trying to figure out how much PPE I would need to operate 3000 Amp 480 Volt breakers.

ETS these are lever style, not push button

A really big stick.

Depends on fault interruption time and the fault current available.  It is not an easy calculation, we had a computer program do it but had to model the entire system.

Bottom line, there is no easy way to do it properly.

from http://ecmweb.com/content/calculating-arc-flash-energy-levels

While the National Electrical Code (NEC) requires only a generic label to warn of the possibility of arc flash danger on all equipment that is subject to arc flash hazards, NFPA's “Standard for Electrical Safety in the Workplace” (NFPA 70E-2004) goes a step further, requiring that, “A flash hazard analysis be done in order to protect personnel from the possibility of being injured by an arc flash.” This standard also requires that the analysis include a calculation of the flash protection boundary of each piece of equipment and determination of the required personal protective equipment (PPE) at the appropriate working distance for each piece of equipment.

Both NFPA 70E and IEEE 1584, “Guide for Performing Arc-Flash Hazard Calculations,” prescribe their own methods of calculation for determining the available arc flash energy at a particular piece of equipment. However, for both methods, typical working distances are given in Table 3 of IEEE 1584-2002.

I should add that arc flash is normally for work on exposed energized equipment.  Just operating the breaker does not necessarily mean (with a whole bunch of assumptions) that one needs to have arc flash clothing.

See http://www.csemag.com/single-article/your-questions-answered-electrical-systems-arc-flash-reduction-and-nec-24087-requirements/072ef19ddf963f0b4b548634a30b9c4d.html

NFPA 70E-2015, Section 130.2(A)(4) states that normal operation of electric equipment shall be permitted where all of the following conditions are satisfied:

   The equipment is properly installed.
   The equipment is properly maintained.
   The equipment doors are closed and secured.
   All equipment covers are in place and secured.
   There is no evidence of impeding failure.

I worked one summer for the Richardson Paint Company out of Richardson, Texas. They paint high line wire towers. Some really fucking big ones-500' supposedly are the largest.....Day three on the job and every morning we have a safety meeting before rigging up. One point of discussion is what the humidity etc...is that day and how far away from the lines you need to stay to avoid an arc.

So, the crews split up and the "pegger" has our first tower rigged and I'm up about 120' and painting away........KAFUCKINGBOOM......I look up and see a huge fireball and smoke cloud from where the other crew is working.....Immediately start hauling ass for the ground....

Guy was out on one of the arms.....got a little too close. Power arced and hit him. When I got to the tower he was stuck on the arm but very much alive...the hit had blown off his heel for some reason....they had one of the older guys up on the tower talking to the guy and finally he went out to him as he was in serious shock and drug/coaxed him back to the tower and got him down to the ground. Guy that got hit had been doing it for almost 20 years......

The money was good, guaranteed 15 hours of overtime per week....Going to college that money was nice.....


I quit right then and there. FUCK THAT.

NFPA 70E allows for hazard classification without calculating arc flash because most of the equipment installed is not labeled with that information.  Table 130.7(C)(15)(A)(a) lists when PPE is required and Table 130.7(C)(15)(A)(b) allows for general classification of common equipment.  If by operate you mean just throwing the switch on a closed panel you may still need PPE because of the hazard level of the equipment, you should have workplace safety program in place that can answer that for you. Look at this starting on page 32, best practice would be category 2 PPE.  It wouldn't hurt to read through the whole thing too.

Yes, throwing switches on closed equipment.  An old unit, nearly 20 yrs old.   My concern is that something fails in the breaker and two phase short and the fucking thing vaporises in my face.  

No way the 40 cal suit is gonna be enough.  Do they make telescoping sticks for this that might fit in a toolcase and that are adjustable for different lever dimensions?

Site guy gets back and says "20 cal based on the tx secondary . Dunno...

Well there's your answer, it's time to nut up, buttercup.

To operate that switchgear we would be required to wear a Cat 4 arc flash suit . Is there a way for that handle to be operated remotely with say , a rope with snap in the end rigged to a block above and or below ?

Left hand rule, look away.

All of it!

In a hurry, so no link, but Google chicken switch

I used to carry a length of 2x4 for such occasions

Did OP die?

R.I.P. JSmithXYY
Oct 2014 - Feb 2016

Is there a possibility of arc flash?

Yes?

Then it is hazardous.


You're welcome.

Arc Flash PPE, the difference between an open or closed casket.

Posted Via AR15.Com Mobile

I'm gonna guess that if you have to ask, you probably shouldn't be fucking with it.

If you do, make sure to set up a camera, just in case. I want to watch it on Youtube.

You have to model the entire system from the pole in.
Check out "EasyPower.com"

Engage an electrical engineering firm to model your plant or facility. They will furnish you placards to mount to each bus which denotes the PPE required for that equipment. We use a program called SKM to assist in modeling these fault currents and are licensed in FL, i believe

I hope OP doesn't die and his estate doesn't sue the people in this thread who gave him advice.

this

AND, Take a deep breath and hold it,,,...
That way your lungs aren't empty, you know how when you get scared and Take A Deep Breath?
Had a lot of classes, company had outside firm to come in and label every switch and what PPE was needed.
To cover their butts.
So many variables, no Second Chance.

This!

The place I work had no arc flash protocols when I started.  I almost got fired for not "flipping" a 5kA breaker.  Watching some other guy just walk up and flip it make my nutsack hurt.

This and this.

 

I hired a firm, no way could I manage a 100 year old million Sq ft industrial plant without help.


Roughly speaking, lower voltage higher amp equipment carries a higher arc incident energy but yes the entire system must be modeled for an accurate calc.


480 was the worst to work on because the phases are close together in switch gear and the amps are pretty high.


I had a 2400v mining cable blow itself apart in a test lab one day. Went phase to phase inside the love joy connector during motor startup inrush. It was a 1500 horse motor so it was a biggin for 2400v.


Electricity is perfect, which is cool...from a distance.


Anything over 50cal/cm2 and the bomb suit is just for easier cleanup.  The Kevlar will probably keep your body in a one bag condition.  3K amp at 480v has the potential for lots of incident arc energy, depending on the next upstream device.

Dumb motherfuckers gonna dumb.

They don't dumb anymore.  We had a firm come in.  Let's just say the engineers were excited when they saw our practices.  That coupled with the dusty  environment, it's a miracle no one got hurt.

Good. A pay check isn't worth dieing for.

There is a big ass stepdown Tx feeding it, size of a van, fed of the utility pole.  Could be 4k V or +11k or whatever it is.  Feeding a fucking factory, its their main input, so no way it is a fast tripping brkr.

It is a two source switch, PMs require failing either source and seeing to it that it transfers.

Was looking at a new arc sticker today, an 800 amp 480 switch feeding big delta Y transformers, was 4.6 cal/whatever energy incident @ 18," blast radius, or whatever they call it, of 42".  

I guess I am going to make a 2x4 piece and like cut a notch in it, maybe make a 3/4" plywood shield.  It takes all you got to close those sumbiches on the swing out levers, have to get your center real close.  

I am not having a scientific math based concern, it is more based on that video of that guy getting vaporized racking in the 4000 amp breaker.  Course, that was probably medium voltage.  

I am maybe going to buy a chicken switch or rent one for this job.  I think they are the future of safety, someday people will loom back on us throwing gear like this with a big WTF.

I will call that guy and find out exactly what that label says on there, no way a 20 cal suit makes one safe from that shit lol

When someone clearly over their head asks a question about their home wiring this is exactly what goes through my mind. I'm sure its happened and as a contractor if I give advice, I'm liable.



 

 
We used to work in 480v gear without any non-flammable clothing or skin protection. Looking back, and after edumacating myself, it was dumb...




...I don't have my 70E handy but HRC 4 would be my guess, not 2. Also, I am only familiar with the 2009 edition and thought that the most recent edition was making changes to the validity of the Hazard Risk Categories?




Also, googling '70E' provides images that I wasn't expecting ...

If the panel was open it would require category 4 ppe but to throw a switch on a properly rated and functioning enclosure does not technically require ppe under nfpa 70e.  Ppe is still recommended for higher risk equipment because shit happens when you party naked. Now off to google 70e.

http://e-hazard.com/arc-flash-resources/q&a/switching-circuit-breakers.php
http://www.emersonnetworkpower.com/documentation/en-US/Services/Market/Industrial/Documents/ERS%20Literature/White%20Papers/WP-02-004-Understanding-2015-Changes-NFPA70E.pdf

This is why most of my posts in these threads consist of "lol".

My friend has coined the term arftrician, calls these arftrician threads.

but you don't know what you're doing...

No shit.
The only time this shit REALLY bothered me was racking in breakers.

I know how to find my ass.

Just don't do this
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