AF Data Collection PPE

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aLWAYS_lEARNING-112532

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Can you safely collect data for an arc flash study with no PPE? For example, electricians wearing PPE remover covers and you then come in the room and write down breaker model / conductor sizes staying back at least 18" from the gear. This would be mainly for 480V and 208V switchboards and panel boards
 
Not sure where you are getting the 18" distance, but if you stay outside the Restricted Approach Boundary, it's probably possible in theory per NFPA 70E. This is covered in Table 130.5(C). (2021 version of 70E). This is how the infrared thermography folks avoid wearing PPE. It probably meets NFPA 70E, but I think it's really sketchy and if it were up to me, I'd require the data collector to wear the same PPE as everyone else.

It's also worth developing approaches to data collection that reduce the need to remove covers or expose live parts.
 
It would seem that the chance of an arc fault is much lower visually observing equipment from a distance than actively removing covers. To my 'non-expert' eye (I am not trained in evaluating arc fault hazard), it seems totally reasonable that there be different requirements for the person removing and re-installing the panels vs the person taking notes from a distance.
 
winnie said:
It would seem that the chance of an arc fault is much lower visually observing equipment from a distance than actively removing covers. To my 'non-expert' eye (I am not trained in evaluating arc fault hazard), it seems totally reasonable that there be different requirements for the person removing and re-installing the panels vs the person taking notes from a distance.
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I would still need to be rather close, at least 1ft away, to be able to read the breaker labels and wire sizes. Even if Im a foot away looking in the gear, an arc flash COULD occur
 
Agreed, an arc flash could occur.

My question: what is the initiating event that triggers the arc flash? Could the probability of that initiating event be reduced enough to reduce or eliminate the need for PPE?

-Jonathan
 
winnie said:
Agreed, an arc flash could occur.

My question: what is the initiating event that triggers the arc flash? Could the probability of that initiating event be reduced enough to reduce or eliminate the need for PPE?

-Jonathan
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The electrical system is of unknown condition, and no current arc-flash assessment or labeling exists for this very old installation. A fault could occur downstream in another building, producing fault currents that exceed the AIC of the breaker under review. If the breaker is subjected to fault levels beyond its rating, it may catastrophically fail, blowing pieces in my face
 
aLWAYS_lEARNING-112532 said:
If the breaker is subjected to fault levels beyond its rating, it may catastrophically fail, blowing pieces in my face
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I replaced about 20 sections of MMC that had been in service for over 30 years because when they did an arc flash study, they found the breakers in the MMC had AICs much lower than the available fault current.
 
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aLWAYS_lEARNING-112532 said:
The electrical system is of unknown condition, and no current arc-flash assessment or labeling exists for this very old installation. A fault could occur downstream in another building, producing fault currents that exceed the AIC of the breaker under review. If the breaker is subjected to fault levels beyond its rating, it may catastrophically fail, blowing pieces in my face
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So the risk of something wrong is high enough to concern you, you are willing to deal with the hassle of PPE, but the people who might lose a bit of bonus don't want to pay for the PPE.

I don't suppose they are willing to even think about the cost of a shutdown, and haven't bothered to consider the cost of an unplanned shutdown should the switchgear become an investigation scene.
 
This is why I tend to buy the newest phone for the better camera lol. I try to use the zoom to capture details. It doesn't always work. But on relatively new breakers or wires, it can.
 
A few years back one of our service electricians was out on his own assisting a EE opening up panels for one of those arc flash studies. He always had a hard time finding the EE and a few times the EE got impatient opened up the panel without him nobody cared.
Later when the electrician opened one up one of old panels a bunch of the breakers started falling out and one broke apart. It was a 208 panel with old plug on type breakers that had cracked and broken with age or had suffered an impact somehow, fortunately nobody was not injured, there was some sparking and smoke, after that the EE always waited until our guy was there.
 
How does everyone collect the data? Do you disconnect the power or wear PPE? Collecting data can be dangerous.
 
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