CSA Group CSA Z462:24 National Standard of Canada Workplace electrical safety

Preface

This is the sixth edition of CSA Z462, Workplace electrical safety. It supersedes the previous editions published in 2021, 2018, 2015, 2012, and 2008.

This Standard is based on NFPA 70E, Standard for Electrical Safety for the Workplace, and has been harmonized with Parts I, II, and III of the Canadian Electrical Code; CSA Z460, Control of hazardous energy — Lockout and other methods; and CSA M421, Use of electricity in mines. This revised edition of CSA Z462 has been developed by CSA Group from the original edition as promulgated by the National Fire Protection Association (NFPA). In addition to its initial source, it includes significant revisions by CSA Group. This Standard is fully the responsibility of CSA Group. The NFPA, holder of the copyright in this edition, takes no responsibility for any portion thereof.

This Standard specifies requirements for and provides guidance on safety management systems, safe work procedures, and selection of personal protective equipment and other safety devices for persons exposed to hazards associated with energized electrical equipment. In addition, this Standard sets out criteria for the identification and training of qualified electrical workers and for determination of hazardous work to be performed only by those qualified individuals.

By permission of the NFPA, many of the clauses, tables, and figures in this Standard have been copied from NFPA 70E. CSA Group wishes to thank the NFPA for its support throughout the development of this Standard.

The following is an overview of the major revisions to the 2024 edition:

a) the definition of “arc rating” has been modified to include an arc rating limit for faceshields

(Clause 3);

b) definitions for “laser”, “radiation, ionizing”, “radiation, non-ionizing”, and “temporary protective

grounding equipment” have been added (Clause 3);

c) the requirements related to an electrically safe work condition were reorganized into three clauses

(Clauses 4.1.6.1, 4.1.6.2, and 4.1.6.3);

d) the exception to the requirement to establish an electrically safe work condition (Clause 4.1.6.3)was revised to a single exception, i.e., when it is “not practicable” to do so, to align with Canadianoccupational health and safety regulations;

e) added that the requirement to verify the absence of voltage must be done “at each point of work”

(Clause 4.2.5);

f) added several items to the list of activities exempted from requiring an energized electrical workpermit in Clause 4.3.2.3;

g) Table 2, which can be used to estimate the likelihood of occurrence of an arc flash incident for acand dc systems, was relocated to Annex F as Table F.2;

h) the term “leather protectors” (as applied to gloves worn over rubber insulated gloves) has beenchanged to “protectors” throughout this Standard (Clauses 3, 4.3.5.6.2, 4.3.7.2.1, 4.3.7.3.7,4.3.7.3.10, Q.4, and R.3.3, and Tables H.1 and H.2) to permit the use of protector glovesconstructed of leather or materials other than leather, and a definition of “protectors” has beenadded to Clause 3;

i) the arc flash PPE category method requirements (Clause 4.3.7.3.15 and Tables 6A and 6B) wererelocated to follow Table V.1 in Annex V as Tables V.2 and V.3, respectively, and the method wasrevised and retitled as the “arc flash PPE selection table method”;

j) a new figure was added to Annex V to provide guidance for the use of Table V.1, and severalentries were added to Table V.1 to increase granularity;

k) the arc flash personal protective equipment, Table 6C, has been deleted, all references to “arc flashPPE category” have been replaced with “arc flash PPE minimum arc rating”, and the arc flash PPEcategory numbers of 1, 2, 3, 4, and 5 have been replaced in Tables V.1, V.2, and V.3 with aminimum arc rating of 4, 8, 25, 40, and 75 cal/cm2, respectively;

l) the determination regarding whether a circuit can be safely re-energized after it has been de[1]energized by the automatic operation of a circuit protective device shall now be done by aqualified person or persons (Clause 4.3.8.13);

m) energy thresholds for safety requirements related to batteries and battery rooms or batteryenclosures (Clauses 6.3.1 and 6.3.2) were revised;

n) information on battery risk assessment (Clause 6.3.2.2) was added to Annex F;

o) added capacitor stored energy thresholds for safety-related work practices for use of lasers

(Clause 6.4.2.1);

p) added several categories of power electronic equipment and the associated electrical hazardthresholds (Clause 6.5);

q) added new safety-related requirements for capacitors (Clause 6.7) and new information onworking with capacitors (Annex W), and added the following terms used exclusively in Clause 6.7 to Clause 3 and identified these terms by the parenthetical phrase (“as applied to capacitors”):

“boundary, hearing protection”, “boundary, lung protection”, “charge transfer”, “dielectric

absorption”, “ground stick”, “grounding, hard”, “grounding, soft”, “hazard, arc blast”, “protector”,

“resistor, bleeder”, “time constant”, and “time, discharge”;

r) added guidance on assessing the condition of maintenance of electrical equipment and systems

(Clause B.5); and

s) reorganized the types of electrical hazards in Annex K into two categories of shock and arc flashand added guidance regarding electrical hazards and associated injuries, including “electric shocksequela”.

This Standard was prepared by the Technical Committee on Workplace Electrical Safety, under the jurisdiction of the Strategic Steering Committee on Occupational Health and Safety, and has been formally approved by the Technical Committee.

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.

Notes:

1) Use of the singular does not exclude the plural (and vice versa) when the sense allows.

2) 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.

3) This Standard was developed by consensus, which is defined by CSA Policy governing standardization — Code of good practice for standardization as “substantial agreement. Consensus implies much more than a simple majority, but not necessarily unanimity”. It is consistent with this definition that a member may be included in the Technical Committee list and yet not be in full agreement with all clauses of this Standard.

4) To submit a request for interpretation of this Standard, please send the following information to [email protected] and include “Request for interpretation” in the subject line:

a) define the problem, making reference to the specific clause, and, where appropriate, include an illustrative sketch;

b) provide an explanation of circumstances surrounding the actual field condition; and

c) where possible, phrase the request in such a way that a specific “yes” or “no” answer will address the issue.

Committee interpretations are processed in accordance with the CSA Directives and guidelines governing standardization and are available on the Current Standards Activities page at standardsactivities.csagroup.org.

5) This Standard is subject to review within five years from the date of publication. Suggestions for its improvement will be referred to the appropriate committee. To submit a proposal for change, please send the following information to [email protected] and include “Proposal for change” in the subject line:

a) Standard designation (number);

b) relevant clause, table, and/or figure number;

c) wording of the proposed change; and

d) rationale for the change.

1 Scope

1.1 General

This Standard specifies requirements for workplace electrical safety necessary for the practical safeguarding of workers during activities such as the installation, removal, inspection, operation, maintenance, and demolition of electric conductors and electric equipment, as well as work in proximity of energized electrical equipment.

1.2 Application

While it can be applied by organizations of any type or size, this Standard does not cover

a) installations in ships, watercraft other than floating buildings, railway rolling stock, aircraft, and automotive vehicles other than mobile homes and recreational vehicles;

b) installations of railways for the generation, transformation, transmission, or distribution of power used exclusively for operation of rolling stock or installations used exclusively for signalling and communications;

c) installations of communications equipment under the exclusive control of communications utilities located outdoors or in building spaces used exclusively for such installations; and

d) installations under the exclusive control of an electric utility when such installations

i) consist of service drops or service laterals, and associated metering;

ii) are located in legally established easements or rights-of-way designated or recognized by public service commissions, utility commissions, or other regulatory agencies having jurisdiction for such installations; or

iii) are on property owned or leased by the electric utility for communications or for metering, generation, control, transformation, transmission, or distribution of electric energy.

1.3 Suitability

It is the responsibility of the users of this Standard to judge its suitability for their particular purpose

(see Note 2 to the Preface).

1.4 Use with related standards and regulations

This Standard is intended for use with Parts I, II, and III of the Canadian Electrical Code and other related Canadian workplace electrical safety standards (e.g., CSA M421 and CSA Z460), and should be used with such standards. In addition, users of this Standard should always refer to provincial, territorial, and federal safety regulations that have jurisdiction over their work facility, contract job site, or profession.

1.5 Organization of this Standard

The requirements of this Standard are organized in three main clauses (Clauses 4 to 6) and one Annex (Annex V), as shown in Figure 1. Annexes A to U, W, and X do not specify requirements and are included for information only.

1.6 Measurements

The values given in SI units are the units of record for the purposes of this Standard. The values given in parentheses are for information and comparison only.

1.7 Terminology

In this Standard, “shall” is used to express a requirement, i.e., a provision that the user is obliged to satisfy in order to comply with the Standard; “should” is used to express a recommendation or that which is advised but not required; and “may” is used to express an option or that which is permissible within the limits of the Standard.

Notes accompanying clauses do not include requirements or alternative requirements; the purpose of a note accompanying a clause is to separate from the text explanatory or informative material.

Notes to tables and figures are considered part of the table or figure and may be written as requirements.

Annexes are designated normative (mandatory) or informative (non-mandatory) to define their application.

Figure 1

Organization of this Standard

(See Clause 1.5.)