Arc flash from broken primary

[quogueelectric]

I believe the bucket truck boom snapped the 34kv and it fell across the 13kv all sorts of badness going on here. The aluminum gutters on the house should get an oscar for this one http://www.youtube.com/watch?v=lEAtWiUGeiA&feature=related I hope the link posts

 

[mdshunk]

That one went around a month or so ago. It was a tree trimmer accident, if I remember right. Nobody was hurt, as I remember, but the house was toast.

 

[76nemo]

Where's the POCO tough guy willing to pull THAT meter???????

 

[76nemo]

I just talked to a supervisor over our grid early this week. The were transferring a temporary flat bed tranny over to a new tranny, 115K line. I asked him about PPE and working on their switchgear. He told me they are not required to wear full siuts. I asked him his personal opinion on that, he questioned what company I was from, like I was independent looking to raise a stink:roll:

Guess maybe I am the oldball

 

[jim dungar]

I just talked to a supervisor over our grid early this week. The were transferring a temporary flat bed tranny over to a new tranny, 115K line. I asked him about PPE and working on their switchgear. He told me they are not required to wear full siuts. I asked him his personal opinion on that, he questioned what company I was from, like I was independent looking to raise a stink:roll:

Guess maybe I am the oldball

OSHA has a different set of rules (other than NFPA 70E) for utility "line" workers. I believe that these utility rules will be incorporating arc flash protection in 2008.

 

[76nemo]

OSHA has a different set of rules (other than NFPA 70E) for utility "line" workers. I believe that these utility rules will be incorporating arc flash protection in 2008.

Do you have a different set of rules Jim? I know what I'd be wearing, 10, 20, 30+ years in, or not. I'm in suit, and I can only personally speak for myself

 

[jim dungar]

Do you have a different set of rules Jim? I know what I'd be wearing, 10, 20, 30+ years in, or not. I'm in suit, and I can only personally speak for myself

What suit would you be in when working on a 69kV line? Do you know what the typical arc flash incident energy is for a utility distribution system? While I have not performed these calculations, I am pretty sure that a NFPA70E hazard risk category 4 "moon" suit would be inappropiate.

 

[76nemo]

What suit would you be in when working on a 69kV line? Do you know what the typical arc flash incident energy is for a utility distribution system? While I have not performed these calculations, I am pretty sure that a NFPA70E hazard risk category 4 "moon" suit would be inappropiate.

Yes, better than wearing coverall's. I guess I would look like the Michelin man:roll: I see your point, point well taken, but I think most of these guys were in coveralls because it was so cold:-?

 

[zog]

OSHA has a different set of rules (other than NFPA 70E) for utility "line" workers. I believe that these utility rules will be incorporating arc flash protection in 2008.

Yes they do (NESC), there is alot of pressure for them to follow 70E, matter of fact the 2009 70E ROP's tried to squeze utilities in the next revision and they (Utilities) fought it hard, and still are. There is a good article in the Spring 2008 NETA World magazine on this battle written by a 70E commitee member.

 

[zog]

What suit would you be in when working on a 69kV line? Do you know what the typical arc flash incident energy is for a utility distribution system? While I have not performed these calculations, I am pretty sure that a NFPA70E hazard risk category 4 "moon" suit would be inappropiate.

Jim, if you have the software, play around with this senario, much less than you would think, low fault currents (Compared to some 480V systems) and fast clearing times.

 

[jim dungar]

Jim, if you have the software, play around with this senario, much less than you would think, low fault currents (Compared to some 480V systems) and fast clearing times.

Zog,

That is really what I meant when I said that HRC 4 clothing would be inappropiate. It would be excessive and probably not compatible with voltage ratings required. Also, the working distance, usually much more than the 18" @ 480V, also helps to "reduce" the AFIE at these higher voltages.

 

[don_resqcapt19]

The other thing that reduces the arc flash effect for linemen is the fact that in many cases they are not working in equipment...they are up in the air and the flash energy goes in all directions...not forced at the worker by the equipment enclosure.

 

[zog]

Zog,

That is really what I meant when I said that HRC 4 clothing would be inappropiate. It would be excessive and probably not compatible with voltage ratings required. Also, the working distance, usually much more than the 18" @ 480V, also helps to "reduce" the AFIE at these higher voltages.

Sorry Jim, misunderstood your post.