It is currently Sun May 28, 2023 6:22 pm

What is the MAXIMUM distance where the typical arc flash label details are still readable?
 Less than 4 ft. (1.2 M) Between 4 and 8 ft. (1.2 - 2.4 M) Between 8 and 12 ft. (2.4 - 3.7 M) Greater than 12 ft. (3.7 M) It depends
You may select 1 option

View results
Author Message

 Post subject: Maximum distance where arc flash label is still readablePosted: Sun Oct 23, 2016 8:53 am
 Plasma Level

Joined: Mon Sep 17, 2007 5:00 pm
Posts: 1702
Location: Scottsdale, Arizona
This weekâs question is very subjective and is based on all kinds of variables such as lighting, eye sight etc. For an average person under normal conditions:

What is the MAXIMUM distance where the typical arc flash label details are still readable?

Less than 4 ft. (1.2 M)
Between 4 and 8 ft. (1.2 to 2.4 M)
Between 8 and 12 ft. (2.4 to 3.7 M)
Something greater than 12 ft. (3.7 M)
It depends

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Sun Oct 23, 2016 9:15 am
 Plasma Level

Joined: Tue Oct 26, 2010 9:08 am
Posts: 2173
Location: North Carolina
It really doesn't matter because they should be posted where they are accessible BEFORE you need to know that. The typical example is the OUTSIDE of an enclosure but another example would be at the base of the pole/mast below an overhead cutout/disconnect. Risk of an exposure to an arc flash event prior to this is almost none.

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Mon Oct 24, 2016 5:41 am
 Sparks Level

Joined: Tue Apr 17, 2012 8:19 am
Posts: 253
Location: Charlotte, NC
It depends on what the arc flash boundary is. You certainly would not want to be able to read that the AFB is 10 feet only once you are 3 feet away. It should be recognizable what the boundary is when you are standing at the boundary.

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Mon Oct 24, 2016 6:32 am

Joined: Mon Sep 26, 2011 2:17 pm
Posts: 21
Location: Metairie, LA - EIS
Before my cataract surgery last year, about 1 ft.
Now probably >4 ft.
Sorry, couldn't resist

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Mon Oct 24, 2016 9:44 am

Joined: Mon Oct 10, 2016 12:38 pm
Posts: 15
Hi Jim,

I agree with the "all kinds of variables" factor. Perhaps could one consideration be the average age of the workforce in a particular facility? If the average age is above 45 then one may consider a larger label with larger fonts. I have seen on a few occassions on an MCC where one larger label was installed in a conspicious location on the MCC in oppose to smaller labels on each cell. Myself being over 55 I would prefer a larger label with larger fonts that could be read further away

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Mon Oct 24, 2016 11:40 am
 Sparks Level

Joined: Fri Jul 08, 2016 10:01 am
Posts: 267
Location: Indiana
Lockout wrote:
Hi Jim,

I agree with the "all kinds of variables" factor. Perhaps could one consideration be the average age of the workforce in a particular facility? If the average age is above 45 then one may consider a larger label with larger fonts. I have seen on a few occassions on an MCC where one larger label was installed in a conspicious location on the MCC in oppose to smaller labels on each cell. Myself being over 55 I would prefer a larger label with larger fonts that could be read further away

Our standard label has the energy level in a much larger font than any other numbers or text on it for just that reason.

_________________
SKM jockey for hire

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Mon Oct 24, 2016 9:49 pm

Joined: Mon Jan 31, 2011 2:53 pm
Posts: 12
It depends of the label size, font and information on it. Usually the labels shows a lot of information not required by NFPA.

I think that if the worker prepare the task, allways could read it before energized parts are exposed.

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Tue Oct 25, 2016 5:11 am
 Sparks Level

Joined: Tue Nov 12, 2013 6:31 am
Posts: 238
Location: Port Huron, Michigan
Larry Stutts wrote:
It depends on what the arc flash boundary is. You certainly would not want to be able to read that the AFB is 10 feet only once you are 3 feet away. It should be recognizable what the boundary is when you are standing at the boundary.

It's not uncommon on switchgear in our facility for the number to be 80 feet plus. We would be required to post all of the labels on all the room doors in order to accomplish the goal of having the labels readable outside the boundary.

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Tue Oct 25, 2016 5:26 am
 Plasma Level

Joined: Mon Sep 17, 2007 5:00 pm
Posts: 1702
Location: Scottsdale, Arizona
Great comments everyone - thanks. I was originally asked by someone to post a question about what font size people use but thought asking about the distance and readability was really the issue. Yep, I'm falling into the aging category too as much as I try to resist it.

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Tue Oct 25, 2016 5:56 pm
 Plasma Level

Joined: Tue Oct 26, 2010 9:08 am
Posts: 2173
Location: North Carolina
https://deepblue.lib.umich.edu/bitstrea ... sequence=2
http://www.usscfoundation.org/USSCSignL ... sThumb.pdf

Aside from being very subjective, there are a lot of details that make something as "simple" as legibility anything but simple. When I last looked into this the one thing that was absolutely clear is that there is no agreement among standards.

Also although 70E and others all state that ANSI Z535 is the proper standard for safety signs, almost nobody actually follows it! But somewhat more troubling is that compliance with ANSI Z535 doesn't seem to enhance compliance with safety signs. See for instance:
http://pro.sagepub.com/content/49/19/1785.abstract

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Mon Oct 31, 2016 7:24 am
 Sparks Level

Joined: Thu Oct 18, 2007 7:10 pm
Posts: 262
Location: NW USA
Under 4' visibility is sufficient at the facilities I have worked at.

Larger labels would be a liabilty to find space to install in a fashion that didn't leave them prone to weather damage.

Putting them outside the Arc Flash Approach radius would also be confusing and require a road map of which labels are for which equipment.

Some of this comes down to familiarity, the workers will be looking for a label on the equipment, and then suit up in PPE prior to doing the work.

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Wed Nov 02, 2016 7:07 am
 Sparks Level

Joined: Tue Nov 12, 2013 6:31 am
Posts: 238
Location: Port Huron, Michigan
Arc flash boundary does not come into play until work is being done on the equipment. The label will be read right at the equipment, and the workers will take the proper precautions. This involves wearing the right PPE for the incident energy as well as securing the arc flash boundary (and other boundaries) so no one crosses over while work is being performed.

Top

 Post subject: Re: Maximum distance where arc flash label is still readablePosted: Wed Nov 02, 2016 4:17 pm
 Plasma Level

Joined: Tue Oct 26, 2010 9:08 am
Posts: 2173
Location: North Carolina
Voltrael wrote:
Arc flash boundary does not come into play until work is being done on the equipment. The label will be read right at the equipment, and the workers will take the proper precautions. This involves wearing the right PPE for the incident energy as well as securing the arc flash boundary (and other boundaries) so no one crosses over while work is being performed.

I'd agree pretty much universally in areas where 70E applies (industrial equipment) which is for the most part enclosed these days. The exception is open air equipment, particularly overhead distribution equipment, where approaching it is somewhat problematic in the first place.

That's not to say that there aren't things that can't be done. One particular case that I can think of was a large overhead pole line system with over 100 pieces of equipment attached to it ranging from small lighting transformers up to large substations for pumping stations. Going through the calculations found that except within the first quarter mile of the main substation, incident energy was well below 1.2 cal/cm2 at a distance of 8-10 feet away, what they used for hot sticks for moving jumpers, pulling cutouts, etc. So unless you were doing rubber glove work, "arc flash" was kind of automatic.

Top

 Display posts from previous: All posts1 day7 days2 weeks1 month3 months6 months1 year Sort by AuthorPost timeSubject AscendingDescending
 Page 1 of 1 [ 13 posts ]

 All times are UTC - 7 hours

 You can post new topics in this forumYou can reply to topics in this forumYou cannot edit your posts in this forumYou cannot delete your posts in this forumYou cannot post attachments in this forum

 Jump to:  Select a forum ------------------ Forum Library / Articles The Lounge    Question of the Week - What Do You Think?    Arcflashforum.com Feedback and Announcements    Off Topic Discussions    News in Electrical Safety Arc Flash and Electrical Safety    General Discussion    Electrical Safety Practices    Equipment to Reduce Arc Flash Dangers    Personal Protective Equipment (PPE) Arc Flash Studies    General Discussion    Arc Flash Labels    Software for Arc Flash Studies    System Modeling and Calculations    NEW! Electrode Configuration Library â 2018 IEEE 1584 Codes and Standards    CSA Z462 Workplace Electrical Safety    EAWR Electricity at Work Regulations, HSE - Europe    OSHA CFR Title 29    IEEE 1584 - Arc-Flash Hazard Calculations    NFPA 70 - National Electrical Code - NEC (R)    NESC - ANSI C2 - National Electrical Safety Code    NFPA 70E - Electrical Safety in the Workplace    2015 NFPA 70E Share It Here    Arc Flash Photos    Your Stories    What's Wrong Here? by Joe Tedesco
© 2022 Arcflash Forum / Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267 USA | 800-874-8883