Meeting the New CSA Z462 Standard
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...
First, a little background: the Canadian Standards Association creates standards for Canadians. Having this national body for writing standards means individual provinces/territories need not have their own standards-writing bodies. CSA writes standards with input from all Canadians, then makes them publicly available on a cost recovery basis.
CSA has no legislative powers; its standards are voluntary. Province and territories (and companies) choose whether they wish to adopt them. For instance, it has been standard practice for decades that each jurisdiction adopt the Canadian Electrical Code (C22.1-06, Part I, Safety Standard for Electrical Installations). Other standards—especially new ones—are not automatically adopted.
Standard on workplace electrical safety seeks adoption!
Z462 is a new standard, meaning it will take years (if ever) before jurisdictions begin adopting it. Herein lay the problem: many people believe that, unless Z462 is officially adopted, no one has to follow it.
This is a major misconception: in numerous Canadian jurisdictions, safety legislation states employers must protect their workers from arc flash or flashover. The wording may change, but the legislative intent does not. This is referred to as a specific duty clause. When your company operates in a jurisdiction where this wording is found in the legislation, then Z462 is not optional. The final defence for protecting your workers from arc flash or flashover is PPE (personal protective equipment), and the only way to determine appropriate PPE is by following Z462.
There are two methods for determining PPE within Z462. The first, Clause 4.3.3.3.2, describes “Method 1: Selection based on incident energy analysis”, which is also known as conducting an arc flash hazard analysis. This has at least six parts to it:
1. Conduct a short-circuit study
2. Conduct a co-ordination study
3. Take the results from these and conduct the arc flash hazard analysis
4. Put labels on all of your equipment describing the arc flash hazard at that equipment
5. Purchase the PPE that will protect your workers at that equipment
6. Train your workers to understand the labels and correct PPE use.
Looks simple, right? Wrong. $10,000 doesn’t go very far, and one northern mine is looking at a $2.5-million investment. A major city transit system figures it might take about five years to complete its study.
A less expensive—though not as precise—method is to have your workers follow the ‘Task Tables’. Clause 4.3.3.3.3 describes “Method 2: Selection based on hazard/risk categories”, which refers you to Clause 4.3.7.3.9 “Selection of personal protective equipment for various tasks”.
These tasks are listed in Table 4 “Hazard/risk category classifications and use of rubber insulating gloves and insulated and insulating hand tools”. Further complicating the mix is that the Task Tables are limited to systems with short-circuit and protective device parameters that are known to be under a certain limit. When the system is beyond that limit, Clause 4.3.7.3.9 requires an incident energy analysis.
Until then, Table 4 lists common tasks performed on electrical equipment. For example, operating a 120V, 15A breaker is a Hazard/Risk Category 0. This seems simple enough until you learn that Category 0 requires cotton clothing—no polyester blends, which are outside the standard. For example:
A worker goes to reset a breaker that has tripped due to the poor use of a chop saw, and the panel flashes during reset.
If his overalls ignite, he’s off to the burn centre; you’re outside the standard, and authorities will conclude you haven’t met the specific duty clause. Good luck in court.
And even if your jurisdiction does not yet have a specific duty clause relating to arc flash or flashover, it is guaranteed to have a general duty clause, which uses wording like “The employer shall protect workers from all recognized hazards”. Arc flash and flashover are now very well-recognized hazards and, in the example above, you would still find yourself in court.
An electrician is voltage testing a 600V disconnect. He must be protected to HRC 2*.
If you do not know what this means, you’re outside the standard. You’d better hope a meter lead does not slip off a lug, or else you’ll find yourself in court again.
The bottom line is you have to protect your workers, and the only way to protect them from arc flash or flashover is by adopting CSA Z462 as your minimum standard. It is the best risk management you’ll ever employ to protect your electrical and other workers. Should you choose not to adopt it, then you may as well cancel that fire insurance you have on your house... you’re less likely to experience a house fire than an industrial accident.
Until next time, be ready, be careful and be safe.
