Arc Flash Blasts, why is the industry so slow to make improvments?

[Breakerboy]

NFPA 70E's Arc Flash calcs were shown to be faulty 2-3 years ago by IEEE. Since they left out the times associcated with fault detection relays, trip relays and any other vital equipment required to clear a fault. Now that we know we have much higher arc flash energy than the original calcs, why aren't we taking this more serious. I for one became a believer when I saw some test video with data, a real arc flash blast caught on tape and then found out that we have 5-10 arc flash blasts each day in the US alone (OSHA reporting).

We as an industry have done a poor job sharing operating experience when it comes to sharing incidents that we have experienced and maybe that feeds into the "it can't happen to me" syndrome. If we knew about all of the problems and what gear was involved and what PPE was being used and still problems occur, we might act differently. Our plant is installing remote breaker racking on all 90 of our 13.8kv and 4.16kv breakers so we can move our operators and electricians out of the blast area. We will also be installing remote breaker racking on Load Centers since their energy levels are in the 30cal/cm2 range. No flash suit made can protect you from the concusive blast above 40 cal/cm2. By the way, before I get buried in the remote racking nah-sayers, we found a system that wont' allow the breaker to rack up or down if it becomes out of level, or if it becomes bound up or if shutters fail to open. I know many of the systems on the market will allow you to continue to rack a breaker even if one of those conditions exist. It is important that we not cause more arc flash blasts simply by installing remote racking systems that don't protect the equipment as well as the workers.

So what are the excuses? What are we willing to bet against? What odds will you accept, one life, maybe two?! We lost 3 men in one incident several years ago, and we aren't going to tell any more widows that we didn't know, now you do too!

 

[rbulsara]

Breakerboy:

Many reasons. At the end of the day its all about what we know, what can we do and what can we afford. Also we live and learn. Just because we may know about a risk and even a probable protection, that does not mean that we can afford the protection all the time and everywhere.

It is no different than other aspects of our lives. For example, take cars. Are they 100% safe today? No. Are they safer than 30 years ago? Yes. Do we know one can get killed in car accident on a highway? Yes. Do you still drive the car on a Highway? Yes. Are we trying to improve car safety? Yes.

Does every one buy the fully loaded car with antilock brakes, proximity sensors and air bags for all seats? No. Are they available? Yes.

The same goes for the arc flash. We just learning as to how to even estimate arc flash energy. As we refine our knowledge, our codes, standards and work practices will improve. One thing is sure that we will not just STOP having electrical equipment around until they are 100% safe. They never will be.

But I do not think anyone is taking arc flash lightly, it is just that there are practical limitations as what can be done. All "good" engineers/Owner who know the risk would be taking all possible and affordable actions to prevent injuries. Code are really needed for not so good professionals/Owners who only wants to do a minimal job.

Unfortunately, the resources (money) are controlled by non-technical persons, accountants and lawyers in most cases. That is a discussion for another day.

In the end the onus of secruing one own safety is on the persons who do the work. If they do not take risk to their life seriously, it is so much others can do.

 

[Breakerboy]

I agree with much of what you have said, my only issue is when you place the onus of securing ones own safety on the worker. That worker is not necessarily up to speed on the recent information we now have available with the new calcs. I know that I could not have performed the new calcs myself and until we asked our managment to let our engineers perform those new calcs, including all of our specific equipment we have, I would not have known what we really had as a hazard.

Many people depend upon us to provide them this information. If the workers understood that work on energized equipment rated above 40 cal/cm2 is prohibited. And if they know that a fault could kill them and no PPE will protect them. Then they find out that we really might have that high of energy, and we just aren't going to go to the trouble to find out for them what the hazard really is, they might start saying NO. And if we believe that we might have energies that could be that high yet we fail to perform our responsible duties and do the real calcs, we now become negligent and may have to live our lives knowing "we could have saved a life that day, but we chose to look the other way".