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 Post subject: Tables 130.7(C)(15)(c) PPE Categories
PostPosted: Sun Oct 20, 2019 4:18 pm 

Joined: Sun Oct 20, 2019 12:04 pm
Posts: 2
I note that this table, correct me if I'm wrong, is only for use if the PPE Category is determined via the (a) or (b) table that precedes it and not for use where incident energy has been calculated. True?

And that in the event that incident energy analysis method is used, one uses table 130.5(G) to determine PPE AND that there are only two categories.

So if one uses SKM or one of the other programs to do a combination Short Circuit, Coordination and Arc Flash analysis, are the PPE categories 1 - 4 no longer relevant. And how does Table 130.5(C) giving the likelihood of arc flash occurence for varying tasks given varying equipment conditions?


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 Post subject: Re: Tables 130.7(C)(15)(c) PPE Categories
PostPosted: Mon Oct 21, 2019 4:58 am 
Sparks Level

Joined: Tue Jul 01, 2014 8:40 am
Posts: 101
Hello and greetings from North of the border. Yes you are correct that when performing an incident energy analysis, one would utilize table 130.5 (G) found on page 28. I am not sure what you mean by 2 categories here? The table is broken down into 2 sections- 1.2- 12 and greater than 12cal/cm2. The reasoning why this table was moved out of the annex and into the main body of the standard, and the same applies for CSA Z462 is that we want the worker to dress to the calculated incident energy level calculated. This is basically your "risk assessment"- hence the name "arc flash risk assessment". What you do not want to do is cross engineering in applying the task tables with your incident energy level. In the tables we are using assumed fault currents and overcurrent device clearing times. With the analysis one knows the fault current levels and clearing times. Again you are correct that the PPE categories- 1-4 are not relevant when doing an incident energy analysis


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 Post subject: Re: Tables 130.7(C)(15)(c) PPE Categories
PostPosted: Mon Oct 21, 2019 6:52 am 
Sparks Level

Joined: Thu Oct 18, 2007 7:10 pm
Posts: 261
Location: NW USA
Yes, when analyzing the arc flash exposure instead of using the tables, the results are portrayed as if there are only two categories, though it remains the responsibility of the worker to ensure all PPE exceeds the calculated exposure.

The code writers who never enter the field think this is a simplification. They also say that way you can distinguish whether the result is calculated or from tables (silly).

But giving up on the four categories (6 if you include 0 and unworkable) has been a source of much frustration at large plants I work at. They are well adopted to assigning PPE based on HRC, a handy way to categorize the caloric withstand, and it is foolhardy if these code writers think that personnel will have access to greater precision than what was thus presented. At one plant we now we print labels with A,B,C, etc representing what previously were the cut offs for 1, 2, 3, so the workers can easily identify the PPE needed, and yet we are not "liable" for misrepresenting the calculations as if they derived from tables (which seems difficult to imagine that as a liability).

It was working good in previous iterations of the standard, so of course they changed it.


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 Post subject: Re: Tables 130.7(C)(15)(c) PPE Categories
PostPosted: Mon Oct 21, 2019 9:04 am 
Arc Level

Joined: Mon Jan 18, 2010 11:35 am
Posts: 528
Location: Wisconsin
Gary B wrote:
It was working good in previous iterations of the standard, so of course they changed it.


But, they included the ability for 'site specific' PPE information to be shown on Arc Flash labels thereby allowing facilities to continue using previous PPE selection methodology.


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 Post subject: Re: Tables 130.7(C)(15)(c) PPE Categories
PostPosted: Wed Jan 22, 2020 10:01 am 

Joined: Fri Dec 30, 2016 3:13 pm
Posts: 6
Excuse me my english is not perfect.

It is also a doubt that I have. It is possible to use the EPP table “130.7 (C) (15) (c)”, when an incident energy method is used, for example that of IEEE 1584-2018.

However, article 90.4 (B), of the NFPA mentions the existence of permissive rules, denoted with the expressions are lost / not lost; and article 130.5 (F), indicates that the results of an incident energy analysis should not be used to specify the PPE according to the table “130.7 (C) (15) (c)” (being a permissive rule , must be understood as mandatory or flexible).

Thank you


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 Post subject: Re: Tables 130.7(C)(15)(c) PPE Categories
PostPosted: Fri Feb 21, 2020 12:40 pm 

Joined: Wed Feb 19, 2020 8:55 am
Posts: 1
Nerf,
The complex phrasing is sometimes difficult to follow, even without the additional complexity of working in a second language. I understand your confusion!

The text at the beginning of Article 130.5(F) includes this statement:
Quote:
The results of an incident energy analysis to specify an arc flash PPE category in Table 130.7(C)(15)(c) shall not be permitted.

This is a mandatory statement, not a flexible statement. It is not permitted.

Table 130.7(C)(15)(c) is only for use with the "Arc Flash PPE Categories method," as described in Article 130.7(C)(15). That is:
  1. Refer to Table 130.7(C)(15)(a) for AC systems, or Table 130.7(C)(15)(b) for DC systems, to see which PPE category applies to the task/equipment. If the task/equipment is not listed, this approach is not permitted.
  2. If a PPE category is found, refer to Table 130.7(C)(15)(c) to see which PPE elements are needed for that PPE category.

Some facilities have continued to use the categories as a shorthand method to communicate to workers about what PPE is needed. The standard prohibits employers from using the categories to decide what PPE is needed (when an incident energy analysis is performed). The distinction is problematic, even for native English speakers.


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