Arc flash label "warning" vs. "dangerous" labels

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lielec11

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Do you know if it is stipulated anywhere in NFPA 70E the requirement of "DANGER" on equipment with incident energies over a certain limit? Since the 2018 version, the incident energy calculation method only includes 3 levels, below 1.2cal, between 1.2 and 12 cal, and over 12 cal.

In SKM, the table echos the same. Is that to say that there is no "DANGER" anymore?
 
There's nothing in NFPA 70E (unless changed in the latest version) that says anything about this. It is certainly not required by NFPA 70E. There is an ANSI standard on safety labels that covers, in general terms, when to use "WARNING" and when to use "DANGER". It's up to you to decide which is applicable. We used WARNING on all labels regardless of the incident energy level. The notion that at some energy level it should change from WARNING to DANGER is someone's bright idea and not required by any code or standard. Many people put DANGER (and red header) when incident energy exceeded 40 cal/cm2. This is pretty common, but not a standard by any means.
 
David Castor said:
There's nothing in NFPA 70E (unless changed in the latest version) that says anything about this. It is certainly not required by NFPA 70E. There is an ANSI standard on safety labels that covers, in general terms, when to use "WARNING" and when to use "DANGER". It's up to you to decide which is applicable. We used WARNING on all labels regardless of the incident energy level. The notion that at some energy level it should change from WARNING to DANGER is someone's bright idea and not required by any code or standard. Many people put DANGER (and red header) when incident energy exceeded 40 cal/cm2. This is pretty common, but not a standard by any means.
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We have always printed our labels over 40cal/cm2 as red "DANGER", but I honestly never knew why, especially after the table changed. I feel like it scares the property owners from working on certain equipment more than it should (I'm not saying that no danger exists!). However, when I print the arc flash tables in SKM, it still says "DO NOT WORK ON LIVE!" under the PPE header. Curious why they still might do that?
 
Hey :) The RED DANGER labels were a result of an Informational Note (IN) in the 2012 edition of 70E that stated "Greater emphasis may be necessary with respect to de-energizing ..." when the IE is over 40 cals. The software folks all jumped on that and triggered RED DANGER labels for everything over 40 cals. The next edition of 70E excluded that IN. RED DANGER is not in accordance with ANSI Z535, the labelling standard, and all arc flash labels should be ORANGE WARNING.
 
The red labels were being used prior to 2012. It's just someone's bright idea. Whether or not using DANGER and red header is not in accordance in ANSI Z235 is really a matter of interpretation. We have always used WARNING for everything, but I suspect we are in the minority to be honest.

I think the intent of the DANGER header is absolutely to scare people. But it isn't consistent with the intent of NFPA 70E, IMO. There has long been a common belief that NFPA 70E prohibits energized work for incident energies over 40 cal/cm2. But it has never really said that - at least explicitly.
You can change the label template in SKM to whatever you want. NFPA 70E really says very little about the specifics of labeling, beyond the minimum requirements.
 
JoeStillman said:
I was taught that there is no PPE rated over 40 cal, hence the red labels. Maybe there's new equipment available?
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That's a good point as no suit is rated greater than 40 cal/cm2. But I also agree with others stating that 70E doesn't really take a stance on this at all. This entire field is more art than science sometimes I guess...
 
I thought +65 cal suits have been available for years.

Most people think the software companies are also NFPA70E experts, but my experience is they aren't.

From what I see posted on forums, most people, including trainers, have not been updating their NFPA70E training every couple of years. I often see things that were 'refuted' more than 10 years ago, like the 40 cal PPE being equated to body bags. I also hear a lot of company specific policies being confused with industry standard policies, like no work ever above 40 cal.
 
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That's a good point as no suit is rated greater than 40 cal/cm2.
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There are 100 cal/cm2 suits available - not a new thing. NFPA 70E Categories Method PPE descriptions don't go above Category 4 with a max of 40 cal/cm2. There used to be a Category 5 that went up to 100 cal/cm2 in NFPA 70E, IIRC, but it was removed a long time ago.

The PPE descriptions for the calculated method don't state an upper limit - unless that's changed. But many people have concerns about so-called "arc-blast" pressure waves that PPE is not rated for. But again, there is nothing in NFPA 70E that quantifies arc-blast.

As I used to explain to my training classes - it's not an exact science.
 
David Castor said:
There are 100 cal/cm2 suits available - not a new thing. NFPA 70E Categories Method PPE descriptions don't go above Category 4 with a max of 40 cal/cm2. There used to be a Category 5 that went up to 100 cal/cm2 in NFPA 70E, IIRC, but it was removed a long time ago.

The PPE descriptions for the calculated method don't state an upper limit - unless that's changed. But many people have concerns about so-called "arc-blast" pressure waves that PPE is not rated for. But again, there is nothing in NFPA 70E that quantifies arc-blast.

As I used to explain to my training classes - it's not an exact science.
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The typical reason for >40cal/cm2 values is long protective device clearing times not extremely high current/blast values.
 
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