Arc flash PPE while not working

[tcrews17]

Hi all,

I've been lurking on here for years and have found many good answers... but I've been unable to find one.

Most of the time when I think of arc flash and arc flash studies, I think of working on energized equipment. A certain energy level requires a certain PPE level while working.

What about when no one is working, and the equipment is operating under normal conditions. If someone is just walking by and crosses the arc flash boundary, are they required to wear arc flash PPE?

thanks,
tc

 

[sameguy]

Need exposure to live components for arch flash; so should be none unless your out in a yard. You would have your ppe on because you are following the rules to enter the yard after you unlocked the gate to get in the yard.

 

[zog]

Need exposure to live components for arch flash; .

Not true, 99% of the equipment enclosures out there is not designed to contain an arc flash.

 

[zog]

Hi all,

I've been lurking on here for years and have found many good answers... but I've been unable to find one.

Most of the time when I think of arc flash and arc flash studies, I think of working on energized equipment. A certain energy level requires a certain PPE level while working.

What about when no one is working, and the equipment is operating under normal conditions. If someone is just walking by and crosses the arc flash boundary, are they required to wear arc flash PPE?

thanks,
tc

Only when you are interacting with the equipment. That being said, I have a customer that had an employee severely injured from an arc flash from a MCC that he was just walking by, wrong place, wrong time.

 

[tcrews17]

That's what I was thinking as well. Guess the wrong place, wrong time scenario is where I was getting hung up and couldn't find a clear answer in 70E or elsewhere. Thanks for the feedback

 

[sameguy]

Not true, 99% of the equipment enclosures out there is not designed to contain an arc flash.

Zog , I was replying to just walking by, not working on equipment and the need to wear ppe as per the op stated question as I understood it.

 

[gray.one]

Arc flash PPE while not working

It’s true that 70E only requires the PPE when the equipment isn’t in a normal operating state, buttoned up and all. Some companies go further, recognizing that most gear isn’t arc resistant.

I met a guy that had a switch blow up on him while he was closing it. He alway suits up for operation.

A lot of companies buy remote operators for the same reason.


Sent from my iPhone using Tapatalk

 

[GoldDigger]

It’s true that 70E only requires the PPE when the equipment isn’t in a normal operating state, buttoned up and all. Some companies go further, recognizing that most gear isn’t arc resistant.

I met a guy that had a switch blow up on him while he was closing it. He alway suits up for operation.

A lot of companies buy remote operators for the same reason.


Sent from my iPhone using Tapatalk

Arc flash calculations are intended to apply to anyone interacting with the equipment, whether they are "working on it" or not. To me that includes operating a switch or breaker if there is any potential of causing an arc flash. This sort of possibility is widely discussed.
120V snap switch on light circuit: probably not.
MV service switch, probably!

 

[Jraef]

The key concept is "interacting" with the equipment. That includes operating circuit breakers through the door. But the NFPA and OSHA is concerned with workers WORKING on the gear for the most part.

It's true that people CAN be hurt in an event, even with the doors closed, just by being there, but the risk is considered too low to be made mandatory. Hence the concept of "Arc Resistant" equipment, designed to contain the force of an arc blast or deal with it in a safe manner. Some people want AR gear because the gear is located in areas where people are frequently nearby. The classic is along a factory wall that is used as a passageway.

This video shows what can happen even with doors closed on a low voltage MCC that is not Arc Resistant. Most of it shows the operator sniffing, looking etc. trying to figure out where the smell is coming from, he even rolls up the door to check if it's coming from outside. The flash happens at about 1:49 if you don't want to wait.

 

[Jraef]

This one gets right into it. Notice that although some doors are open, the test dummy is in front of the CLOSED doors and the arc flash happens in the gear lineup, but even though there are open doors elsewhere, the blast pressure is so great that it blows the doors off in the CLOSED part.

 

[Jraef]

Here's a test video of MV Arc Resistant switchgear showing how it redirects the blast pressure.

 

[Brad45]

Company PPE Policy and "Non-Interaction"

Company PPE Policy and "Non-Interaction"

I do AFRA on a lot of low kVA pump jack sites where pumpers and other personnel very regularly walk by disconnect and panels that are energized but are not working on them. In pretty much all these cases the company minimum PPE level is required but nothing additional. If anyone was planning on opening a panel to check/ change a fuse, etc., they would be required to gear up and get their 0 gloves and face shield.

No doubt it certainly depends on the nature of the facility and the level of available fault current. Had a guy tell me one time that their janitorial staff was required to suit up to sweep the floor at some areas within their facility. Seems like overkill but with a random fault it might be a life saver.