Breakerboy
Electrical
- May 18, 2007
- 10
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!
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!