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 Post subject: Arc Flash Labels-PPE Category
PostPosted: Fri Nov 18, 2016 7:22 am 

Joined: Fri Jun 10, 2016 7:17 am
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In the NFPA 70E-2015 Handbook, page 122, 130.5(D) states incident energy or PPE category shall be on the equipment arc flash label, but not both. Yet when reviewing Annex H in the NFPA 70E-2015 handbook, on page 279 it states "Arcflash PPE categories may be applicable when using incident energy method to perform an arc flash risk assessment. When performing an incident energy analysis, the arc flash labels created may include an arc flash category". Am I missing something or is this a mis-print??


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 Post subject: Re: Arc Flash Labels-PPE Category
PostPosted: Fri Nov 18, 2016 8:01 am 
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No, some companies will have a Site Specific PPE Level which can be put on a label instead of the incident energy value. Annex H gives an example of that in Table H.2.

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 Post subject: Re: Arc Flash Labels-PPE Category
PostPosted: Mon Nov 28, 2016 9:50 am 

Joined: Mon Feb 22, 2010 10:24 am
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The intent of this requirement not to post both PPE categories and incident energy on labels is to avoid mixing the incident energy method with the tabular methods and to insure that a risk assessment is completed beyond the calculations. It is allowed for a facility owner to determine its own unique PPE levels and that may be posted on the label as well as the incident energy. It is not the same as the PPE categories listed in the tables 130.7(C)(15) and 130.7(C)(16). There is a difference between PPE categories defined in 70E and site specific PPE levels determined following a risk assessment and clothing policy.


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 Post subject: Re: Arc Flash Labels-PPE Category
PostPosted: Mon Nov 28, 2016 10:41 am 
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The crux of the issue is that when it comes to arc flash, 70E and NESC provide two methods for determining arc flash protection. The first method is to do all the work yourself with an engineered solution. The second method is to use the pre-engineered tables in the standard.

The inherent problem with the tables with either standard is that there ar assumptions built into them that may not apply to your specific conditions. Second by nature they produce extremely high ("conservative") recommendations. An engineered approach is customized to the site and overcomes all of these problems. But the consequence of the engineered solution is that the end user is responsible for every aspect from deciding what tasks are safe vs. those that require PPE to determining what the hazard is and based on the hazard what PPE is required. When Annex H didn't exist determining correct PPE was pretty much something provided by a PPE vendor/manufacturer, and most of them ducked the question for liability reasons, leaving the end user without a complete solution. Many end users thus incorrectly mixed and matched the engineered and table approaches. To avoid this conflict, 70E mandated the label requirement and has wording stating that this is not acceptable.

For various reasons the tables in 70E has some goofy issues in them. For instance on the same piece of equipment depending on the task even though working distance for instance did not change, PPE for 1.2, 8, or 40 cal/cm2 would be required for the exact same piece of equipment. This changed with the 2015 edition so that now whether or not PPE is required depending on the task, and the PPE level (basically incident energy), and finally the PPE required are three separate tables.

There is today with the 2015 edition no reason that end users can't simply adopt one or more tables from 70E while substituting another (engineered) approach for everything else. The end result is an engineered solution. Note that in doing so the end user is obviously responsible for validating the correctness of this approach, as opposed to using the tables as-is in 70E which is simply following a standard with no responsibility attached for the correctness of the underlying system.


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