Arc Flash/Resistant
Arc Flash/Resistant
(OP)
Hello all,
For some reason the search function is not working right now...so before I forget I will post my question anyways.
What is the difference between Arc Resistant, and Arc Flash?
It was my understanding that Arc resistant was a type of switchgear that under a faulted condition the gas pressure would be routed away from any personnel through the roof etc. It was also my understanding that Arc flash was a study that determined how far (or what type of protective clothing) a person had to be from an enclosure to be safe.
I was recently told by a manufacturer rep that eventhough you buy arc resistant gear, you still have to wear the arc flash protective gear? That the two have nothing to do with each other?
Can someone please explain?
Best Regards,
TULUM
For some reason the search function is not working right now...so before I forget I will post my question anyways.
What is the difference between Arc Resistant, and Arc Flash?
It was my understanding that Arc resistant was a type of switchgear that under a faulted condition the gas pressure would be routed away from any personnel through the roof etc. It was also my understanding that Arc flash was a study that determined how far (or what type of protective clothing) a person had to be from an enclosure to be safe.
I was recently told by a manufacturer rep that eventhough you buy arc resistant gear, you still have to wear the arc flash protective gear? That the two have nothing to do with each other?
Can someone please explain?
Best Regards,
TULUM






RE: Arc Flash/Resistant
RE: Arc Flash/Resistant
The manufacturer rep said that even with the doors closed the protective gear would need to be worn when within a certain area due to current standards?
I know it sounds strange, but anyways just want to clarify.
regards,
TULUM
RE: Arc Flash/Resistant
I don't believe that 70E addresses "arc resistant" gear, any 70E experts care to comment?
RE: Arc Flash/Resistant
However, I think it would be reasonable for a company to develop safety rules related to work around arc-resistant gear that took its protective function into account.
Also, there are different levels of arc-resistant gear - some is designed such that only the front of the gear is rated to withstand arcing faults. I think the Canadian spec has three different categories. I'm not sure about the new ANSI spec for arc-resistant switchgear.
RE: Arc Flash/Resistant
RE: Arc Flash/Resistant
The notion that having a closed door on an MCC bucket reduces arc-flash risk automatically to Hazard/Risk Category 0 is controversial at best. (Category 0 does NOT mean zero risk by the way).
NFPA-70E does not say this. There is a table in NFPA-70E that may be used "in lieu of" an arc-flash hazard evaluation that does give a Category 0 to certain tasks on MCCs when the bucket doors are closed - but within certain short circuit and clearing time restrictions.
Except for arc-resistant switchgear, no electrical equipment is tested for its ability to withstand arcing faults. It's easy to conduct arcing tests in MCCs that will blow the bucket doors completely off.
Closed doors are a good thing, but do not guarantee protection.
RE: Arc Flash/Resistant
RE: Arc Flash/Resistant
Category 0 requires non-melting clothing (generally cotton), but the clothing is not required to carry a specific arc energy rating.
RE: Arc Flash/Resistant