There has been much emphasis in Canada recently on looking at electrical maintenance from two perspectives: safety and production. Many times, these go hand in hand. The standards committees in Canada are paying specific attention to devices that — when not maintained properly — can have an adverse effect on the electrical safety of workers. These include the most commonly used devices for switching the power system and protection devices that need to operate quickly during faults.
To illustrate what the industry is contemplating, let’s look at two examples of apparatus in a power system: buried underground cable and a low-voltage removable power circuit breaker. The safety and production considerations are quite contrasting.
- A buried underground cable failure would have low probability of creating a dangerous situation for a worker but could have severe ramifications to production or extended downtime. There is always a slim chance the worker is in close proximity to the failure point at one of the exposed ends; if the protection does not operate, the worker could be exposed to some energy. This would be more of a protection failure, and the probability of the worker being in close proximity at the exact time of failure is very low. However, failure of an underground cable could result in lengthy outage time and a very adverse effect on production, particularly if the fault must be located, exposed, and repaired. Days or even weeks of lost production could result depending on how the system is designed.
- In contrast, a low-voltage circuit breaker failure due to lack of maintenance has numerous safety ramifications to the worker directly. A trip unit malfunction could produce larger than expected arc flash values due to extended trip times, could allow ground fault currents to flow, and could leave extended short-circuit currents without instantaneous tripping. A low-voltage breaker mechanical failure can be hazardous to the worker during racking or operating tasks when the worker is directly engaging with the unit. Many times, these mechanical failures go unnoticed on breakers that do not get exercised regularly, and the worker is at risk unknowingly. From a production perspective, most facilities would have a spare low-voltage breaker and would rack it in with limited interruption to production.
Clearly, there are very different maintenance objectives.
Therefore, it is critical to identify equipment within a maintenance program from a mindset of the different objectives for safety and production. The standards committees in Canada are particularly stressing the safety perspective.
CSA Z463, Maintenance of Electrical Systems and CSA Z462, Workplace Electrical Safety both address electrical maintenance. CSA Z462 places maintenance as a critical part of any risk assessment and provides safety-related maintenance requirements in Clause 5. CSA Z463 requires equipment that has adverse effects on workers’ safety when not maintained to be identified and a maintenance program to be built around that.
CSA Z463
CSA Z463 is mid-cycle, and the technical committee is just reorganizing to get ready for the next update in 2023. Since its release in 2018, the standard has been a popular seller for CSA, as many companies are using it as the backbone of their electrical maintenance program. This document requires identification of equipment that, when unmaintained, could have safety ramifications to workers. These identified devices are then required to be part of the electrical maintenance program. CSA Z463 asks users to pay particular attention to the items in the power system that can adversely affect personnel safety and ensure that a maintenance program is in place for those items. The standard indicates which tests and inspections must be performed, but it does not mandate the particular maintenance strategy, as each power system has different operating characteristics. The standard does mandate that equipment that is critical to worker safety must be part of the electrical maintenance program and not “run to fail.”
CSA Z462
CSA Z462 is in a revision cycle in line with NFPA 70E. Meetings will be held November 19–20, 2019, in Toronto to review changes to NFPA 70E and to update the Canadian standard. It should be noted that the copyright agreement between NFPA and CSA is not in place at this time, so future revisions to 70E will not be input word for word directly into Z462. In the same manner, changes to the new edition of Z462 will not be reflected in 70E. These copyright issues are a challenge for companies working on both sides of the Canada–US border. However, the goal moving forward is to remain technically harmonized as much as possible.
Of specific note in the Z462 safety standard is that Clause 5, safety related maintenance requirements, will be revamped as follows:
- Consolidate items that are repeated in various clauses.
- Remove some irrelevant material.
- Add more about maintenance of equipment that directly affects worker safety.
- Reorganize the section.
- Align with CSA Standard Z463, Maintenance of Electrical Systems.
The objective for this revamp is to focus on maintenance program requirements that directly support worker safety.
Conclusion
We continue to work in Canada to build on the understanding that electrical maintenance has objectives for safety and production. The Canadian safety standards are committed to ensuring workers can better understand the condition of equipment and how that can determine work tasks, risk mitigation, and selection of PPE.
Kerry Heid is an Executive Consultant with Shermco Industries Canada Inc. After beginning his career with Westinghouse Service, Kerry started the Magna Electric Corporation (MEC) office in Regina in 1996 and became President of the company in 2001. The company grew to over 1,000 employees and earned many prestigious awards as one of Canada’s 50 Best Managed Companies and Canada’s Top 100 Employers. MEC was acquired by Shermco Industries in December 2013. Kerry is a NETA past-President, served on NETA’s Board of Directors for over 10 years, won NETA’s Outstanding Achievement Award in 2010, and is a NETA Certified Level 4 Test Technician. He chairs the CSA Z463 Maintenance of Electrical Systems Technical Committee and has been on the CSA Z462 Workplace Electrical Safety Technical Committee since its inception in 2006. Kerry received CSA’s Award of Merit in 2019.