Catch the Z462 Train... Or Be Crushed By It
Dave Smith has been an Industrial Maintenance Electrician since 1975. He has taught maintenance, troubleshooting and safety courses to thousands of electricians in mines, mills, refineries, factories, plants, power stations and offshore platforms throughout North America and the Middle East. Dave is a hands-on guy and teache...
The on-board clients are now running into difficulties of implementation as the Z462 ‘rubber hits the road’. For example, most clients are using a two-class clothing system: Cat 2 daily wear and Cat 4 flash suits for specialty work. Cat 4 suits, however, are tremendously hot and bulky, with dark visors. Put on clumsy rubber and leather gloves and you have many excellent, dedicated electricians asking the obvious: Couldn’t this initiate an accident?
Imagine an electrician in an indoor substation with high-bay lighting wearing a Cat 4 suit and reaching into a 13.8 cubicle to turn off a control breaker. What was once a simple task with bare hands and safety glasses turns into an electrician struggling to see which of the breakers his gloved hands are touching; with his hood visor fogging up so he’s unable to see due to the lack of light; and visual distortion and faulty resolution from the transparent glues used in the manufacturing process.
Add to this a dirty or poorly cleaned visor with scratches impairing optical clarity and worsening glare. Looking closer, the electrician discovers that colour-coded wires look different in this environment. Given an extended amount of time, and you get oxygen deficiency, mental and physical fatigue, heat exhaustion and, potentially, heat stroke.
To avoid this situation, planning and forethought are essential before buying your PPE (personal protective equipment), and initial purchase cost should account for only a small part of the decision. For instance, Cat 2 coveralls with an 8.2-cal rating are a far more expensive purchase than Cat 2 coveralls with a 12.6-cal rating, even though they have a lower initial cost. Why?
An electrician working with an exposure to 8.3-cal equipment up to 12.6-cal would need to don Cat 4 clothing, whereas an electrician in 12.6-cal coveralls would just put on his gloves, faceshield, etc., and complete the task. This is a huge saving in time and annoyance.
All arc flash software categorizes any exposure above 40 calories as Extreme Danger, No Energized Work. We have clients with Cat 4 suits that are 50-cal suits whereas other clients have purchased 42-cal suits that are lighter.
This difference translates into huge differences in heat. Many clients, in an attempt to save perhaps $250, purchased flash suit hoods without built-in fans; 12 months, and many complaints later, they are buying the second hood with the fans.
If you’re ever in a hood with no fan, you’ll very quickly find the air feels stale, you are covered profusely with sweat running into your eyes, you cannot concentrate on the task and you have a significantly increased risk of initiating an accident. Even with the fan, any exertion over a period will raise core body temperature. One client had workers at height in a hot area with Cat 4 suits on and, by the time the job was finished, they had the fellows working 10 minutes and resting 50 to bring down their body temperatures—even with cold packs inside the suits.
Heat exhaustion becomes heat stroke and deadly at 40.5°C. There are many facilities with ambient temperatures above this range so every effort to reduce or dissipate trapped PPE heat is essential.
Every week I get asked, “Couldn’t this PPE initiate an accident?”, and my response combines many points. Yes, perhaps it could, so you need to make sure you are not relying on PPE alone. PPE is the final defence, so look at your engineering, purchasing and administrative controls; implement arc flash mitigation strategies in advance; find out-of-the-box solutions to deenergize equipment yet keep the loads energized, or delay the work until a shutdown and do it deenergized; perform a thorough Job Hazard Analysis, find multiple control barriers for every task step with a hazard (Poor light? Get temporary lighting!); write a Job Plan/SOP and follow it, and watch your safe work practices.
Remember that all these procedures and precautions are not optional; Z462 is now the standard in Canada for electrical safety and it mandates PPE. Arc flash accidents do not happen often, but when they do, unprotected workers get hurt—badly. Once you’re in a burn unit, you are in serious risk of getting an infection that could end your life.
Even if you survive, your life—as you knew it and enjoyed it—is over.
Implementing Z462 has hidden complexities, but our equipment is aging, our busses are getting bigger, maintenance is being extended and reduced, the old goats are retiring and taking their collective wisdom and experience with them, and leaving these tasks to the next generation.
Since getting flattened is not an option, you only have once choice: catch the Z462!
Until next time, be ready, be careful and be safe.
