbering scheme allows for easy referencing to a specific portion of the national difference. However, there are instances where it would be acceptable to leave clauses, subclauses, tables, or figures unnumbered. The following are examples of instances where the elements within a national difference may not be numbered:

a)the THC or working group prefer that the individual elements within national differences not be numbered, and the numbering style used is logical; or

b)the Publication Coordinator chooses to have unnumbered elements with national differences. See the Editorial Leeway Guidance Document.

Note: If a national difference has only one paragraph, the individual paragraph is not numbered.

2.4 The “DV” suffix is a unique identifier used to distinguish the material as being a national difference from the base IEC text. Every national difference shall start with a clause, subclause, table, or figure number or annex letter followed by an additional suffix “DV”. Also note that the “DV” prefix will be used when adding an annex. See 3.5 and 4.5.

2.5 A national difference that applies to an entire annex or clause shall follow the annex or clause to which it applies. In some cases, it may be necessary to include a national difference at the beginning of a clause or annex. Reasons for using this approach include the following:

a) the national difference would be more logically placed before a related clause or clauses; and

b) placing the national difference before an IEC annex or clause would identify upfront which requirements are applicable, eliminating the risk of users applying potentially lengthy IEC requirements before realizing there is a national difference at the end of the requirements.

2.6 In general, when modifying or deleting a clause, subclause, table, figure, or annex in a Part 1 or Part 2 standard, the same number is used with the addition of the “DV” suffix.

2.7 When deleting a Part 1 table or figure that the IEC Part 2 does not modify, this original table or figure will not be present in the co-published Part 2 standard. In this scenario, the national difference in the Part 2 standard shall still be assigned the same number as the relevant table or figure to be deleted with the addition of the “DV” suffix.

2.8 In general, to add a clause, subclause, table, or figure in a Part 1 standard, a new number that is one number greater than the last relevant IEC clause or subclause number is used, with the addition of the “DV” suffix.

2.9 In general, to add a clause, subclause, table, or figure in a Part 2 standard, the new item is assigned a number which is the base IEC Part 2 main clause number with a suffix 101.DV, 102.DV, 103.DV, etc.

Note: The “101” numbers are used by the IEC in the numbering of IEC Part 2 standards. See also 4.3.5.

2.10 On the first line of the national difference, just following the clause, subclause, table, or figure number, or annex letter, every national difference shall be designated with one of the national difference types described in 2.11 (i.e., DR, D1, D2, DC, or DE). The national difference designation type identifies the reason why the national difference is included in the harmonized standard. The designation type should not be repeated on subsequent lines of the same national difference. See the national difference examples in Section 3 and Section 4.

Note: Although the default policy for IEC-based co-published standards is to assign only one designation type to a national difference, there are situations where a national difference clause may contain subclauses with different type designations. A THC, harmonization working group, or other stakeholder involved in the development of the harmonized standard may request assigning more than one type designation to a national difference based on technical necessity. The following example illustrates a national difference with more than one type designation.

7.1DV.1 D1 Modification of 7.1 by replacing it with the following:

7.1DV.1.2 Control circuit protective devices

7.1DV.1.2.1 DR Control circuit transformer and conductors of control circuits shall be protected against overcurrent in accordance with Annex DVB, Table DVB.3, Ref. No. 15.

7.1DV.1.2.2 D2 Conductors for control circuits shall be provided with overcurrent protection in each ungrounded conductor, located no more than 305 mm from the point where the conductor is connected to the source of power. Direct leads measuring a maximum of 305 mm long or printed-wiring assemblies having no connection external to the equipment are not required to be protected.

2.11 One of the following designations shall be applied to each national difference in an IEC-based co-published standard as specified in 2.10:

DR - These are National Differences based on the national regulatory requirements.

D1 - These are national differences which are based on basic safety principles and requirements, elimination of which would compromise safety for consumers and users of products.

D2 -These are national differences from IEC requirements based on existing safety practices. These requirements reflect national safety practices, where empirical substantiation (for the IEC or national requirement) is not available or the text has not been included in the IEC standard.

DC - These are national differences based on the component standards and will not be deleted until a particular component standard is harmonized with the IEC component standard.

DE - These are national differences based on editorial comments or corrections.

2.12 Following the national difference designation, every national difference shall include a description of how the national difference changes the IEC text, or instructions on how the national difference is applied to the IEC requirement. One of the following words shall be used to describe how the national difference text is to be applied to the base text:

Addition / Add An addition entails adding a complete new numbered clause, subclause, table, figure, or annex. Addition is not meant to include adding select words to the base IEC text.

Modification / Modify A modification is an altering of the existing base IEC text such as the addition, replacement, or deletion of certain words or the replacement of an entire clause, subclause, table, figure, or annex of the base IEC text.

Deletion / Delete – A deletion entails complete deletion of an entire numbered clause, subclause, table, figure, or annex without any replacement text.

2.13 While the information is typically provided by indicating Addition, Modification, and Deletion, additional phrases or paragraphs may be provided if further clarification is needed. For example, the following statements could be used to provide additional information:

1DV.1 D1 Modification by adding the following text after “playing with the appliances by young children”:

7.6DV D2 Modification of Clause 7.6 by adding the following text:

Figure 12DV D1 Addition of Figure to Replace Test Probe B of IEC 61032 (see clauses 1DV.1, 8.1.1DV, 20.2DV):

2.14 A national difference in a Part 2 standard shall be identified with a description as to which source text the national difference applies, i.e., the Part 1 or the Part 2 standard. In these cases, additional explanation is required to adequately identify to which part the national difference is applicable. For example, the following statements could be used:, “Modification of Clause #.# of the Part 1” or “Modification of Clause #.# of the Part 2.”

2.15 The national difference text shall be placed on the next line following the instruction statements indicating Addition, Modification, or Deletion.

2.16 Exceptions shall not be used in national differences to IEC-based co-published standards. The requirement shall be rewritten to remove the use of the word “exception.”

2.17 In cases where the numbering or structure of the Part 2 IEC standard does not align with the numbering structure of the Part 1 IEC standard, the Part 2 national differences shall still follow the Part 1 and Part 2 numbering procedures. However, detailed instruction shall be included to clarify to which standard (part) each national difference applies, to avoid numbering confusion in the Part 1 and Part 2 standards. See the following example:

8.1DV D2 Modify Clause 7.1DV of the Part 1 by adding the following:

8.1DV.1 D2 Combination Motor Controllers

8.1DV.1.1 An adjustable instantaneous-trip setting means of a circuit breaker or self-protected control device that is accessible without opening a door or removing a cover shall be constructed so that a stop to limit the maximum setting is able to be installed. Directions for the installation of the stop shall be included with the complete controller.

8.1DV.1.2 A self-protected combination motor controller shall have a means that is visible with the device mounted as intended with the door or cover of the enclosure opened that indicates which function (overload or short-circuit) has operated.

3 Rules and Examples for Numbering National Differences to Part 1 Standards

3.1 IEC Foreword/IEC Introduction

Note: An IEC Standard may also include a Preface. The rules specified in Clauses 3.1.1 to 3.1.3 also apply to an IEC Preface.

3.1.1 Rule: The general rules for numbering a national difference as specified in Sections 1 and 2 shall be applied to a national difference to the IEC Foreword/IEC Introduction. The preferred method for numbering national differences is to number each clause or subclause of the national difference text individually.

3.1.2 Rule: The following wording regarding the IEC numbering system shall be added as a national difference at the end of the IEC foreword text. If no other national differences are being adopted, do not add this national difference.

The numbering system in the standard uses a space instead of a comma to indicate thousands and uses a comma instead of a period to indicate a decimal point. For example, 1 000 means 1,000 and 1,01 means 1.01.

3.1.3 Rule: A national difference or differences to the IEC Foreword/IEC Introduction shall be placed at the end of the foreword/introduction and given the clause numbers DV.1, DV.2, etc., numbered sequentially.

Examples of National Differences for IEC Foreword/IEC Introduction

a) Add an IEC Foreword/IEC Introduction paragraph:

DV.1 DE Add the following after the second IEC Foreword note:

b) Modify an IEC Foreword/IEC Introduction paragraph:

(IEC TEXT)

Annexes C, L, M and N form an integral part of this standard.

Annexes A, B, D, E, F, G, H, J, O and P are for information only.

(NATIONAL DIFFERENCE)

DV.1 DE Modify the IEC Foreword notes as follows:

Annexes M, DVC, DVD, and DVE form an integral part of this standard.

Annexes A, B, C, D, E, F, G, H, J, L, N, O, and P are for information only.

c) Delete an IEC Foreword/IEC Introduction paragraph:

(IEC FOREWORD TEXT)

Annex D is an integral part of this standard.

(NATIONAL DIFFERENCE)

DV.1 D2 Delete the IEC Foreword text and add the following:

Annex D is not applicable.

3.2 Definitions

3.2.1 Rule: The general rules for numbering national difference as specified in Sections 1 and 2 shall be applied to a national difference for an IEC definition. The preferred method for numbering national differences is to number each clause or subclause of the national difference text individually. If a national difference has only one paragraph, the individual paragraph is not numbered. See the example in 3.2.5.

3.2.2 Rule: When adding a definition, the logical placement of the national difference shall be taken into consideration. Consider whether the national difference is related to the base IEC text or whether it is a separate thought. See 3.2.3 and 3.2.4.

3.2.3 Rule: To add a definition, a new definition number that is one number greater than the last relevant IEC definition number may be used with the addition of the “DV” suffix. If more than one subclause is included in the national difference, the subclauses should be numbered sequentially after the DV suffix. See the following example:

(IEC TEXT)

3.2.5 BARRIER: A part providing protection against direct contact from any usual direction of access.

(NATIONAL DIFFERENCE)

3.2.6DV D2 Add the following definition to Clause 3:

3.2.6DV.1 EXTRA-LOW VOLTAGE: A circuit that has an ac potential of not more than 30 V (42.4 peak), and power of 100 V·A or less; or 30 V dc supplied by a primary battery; or supplied by a Class 2 transformer; or supplied by a combination of a transformer or fixed impedance that, as a unit, complies with all the performance requirements for a Class 2 transformer.

3.2.6DV.2 A circuit that is derived from a circuit which exceeds 30 V by connecting resistance or impedance, or both, in series with the supply circuit to limit the voltage and current, is not considered to be an extra-low-voltage circuit.

3.2.4 Rule: To add a definition amid IEC definitions, the national difference may be placed within or at the end of the relevant IEC definition to which the national difference applies using an identifier consisting of a letter added to the relevant IEC definition number with the addition of the “DV” suffix. If more than one subclause is included in the national difference, the subclauses should be numbered sequentially after the DV suffix (see the example in 3.2.3). See the following example: