Arc Flash Protection

[davidr43229]

I don't visit any facilities. I work in one, and have done so for a long time

So did you facility do an ARC Flash Study, or are you preforming work based upon task?
Let me explain. Most work Level 2 and below can be done with "daily-wear", and safety glasses , voltage rated gloves and hearing protection.
You origionally asked me for proof of my facts and figures, which I whole heartly furnished to you , and even offered to send to you.
I submit that you are the one with the condescending attitude.
I wish you good luck in your retirement.
It's a change of work culture to protect lives.
I'm going to eat a girl scout cookie.....
Just my $.02

 

[realolman]

I did not ask you for proof of any facts and figures. I disputed your suggestion that we should view 70 E as "a positive effort by employers to clean up their act, and start to act responsible. "

Employers might comply, but they certainly did not initiate it.

Thanks for the explanation. That you don't know me at all, or what I do and have done, and yet feel you are entitled to "educate" me, is why I called you condescending.

 

[davidr43229]

I'd like to know where you get your information from

ah yeah you did...

 

[tomP]

davidr43229

So once you have opened the door and tested the load side of the main disconnect
for voltgage and it is deenergized can you remove PPE?

This would be with a plexiglass guard/cover protecting the main disconnect?

 

[WDeanN]

Tom,

That's a tough one that will depend on interpretation. If there is a guard over the line side of the main disconnect, then there should be no "exposed energized parts." But we both know that those things rarely stay in place as they should. Just as most panels doors are rarely tightened.

If possible, I would turn off the equipment at the source panel. If not, it may depend on the facility's interpretation. Here, we are not allowing, at this time, for ANY energized parts (480V or above) in the equipment, but will evaluate each circumstance as it comes up.

 

[WDeanN]

Realolman

I'm an electrician who went back to school to get my EE degree. Now I'm performing arc flash analysis and implementing some of the same policies that you're talking about. Just when I miss working with my tools, I realize how much more difficult it is now, due to some of the same policies that I have implemented.

There must be a balance between the safety policies and working. There is room for this in the 70E and the IEEE 1584 standard. Too many safety departments requard it as an all or nothing thing, however, and put little to no thought in what full implementation means. With a little thought, you can dress for the hazard, and still be fairly comfortable. A full analysis by someone who understands the standards and the engineering principles behind them, with engineering support to reduce the hazards will help with this.

 

[davidr43229]

TomP,

So once you have opened the door and tested the load side of the main disconnect
for voltgage and it is deenergized can you remove PPE

Is this a trick question?
If the line side of the disconnect is touch proof (IP20) AND if you have no yellow or orange colored wire, AND you have applied ground straps, then yes, verifying absense of electricity, you can remove all PPE.
Why? because the NFPA-70E is the EMployee Electrical Standard, or said a different way, if the Employee can not touch or come in contact with an Energized electrical condustor, the NFPA-70E goes way (yippie)
Just my $.02

 

[davidr43229]

WDeanN,
Now there's a perosn that knows what they are talking about.
Thank you.
If you have performed an Arc Flash study, you know exactly what to wear, because it's printed usually right on the label, just below the cal/cm*2 rating.
The origional clothing standard is a Dupont Clothing standard.
Additionally all testing and cals are open air "cals". No one has come up with the math to calculate the "In-a-Box", which amplifies the Arc Blast & Arc Flash more than the "Dc" (Dstance to a just curable burn), which we know the default is 4'.
Just my $.02

 

[tomP]

davidr43229,

No, it wasn't a trick question. Just trying to dispel some rumors using other people as references.

You do know what its like on the shop floor when something gets started around, don't you?

70+ electricians, all with different ideas and interpretations and most of them not correct.

I just can't wait 'till they get wind of having to use breast plates!!!
This is gonna be fun..

Seriously, we have some non-believers who think if there is any
voltage present (line side protected or not) they are required to use PPE.

 

[davidr43229]

TomP,

You do know what its like on the shop floor when something gets started around, don't you

Yes sir , I do !
The official line is: If you can not "Contact an energized electrical conductor", by means of cover,guards & shields.....
Short shory here, fella dropped a small screwdriver through some small heat slots in a cabinet, the screwdriver went phase to phase.....and went BOOM, So there are stories.....
Just my $.02

 

[WDeanN]

davidr:

Additionally all testing and cals are open air "cals". No one has come up with the math to calculate the "In-a-Box", which amplifies the Arc Blast & Arc Flash more than the "Dc" (Dstance to a just curable burn)

You should check out a couple of articles written by one of your competitors, Robert Wilkins with Shawmut. He and a couple others over there have incorporated physics models into the calculations to get a better correspondence (better Rsqruared) to the IEEE1584 data set. "Time-Domain Analysis of 3-Phase Arc Flash Hazard", not sure of original source. It hasn't gotten much response in the arc flash community.

Also Tammy Gammon has done some research and modeling in this area, and I think is now heading up the joint NFPA/IEEE arc flash project. Hopefully we will see some results from this.

 

[realolman]

ah yeah you did...

Ah... no I didn't...

I'll try for the third time:

I was disputing your suggestion that we think of NFPA 70 E as "a positive effort by employers to clean up their act, and start to act responsible. "

 

[realolman]

WDeanN

I am glad that someone seems to be able to at least acknowledge that it is an added burden in what is often an already difficult situation.

I think maybe that's all I'm looking for. I've done this stuff for 30 some years. I know darn well I have legitimate knowledge and experience. I have never experienced an arc fault in a cabinet in all that time. Am I lucky ... sure and I thank God for it. but for someone to say, as people have in this forum, that that is nothing but luck is absurd and insulting. Nobody does anything for that long on luck alone.

I think I should be consulted in what I should have to wear to do what I have done for 30+ years. Regardless of what any of you think, or whose power you can borrow to beat me into submission, none of you know more about me, my job, and how I do it than I do.

 

[kingpb]

The problem is that you cannot control equipment failure, and therefore you have been lucky, to some extent. Yes, you can certainly be commended for operating in a manor that safeguards yourself and others, unfortunately, accidents aren't on purpose, and equipment failure is random. So, in that regard luck, does play into the bigger picture.

 

[rick hart]

"What seems to be ignored is the number of times people do, and have done these things with no incident whatsoever. "


This would make a great epitaph!

What I knew 35 years ago when I started in the trade- both working at and visting sites- is way different from what I know today. I have some electricians that do not know more than what they learned as an apprentice and question the motives and validity of being told how to be safe. Those individuals place other electrical workers at risk. If it is only you that takes the risk and will not bring into play other electrical workers, your family or thier team of injury lawyers, carry on. The employers resposibilty is to train you of the risks associated with your job and to provide you with protection from those risks. However, their liability is often greater than thier ability to protect.

The number of times a risk is taken (or ignored) without consequence does not lessen that risk. This is what makes Russian Roulette so darned exciting.

 

[petersonra]

The number of times a risk is taken (or ignored) without consequence does not lessen that risk. This is what makes Russian Roulette so darned exciting.

You got that right. I don't have a problem with safe. I am in favor of safe.

What I have a problem with is the idiots that make up the rules almost never seem to actually have a good grasp of the actual hazards and what is a reasonable way to deal with them. I am not sure why, but it seems like safety departments are infested with people who do not have a clue beyond whatever article they read in the men's room last week in their favorite safety journal, that they than misapply.

I want to know why it is Ok for the completely untrained receptionist to plug in a computer with no special PPE, but if an electrician wants to check the voltage in the same outlet he has to wear PPE. The risk is the same, maybe even less for the electrician.

 

[davidr43229]

WDeanN,

You should check out a couple of articles written by one of your competitors, Robert Wilkins with Shawmut. He and a couple others over there have incorporated physics models into the calculations to get a better correspondence (better Rsqruared) to the IEEE1584 data set

http://www.ferrazshawmut.com/arcflash/getting_help/downloads/PCIC-2006-6.pdf
Just my $.02