Arc Flash

[sandsnow]

I went to a seminar on arc flash last week. we were told that examination of energized equipment could possibly require protection. As an inspector I have done this many times. The electrician removes the covers while energized. I searched Cal/Osha (since I'm in CA) and could only find that workers shall have protection while "working" on energized, but no description of what "work" is. I'll have to check, but I do not believe we have adopted NFPA 70E where there may be more requirements.
1. Does anyone have a Cal/Osha definition of work?

2. Do any inspectors require eqipment to be de-energized for inspection?

3. If, so is there any reference to any osha safety orders or anything in NFPA 70E?

Thanks

 

[rbalex]

Re: Arc Flash

"Working On" and "Working Near" are both defined in 70E.

70E also defines various "Approach Boundaries" that establish specific degrees of permitted approach to energized equipment and PPE that may be required.

FedOSHA currently may enforce 70E under the General Use clause of 29CFR1910.4

California is one of four "State Programs" that works under an "Operational Status Agreement" with FedOSHA and has never received FedOSHA "final approval."

[ July 26, 2004, 11:28 AM: Message edited by: rbalex ]

 

[tom baker]

Re: Arc Flash

70E should be included with the NEC. We will only see more and more requirements for electrical safety. Trade groups are pusing the issue. The issue being taught now is to deenergize first. Only work hot if you have to.

 

[ron]

Re: Arc Flash

I'm not familiar with the Cal/Osha, but federal osha has text such as "Employees working in areas where there are potential electrical hazards ..." 1910.335(a)(1)(i)

I do a lot of electrical survey work as part of my work, and that is considered "work" in areas where there are potential electrical hazards in my book.

Infrared technicians also work near equipment and arc flash and shock protection boundaries apply to them.

 

[rbalex]

Re: Arc Flash

Took a while to find this (searches are limited to lunchtime at the moment):

California Title 8, Division 1, Sections 142.3(b)(2)

Essentially is says CalOSHA shall enforce anything FedOSHA does. FedOSHA is not required to enforce 70E - but it generally does.

I concur with Tom's comments. It was not documented in the ROP stage of the 70E-2004 because there was only a simple majority in support; but there was a potential Technical Committee proposal to prohibit working on live equipment where the incident energy was 100 cal/cm2 or greater - no matter what PPE was available.

 

[ron]

Re: Arc Flash

rbalex,
Since the highest PPE recognized by 70E is '4', which is rated upto 40 cal/cm2, how would someone potentially work on equipment with higher than 40. Was the potential Technical Committee proposal at a particular working distance?

The way I have been recommending clients to handle a high incident energy situation, if they insist on working energized, is that I will calculate the working distance that brings the incident energy down to below 40 cal/cm2. If they can do what they want from that distance, then more power to them. Generally they want to IR scan, so for example at 67 inches (assuming that is the calculated working distance) from the energized bus, they put on their category 4 suit and other appurtenances and they setup their camera with a 2x or 3x lens and a very good spot ratio camera and go bananas.

 

[rbalex]

Re: Arc Flash

Ron,

If you have it availble to you, the 70E-2004 "Preprint had a Table 220.6(B)(9)(C) which had a Risk Category of 5 and PPE of 100.

70E was totally rewritten - it was originally to be published in 2003. I left the TC mid-cycle and wasn't party to the final changes.

While there is no PPE currently rated 100, there are many products capable of it and there was a strong push to recognize them.

Bob

[ July 27, 2004, 12:10 AM: Message edited by: rbalex ]

 

[ron]

Re: Arc Flash

At this point the NFPA 70E-2004 only has "Table 130.7(C)(11) Protective Clothing Characteristics" which only reflects PPE category as high as 4, less than 40 cal/cm2.

Maybe 70E-2007 will have a PPE Cat 5 suit.

[ July 27, 2004, 07:11 AM: Message edited by: ron ]

 

[rbalex]

Re: Arc Flash

Ron,

I'm aware of the current content; I was simply stating what was batted around the last time I was there and the state 70E was in at the ROP stage.

I haven't attended any recent 70E meetings so I can no longer speak with any certainty. I reviewed the current TC makeup and it hasn't changed too much so I imagine the current Table will be maintained for a while.

This was an issue with very strong feelings on both sides and the split was nearly 50-50 as I recall. There was no question in my mind that both sides were genuinely concerned about worker safety. Both sides definitely favored "de-energize if practically possible." A clear rubric for reasonably determining what was "practical" with respect to the risk of not doing the work "live" was the debated issue.

Bob

 

[sandsnow]

Re: Arc Flash

Thanks everyone.especially for the links,Bob

After seeeing videos of arc falsh testing and what happened to the test dummies, it makes you think twice about putting your face near something enrgized or standing behind someone taking covers off.

I was told at our seminar that back in Michigan and Indianna that fines had been levied for non-compliance wit arc flash and PPE rules.