Data Center Electrician wrote:
The DL breaker is an exception to the majority of breakers i see located behind a door. The open frame breakers may not have exposed live parts but they are behind arc shields and there are live parts. We are not worried about shock we are trying to avoid an arc blast. Opening a door creates a change in the gear and a movement that can in result cause other things to move. A door that was taken care of and opened smoothly on a DL breaker like this would most likely pose no threat. However, I have seen people smack a door to get it to pop open because it is sticky, this may pose a problem. My facility is spotless and i could eat off of the switchgear. My concern is that we develop acceptable habits. If it is acceptable to open a DL breaker door then will it be acceptable to open the door to a Siemens RL breaker? It will be hard to define this door or that door becuse of the differences in what is behind the door. Some of this is going to have to be based on knowlege and experience.
I assume you mean DS, never heard of a DL. I understand what you are saying and views like that are the reason I started this thread. However, the risk factor here is very low.
I had a friend burned in an arc flash last year just walking past an MCC when a starter picked up and failed causeing an arc flash that blew the door open, he was just walking by on his way back from lunch. So because that happened do we need to wear PPE to just walk past a MCC sitting on a production floor? How would that effect production at all large industrial facalities in the US? There has to be some level of acceptable risk.
Now the challange to the 70E commitee is to figure out how to assess that risk and write the standards in a usable way and still be enforceable. You can't put "knowledge and experience" in a standard because the people that think they have the most usually have the least.