CSA Z462 Workplace Electrical Safety Standard Updates

It’s important to note that this article is a technical interpretation by the author based on the published release of the CSA Z462 Workplace Electrical Safety Standard, 2021 Edition and is not an official interpretation from the CSA Group. The author takes no liability for the information presented, and the reader is advised to contact the CSA Group for any official interpretation.

Changes in the CSA Z462 Workplace Electrical Safety Standard are slowing down. That’s the good news. However, the 2021 edition includes a significant reorganization of content in Clause 4.1 and Clause 4.3, changes to existing Annexes, some new Annexes, and a significant change to the Clause 4.3.7.3.15 Arc Flash PPE Category Method of determining “additional protective measures” for a work task’s arc flash risk assessment. CSA Z462 2021 Edition is no longer 100% technically harmonized with the 2021 Edition of NFPA 70E Standard for Electrical Safety in the Workplace. The information in this article will help you better understand the CSA Z462 Workplace Electrical Safety Standard and the updates/changes in the 2021 edition. It will also provide information you can use to update an employer’s established electrical safety program.

Note: 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 Oct. 27, 2020, to review and approve any final amendments to the draft and a final vote occurred to the draft.

The CSA Z462 Workplace Electrical Safety Standard published its fifth edition on Jan. 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 in Canada. In other words, lives have been saved!

The first edition was published in January 2009. Over the first four editions, a significant evolution of the standard occurred. CSA Z462 moved from focusing on hazard identification and personal protective equipment (PPE) selection to a more mature standard aligned with occupational health and safety management system standards (e.g., CSA Z45001 and ISO 45001, CSA Z1002) to include a mandatory risk assessment procedure. The 2021 Edition of CSA Z462 is 100% work task risk-assessment based, including two unique risk assessments completed under the overall job’s risk assessment: Shock Risk Assessment and Arc-Flash Risk Assessment.

Technical harmonization of the core Clauses and Articles for the most part between CSA Z462 and NFPA 70E has been maintained in the first four editions. CSA Z462 includes additional Annexes that were not adopted into NFPA 70E — we see that again in the 2021 Edition of CSA Z462. In the 2021 Edition of CSA Z462, additional technical changes related to the arc flash PPE category are included. These changes are not published in NFPA 70E. The NFPA 70E 2021 Edition will include a significant new Article 360 [Safety-Related Requirements for Capacitors] and associated Annex R [Working with Capacitors] that is NOT included in the CSA Z462 2021 Edition.

The following are some of the highlighted changes and updates.

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 is referenced at 60VDC), and Work On (Notes).

The following definitions were deleted: Branch-Circuit Overcurrent Device, Switchgear, Arc-Resistant.

The following new definitions were 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 is included. This is a positive change to further clarify the core requirements of CSA Z462 aligned with regulatory requirements for hazard identification and risk assessment, and the specific framework/contents of an employer’s electrical safety program, and the elements that must be considered when completing a job’s risk assessment procedure. Content has been deleted altogether, updated, added, or relocated between Clauses. Significant Clause number changes will occur in Clause 4.1 and 4.3 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 proactively identify electrical hazards, eliminate exposure, assess and control associated 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. It is noted that CSA Z462 Clause 4.1 and 4.3 shall be referenced and applied 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, 30VAC will be retained but the threshold voltage for DC will be increased to 60VDC (reference the updated definition of Voltage with respect to 48VDC float voltage).

Reference will now be 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, and specifically Clause 4.3.2.2.4 [Normal Operating Condition] will be relocated to Clause 4.1 under Clause 4.1.7.8 risk assessment procedure and renamed to normal equipment condition. This is an appropriate update as the requirements of a normal equipment condition relate directly to risk assessment (i.e., likelihood of occurrence) and are not related to justification for energized electrical work.

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 relates to the type of training and now includes language in the Notes for the existing Clause 4.1.7.1.5 that now recognizes, “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.

In Clause 4.2, changes are included 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). With respect to Clause 4.2.5, a note is added regarding where a shared neutral conductor may still carry current. Some wording changes are included related to wording for a “permanently mounted absence of voltage tester.” A specific reference to UL 1436, Outlet Circuit Testers and Other Similar Indicating Devices, is added. With respect to Clause 4.2.6 [Temporary Protective Grounding Equipment], expanded content is added with respect to testing and inspection, and a new Annex T Temporary Protective Grounding is added with extensive additional information.

In Clause 4.3 as noted above, significant content is relocated to Clause 4.1 which enhances 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, insertion or removal of individual cells or multi-cell units of a battery system in an open rack,” which was a repeated work task. A new work task is 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.  A wording change to the “Removal of battery conductive intercell connector covers” to “Insertion or removal of connector covers or battery intercell connector(s).” The arc-resistant switchgear work task description is updated.

Minor updates to CSA Z462 Table 3 with respect to the 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 are included.

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. It is noted that arc flash suits are available with an ATPV of 140 cal/cm².

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 existing Table 6A arc-flash PPE categories for alternating current (AC) systems electrical equipment parameters were used with the new IEEE 1584 2018 Edition formulas and a new arc flash PPE Category 5, minimum 75 cal/cm² is added for 600V class switchgear. In addition, the arc-resistant electrical equipment rows 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)] adds the new arc flash PPE Category 5 and quotes minimum 75 cal/cm² ATPV arc-flash PPE.

A new alternate table to Table 6A, Table V.1 is also added in a new Annex V [Arc-Flash PPE Categories] that will be a normative Annex. 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 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 “240VAC single phase,” indicating an abnormal arcing fault is sustainable for 240VAC single-phase electrical equipment.

Official clarification can be requested from the CSA Group for the 2021 Edition of CSA Z462 with respect to the addition of 240VAC single-phase electrical equipment in the new Table V.1, as capable of sustaining an abnormal arcing fault condition and causing an arc flash to occur on 120/240VAC panelboards.

Clause 5 — safety-related maintenance requirements

A general rewrite of Clause 5 is included. Much of the existing content is retained, 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 the 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.

Annexes

In the CSA Z462 2021 Edition, several existing Annexes are updated, and the provision of several new Annexes to provide additional explanatory and supplemental information to reference regarding the core Clause content of CSA Z462 are included.

Annex A [Updated] ― This Annex is updated to reference CSA Z45001. A new cross-reference table is provided 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 and a reference only (no detailed formulas content from IEEE 1584 is included) to the new updated IEEE 1584 2018 Edition added.

Annex I [Updated] Sample Job Briefing and Planning Checklist ― a new Figure I.2 sample job planning checklist is added.

Annex J [Updated] Sample Energized Electrical Work Permit and Flow Chart ― Figure J.2 is amended to update the applicability of the permit for 30VAC or now 60VDC.

Annex K [Updated] General Categories of Electrical Hazards ― a complete rewrite related to arc blast is included, 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 more than 10 years. This newly 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.

Annex O [Updated] Safety-Related Design ― has been significantly updated with changes and editions.

Annex P [NEW] Electrical Switching and Isolation ― has been 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 as an alternative method to give arc flash hazard information to Qualified Persons other than the application of arc flash & shock equipment labels.

Annex T [NEW] Temporary Protective Grounding ― provides additional application information further than the content of CSA Z462, Clause 4.2.6.

Annex V [NEW] Arc flash PPE Categories ― this is a normative Annex providing an alternate table to Table 6A. An instructional flow chart is included [Arc-Flash PPE Categories Selection Flow Chart] and then Table V.1.

In closing, the CSA Z462 Workplace Electrical Safety Standard has made a significantly positive impact in Canada since 2009 regarding worker safety related to energized electrical work. Many employers reference CSA Z462 when developing their electrical safety programs and as a basis of due diligence to OH&S regulations. They also reference it when 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 or reduce risk to as low as reasonably practicable.

Terry Becker, P.Eng. is a senior member of IEEE, an electrical safety specialist, and a management consultant with TW Becker Electrical Safety Consulting in Calgary, Alberta, Canada. He can be reached at [email protected].