Changes in the CSA Z462, Workplace electrical safety Standard are slowing down. Good news! That said, the 2021 Edition includes significant reorganization of content in Clause 4.1 and Clause 4.3, changes to existing annexes and some new annexes, and a significant change to the Arc Flash PPE Category Method of determining “additional protective measures” for a work task’s arc flash risk assessment. CSA Z462, 2021 Edition IS NOT 100% technically harmonized with the 2021 Edition of NFPA 70E.
The following information is provided for the benefit of the reader in understanding the CSA Z462, Workplace electrical safety Standard and the updates/changes to the 2021 Edition, as well as for the employer in order to update an established electrical safety program. A compliant electrical safety program’s internal electrical safety audit would identify the need to update the electrical safety program whenever a new edition of CSA Z462 publishes.
Note: The information provided in this article is the technical interpretation of the author and is not an official interpretation from the CSA Group. The author takes no liability for the information presented. The information presented is based on the published CSA Z462, 2021 Edition. This article does not include all changes or updates.
CSA Z462, 5th EDITION
CSA Z462, Workplace electrical safety Standard published its fifth edition on January 5, 2021. Since its inception in 2006 following CSA and NFPA executing a memorandum of understanding (MOU) to harmonize standards for North America, CSA Z462 has had a positive impact on electrical safety and the identification and effective management of arc flash and shock hazards. Lives have been saved!
The first edition published in January 2009. Over the first four editions, significant evolution of the standard has occurred. CSA Z462 moved from focusing on hazard identification and PPE selection to a more mature standard aligned with occupational health and safety management system standards (e.g. CSA Z45001, ISO 45001) to include a mandatory risk assessment procedure. In the 2018 and 2021 Editions, CSA Z462 is 100% job and discrete work-task and risk-assessment based, including two unique risk assessments completed under the overall job’s risk assessment specific to the work task(s) that will be performed: the shock risk assessment and arc flash risk assessment.
Technical harmonization of the core clauses and articles between CSA Z462 and NFPA 70E has been maintained for the most part in the first four editions. CSA Z462 includes additional annexes that were not adopted into NFPA 70E. This has occurred again in CSA Z462, 2021 Edition.
The 2021 Edition of CSA Z462 includes additional changes of a technical nature related to the Arc Flash PPE Category Method that are not published in NFPA 70E. NFPA 70E, 2021 Edition includes a significant new Article 360 Safety-Related Requirements for Capacitors and an associated Annex R Working With Capacitors that are NOT included in the CSA Z462, 2021 Edition.
The CSA Z462, 2021 Edition public review draft closed July 29, 2020. You are encouraged in future revision cycles to submit public comments and influence the direction of the CSA Z462 standard. The CSA Z462 Technical Committee met on October 27, 2020, to review and approve final amendments to the draft, and a final vote occurred to the draft. The 2021 Edition of CSA Z462 as noted above published on January 5, 2021.
CLAUSES
The following changes and updates are noted. Not all changes are included in this article.
Clause 3 Definitions
The following definitions have been altered, or updated: Accessible, Balaclava (sock hood), Barrier, Equipment, Arc-Resistant, Fault Current, Available (Note), Receptacle, Shock Hazard, Voltage Nominal (note on float voltage for DC to change the threshold for applicability of CSA Z462 to 60 VDC from 30 VDC), and Work On (Notes). To clarify, if the voltage is 30 VAC or less or 60 VDC or less, CSA Z462’s requirements do not apply.
The following definitions are deleted: Branch-Circuit Overcurrent Device, Switchgear, Arc-Resistant.
The following new definitions are added: Normal Operation, Policy, Procedure, Process, and Program.
Clause 4 Safety-Related Work Practices
A substantial reorganization of content from Clause 4.1 and Clause 4.3 has occurred. This is a positive change to further clarify the framework/contents of an employer’s electrical safety program and the elements that need to be considered when completing a work task’s risk assessment procedure. Content is deleted altogether, updated, or relocated between clauses. Significant clause number changes will occur with this realignment of content.
Clause 4.1 now identifies that an employer shall create and document an “Electrical Safety Policy” that affirms the organization’s commitment to identify electrical hazards, eliminate exposure, or assessment and control risks, and as a priority, establish an electrically safe work condition. This policy shall be documented in the employer’s electrical safety program. Clause 4.1 will now include a new clause with a general requirement that an electrically safe work condition shall be established as identified in Clause 4.2. Practices as identified in CSA Z462 Clause 4.1, and Clause 4.3 shall be used if an electrically safe work condition cannot be established.
Justification statements for energized electrical work are relocated from Clause 4.3 to Clause 4.1. With respect to the applicable voltage level that CSA Z462 applies to in the 2021 Edition, 30 VAC will be retained, but the threshold voltage for DC will be increased to 60 VDC.
Reference is now made to CSA Z45001 instead of CSA Z1000 as the CSA Group adopted ISO 45001 with respect to occupational health and safety management systems. Annex A in turn has been completely updated with respect to the comparison table of how CSA Z462 aligns with the requirements of CSA Z45001.
Some updated content will be added to the risk assessment procedure clause, specifically Clause 4.3.2.2.4 Normal Operating Condition will be relocated to Clause 4.1 under Risk Assessment Procedure and is renamed Normal Equipment Conditions. A new definition of Normal Operation is added. This is an appropriate update as the requirements of a normal equipment condition relate directly to risk assessment (e.g. likelihood of occurrence) and are not related to justification for energized electrical work. This aligns with the arc flash risk assessment CSA Z462 Table 2.
Additionally, in Clause 4.1.6.9 from the 2018 Edition (this clause will be renumbered), new Annex I content will be added providing an example of a job safety planning checklist. Updated Clause 4.1 content will be included for Lockout Program and Procedures.
A significant change in the 2021 Edition related to type of training includes the addition of language in the Notes for the existing Clause 4.1.7.1.5, which now recognizes that classroom training can include “interactive electronic or interactive web-based training.”
Some additional content is included in existing Clause 4.1.10 Portable (cord-and-plug-connected) Electrical Equipment related to maintenance, handling, and storage.
Clause 4.2 includes two changes to the existing Clause 4.2.5 Process for Establishing and Verifying an Electrically Safe Work Condition and Clause 4.2.6 Temporary Protective Grounding Equipment.
A note is added to Clause 4.2.5 with respect to where a shared neutral conductor may still carry current. Some wording changes are included for a “permanently mounted absence of voltage tester.” A specific reference to UL 1436, Outlet Circuit Testers and Other Similar Indicating Devices is added.
In Clause 4.2.6 Temporary Protective Grounding Equipment, expanded content is added with respect to testing and inspection, and a new Annex T is added with extensive additional information.
In Clause 4.3 as noted above, significant content is relocated to Clause 4.1, which does enhance the flow of content in CSA Z462 and what an employer’s electrical safety program shall include for content.
In Clause 4.3 some additional content modifications are included with respect to describing the “estimate of likelihood and severity” for a work task’s shock risk assessment. CSA Z462 Table 2 Estimate of the Likelihood of Occurrence of an Arc Flash Incident for AC and DC Systems includes the deletion of the work task: “For DC systems, maintenance on a single cell of a battery system or multi-cell units in an open rack”; this duplicated “Maintenance and testing on individual battery cells or individual multi-cell units in an open rack.” A new work task was added: “Operation of a circuit breaker or switch the first time after installation or completion of work or maintenance in the equipment” for any equipment condition. The wording of “Removal or battery conductive intercell connector covers” changed to “Insertion or removal of connector covers or battery intercell connector(s).” The arc resistant switchgear work task description is updated and renamed “Arc-resistant equipment.”
Some minor updates are included to Table 3 with respect to addition of “high-visibility apparel” and clarifying in notes that outerwear arc-rated clothing worn over selected arc-rated PPE is not considered as part of the required ATPV for the anticipated incident energy exposure.
In Clause 4.3.7.3 Personal Protective Equipment, new content is added to the note providing risk control method options to consider when the incident energy exceeds the ATPV of commercially available arc flash PPE to manage risk (e.g. Oberon Company 140 cal/cm2 ATPV).
In Clause 4.3.7.3.7 Hand and Arc Protection, a new Table 4A Maximum Use Voltage for Rubber Insulating Gloves is added to identify Class number and maximum AC and DC use voltages. This table is taken from ASTM F496, Standard Specification for In-Service Care of Insulating Gloves and Sleeves, Table 1 Voltage Requirements.
The most significant change in CSA Z462, 2021 Edition relates to Clause 4.3.7.3.15 Arc Flash PPE Category Method. The existing Table 6A Electrical Equipment Parameters were used (with other selected IEEE 1584 parameters) with the new IEEE 1584, 2018 Edition formulas. A new arc flash PPE category 5, minimum 75 cal/cm2, will be added for 600-V-class switchgear. Also, the arc resistant electrical equipment rows will clarify that the arc flash PPE category is N/A when doors are closed and secured and the available fault current does not exceed the arc-resistant rating of the electrical equipment. Table 6C Personal Protective Equipment (PPE) will add the new arc flash PPE category 5 and quote minimum 75 cal/cm2 ATPV arc flash PPE (e.g. Arc Flash Suit).
The most significant change is a new alternate table to Table 6A. Table V.1 is added in a newnormative Annex V Arc Flash PPE Categories. The existing Table 6A Arc-Flash PPE Categories for Alternating Current (AC) Systems has not been deleted and either Table 6A or Table V.1 can be used.
Included in the new Annex V is Figure V.1, Table V.1 Arc-Flash PPE Categories Selection flow chart, which is provided as a guide to the use of the alternate Table V.1. Table V.1 was added in an effort to simplify the information gathering required to use the arc flash PPE category method.
Of significance, this new Table V.1 includes electrical equipment that is “240 VAC single-phase” indicating abnormal arcing fault probability is sustainable for 240 VAC single-phase electrical equipment. Official clarification from the CSA Group with respect to the addition of 240 VAC single-phase electrical equipment in the new Table V.1 can be requested to get specific technical clarification on why 240 VAC single-phase electrical equipment is capable of sustaining an abnormal arcing fault condition and causing an arc flash to occur on 120/240 VAC panelboards.
Clause 5 Safety-Related Maintenance Requirements
A general rewrite of Clause 5 is included in CSA Z462, 2021 Edition. A lot of the existing content is retained but will be removed and the clause numbering is completely updated. A new clause is added with respect to the owner of the electrical equipment establishing, implementing, and maintaining a documented maintenance program for electrical equipment and references CSA Z463, Maintenance of electrical equipment Standard.
The updates, revisions, and additions to Clause 5 improve its readability and the interpretation of the information presented. It is recommended that the CSA Z463, Maintenance of Systems Standard be purchased from the CSA Group and referenced with respect to reviewing electrical equipment maintenance requirements.
ANNEXES
In CSA Z462, 2021 Edition, several existing annexes are updated and several new annexes are included to provide additional explanatory and supplemental information to reference with respect to the core clause content of CSA Z462.
Annex A Updated. References CSA Z45001 and provides a new cross-reference table specific to CSA Z462 and the CSA Z45001 occupational health and safety management system intent or objective.
Annex D Updated. The existing IEEE 1584, 2002 Edition content is deleted (no detailed formula content from IEEE 1584 is included). References added to only the new updated IEEE 1584, 2018 Edition.
Annex I Updated. Added a sample job briefing and planning checklist and a new Figure I.2 Sample Job Planning Checklist.
Annex J Updated. Sample energized electrical work permit and Figure J.2 Energized Electrical Work Permit Flow Chart amended to update the applicability of the permit for 30 VAC or now 60 VDC.
Annex K Updated. Includes a complete rewrite of the general categories of electrical hazards as related to arc blast indicating that arc blast pressure is not as significant as it has been presented in the past. Note I have quoted that 40 cal/cm2 of incident energy is not a stop point for energized work, which has been a true statement for over 10 years. This updated published information in Annex K will now provide additional substantiation for this. Energized work tasks can be performed up to 140 cal/cm2 of incident energy, as an arc flash suit is available from Oberon Company with an ATPV of 140 cal/cm2.
Annex O Updated. Safety-related design has been significantly updated with changes and additions.
Annex P New. Electrical switching and isolation is added to provide general information for low- or high-voltage complex switching and isolation including a new Figure P.2 Example Switching Order form.
Annex Q Updated. Arc flash and shock warning equipment labels includes minor wording updates and updated example equipment labels to correct the orange color used to properly align with ANSI Z535. A specific note is now included that states electrical hazard information for supervised industrial installations can be provided through alternative methods other than the application of equipment labels.
Annex T New. Temporary Protective Grounding is added to provide application information further in addition to the content of CSA Z462, Clause 4.2.6.
Annex V New. Arc flash PPE categories added. This is a normative annex providing an alternate table to Table 6A. An instructional flow chart is included: Arc-Flash PPE Categories Selection and then Table V.1.
SUMMARY
Since 2009, CSA Z462, Workplace electrical safety Standard has made a significantly positive impact in Canada to worker safety related to energized electrical work. Many employers are referencing CSA Z462 when developing their electrical safety programs and determining the hierarchy or risk-control methods to apply to work tasks to eliminate exposure to arc flash and shock for qualified electrical workers and task qualified workers to reduce risk as low as reasonably practicable.
This article is not an official interpretation from the CSA Group and is based on the interpretation of the author of this article. You are advised to contact the CSA Group for any official interpretation. If you would like to discuss this article and the information presented, please contact me at terry.becker@twbesc.ca (www.twbesc.ca) or 1-587-433-3777.
Terry Becker, P.Eng., CESCP, IEEE Senior Member, is an Electrical Safety Specialist and Management Consultant. He is the first past Vice-Chair of CSA Z462, Workplace electrical safety Standard Technical Committee and currently a Voting Member and Clause 4.1 and Annexes Working Group Leader. Terry is also a Voting Member on CSA Z463, Maintenance of electrical systems Standard and a Voting Member of IEEE Std. 1584, Guide for Performing for Arc-Flash Hazard Calculations. He has presented at conferences and workshops on electrical safety in Canada, the United States, India, and Australia, and is a Professional Engineer in the Provinces of British Columbia, Alberta, Saskatchewan, Manitoba, and Ontario.