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 Post subject: PPE Flow-chart
PostPosted: Tue Jun 29, 2010 6:22 am 
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I am new to the forum but am finding some very interesting reading and discussions. My HVAC techs have detailed some tasks that cover 90% of electrical activities and are asking for a flow chart or quick reference guide to cover these. Instead of re-inventing something I thought I would ask if anyone has anything in place like this. The list is below:

replace breaker in electric panel
replace fuse in disconnect
voltage testing in disconnect
voltage testing in equipment electric panel
amperage testing in breaker panel
amperage testing in disconnect
amperage testing in equipment electric panel

voltage rage from 24 to 480 volts
I know depending on voltage and distance is going to impact much, but any information from your experiences is appreciated.


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PostPosted: Tue Jun 29, 2010 6:40 am 
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I would try to get a copy of Table 130.7(C)(9) from NFAP 70E. It shows what category of PPE is needed for most of your work list. Generally speaking, your techs will be in Cat 2* or less, depending on the tasks. However, be aware of the limitations of available short circuit current and fault clearing times associated with the table values.


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PostPosted: Tue Jun 29, 2010 8:40 am 
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docweaver wrote:
I am new to the forum but am finding some very interesting reading and discussions. My HVAC techs have detailed some tasks that cover 90% of electrical activities and are asking for a flow chart or quick reference guide to cover these. Instead of re-inventing something I thought I would ask if anyone has anything in place like this. The list is below:

replace breaker in electric panel
replace fuse in disconnect
voltage testing in disconnect
voltage testing in equipment electric panel
amperage testing in breaker panel
amperage testing in disconnect
amperage testing in equipment electric panel

voltage rage from 24 to 480 volts
I know depending on voltage and distance is going to impact much, but any information from your experiences is appreciated.


Is this along the lines of what your looking for?


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PostPosted: Tue Oct 04, 2011 7:54 pm 
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Nice wall chart Allison, thanks!


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PostPosted: Wed Oct 05, 2011 5:22 am 
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Volta wrote:
Nice wall chart Allison, thanks!


Yeah but there is no longer a 2*


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PostPosted: Sun Oct 09, 2011 3:29 pm 
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I am not familiar with 2*. It is shown on this chart as 8 cal/cm┬▓. What do you think, for use as a quick reference, should those tasks generally be considered as an HRC 2 or 3?


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PostPosted: Tue Dec 27, 2011 4:20 am 
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Great chart. Love the colors

Now, regarding the question of there no longer being a 2* HRC. How is everyone handling this? We carry the balaclava for that situation.

Another question is in regards to those levels. We have recently been issued full FR uniforms. Shirts are 11 cal/cm2, pants 12 cal/cm2 and sweatshirts with hood 33 cal/cm2. Can that hood be used in the stead of the balaclava?


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PostPosted: Tue Dec 27, 2011 8:45 am 
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A full hood appropriately rated eliminates the need for a balaclava with face shield. The 33 cal sweat shirt will only bring up your PPE to that rating if you add higher PPE to the legs than the 12 cal pants. All parts of the body must be covered at the required level of PPE. Your PPE should be arc-rated and not simply fire retardent.


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PostPosted: Wed Dec 28, 2011 3:17 am 
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George wrote:
A full hood appropriately rated eliminates the need for a balaclava with face shield. The 33 cal sweat shirt will only bring up your PPE to that rating if you add higher PPE to the legs than the 12 cal pants. All parts of the body must be covered at the required level of PPE. Your PPE should be arc-rated and not simply fire retardent.


Please explain the difference between arc-rated and fire retardant. All of our gear now has the ATPV rating, as well as the HRC.

Even though there is technically no longer a 2*, where is the line transitioning between the steps? My documenation only indicates a minimum arc rating of 8 cal/cm2 for both, but the need for a balaclava for the 2*. In this case, as long as the required ATPV is 12 or below we should be good with the hood up, correct?


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PostPosted: Wed Dec 28, 2011 8:42 am 
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Nice Flow Chart, but I think one thing is missing, but maybe that is my opinion...
Wouldn't a back-up/safety watch person be a good idea for the higher risk jobs? Not making it an option by the worker's judgement call, but rather a part of the table along with your PPE.. In my opinion, the safety person would have to be a qualified electrician with the proper ppe and rescue equipment (radio, rescue stick, etc)..
Just a thought...


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PostPosted: Wed Dec 28, 2011 3:32 pm 
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MIControl wrote:
Please explain the difference between arc-rated and fire retardant. All of our gear now has the ATPV rating, as well as the HRC.

Even though there is technically no longer a 2*, where is the line transitioning between the steps? My documenation only indicates a minimum arc rating of 8 cal/cm2 for both, but the need for a balaclava for the 2*. In this case, as long as the required ATPV is 12 or below we should be good with the hood up, correct?


The difference between arc rated and fire retardant (or flame resistant): not all FR gear is arc rated, but all arc-rated gear is FR! "FR" gear that isn't arc-rated will not be labeled with an ATPV value.

2 and 2* were both 8 cal, with the difference being face/head protection. 2* is gone, and at HRC 2, the balaclava is required (along w/ hearing protection and a face shield). You can use a double-layer arc flash suit hood (we like to call 'em the bee keeper suits) instead of the balaclava if you wish.


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PostPosted: Thu Dec 29, 2011 6:43 am 
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MIControl wrote:
Even though there is technically no longer a 2*, where is the line transitioning between the steps?


The transition point I think you are looking for came from Table 130.7(C)(9) of the 2009 edition of 70E. Whenever it was felt that a task warranted an increased level of protection to the head and neck the * was added to category 2 making it 2*.


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PostPosted: Wed May 09, 2012 1:11 pm 
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From the flow chart:
Specific Notes: (as referenced within the tables)
2. Max. of 25 kA short circuit current available; max. of 0.03 sec (2 cycle) fault clearing time

I feel strongly that the use of the flow chart and the task table [Table 130.7(C)(9) from NFPA 70E-2009 or Table 130.7(C)(15) from NFPA 70E-2012] is generally a bad idea. The table is often invalidated because of the notes. For example, note 2 lists a maximum fault current and a maximum clearing time. These values can't be known by looking at a panel. The system must be analyzed to determine these values. If you post a flow chart, I feel you are likely putting (unqualified and even many qualified) people at risk because they likely don't have the information necessary to use the table or chart. The table and chart are useless without the maximum fault current and the maximum clearing time.

There is probably a whole thread about this issue in this forum somewhere.


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PostPosted: Wed May 09, 2012 3:13 pm 
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MIControl wrote:
Please explain the difference between arc-rated and fire retardant. All of our gear now has the ATPV rating, as well as the HRC.


Arc rated means that it is tested according to ASTM 1959. Fire retardant means that it is tested according to another standard. For example many welding jackets have been tested for fire retardancy but not for arc resistance. There are vast differences in how the tests are conducted. Fire retardant tests use a flame and exposure over a significant amount of time to test whether the material burns. Arc rated clothing uses an electric arc and measures over a few seconds at most.

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Even though there is technically no longer a 2*, where is the line transitioning between the steps? My documenation only indicates a minimum arc rating of 8 cal/cm2 for both, but the need for a balaclava for the 2*. In this case, as long as the required ATPV is 12 or below we should be good with the hood up, correct?


This is where we get into "H/RC" and "ATPV". H/RC is a simplified system for rating clothing for use with the tables in 70E. Clothing for each level on the H/RC rating system has to meet a minimum incident energy rating (1=4, 2=8, 3=25, 4=40) to have that H/RC rating. When you do an engineering analysis, you basically don't use H/RC any more. Many folks still use it for convenience (reading the table backwards) but this is not technically correct.

Second, 2* was sort of an argument. Many folks on the 70E committee felt that some "8 cal/cm^2" cases were more risky than others, especially when it came to head injuries. Others wanted to hold onto the non-balaclava "2" category. It's also kind of a hold over from requiring arc rated clothing for switching operations in the utility industry. So for several years the tables had "2*" meaning "the real 8 cal/cm^2" and "2" meaning "8 cal/cm^2 except 4 cal/cm^2 around the head"...or at least that's how it worked in practice. After a revision added the balaclava requirement to "regular 2" as well, then there was no longer a distinction and "old category 2" was dropped. "2*" was renamed to just "2".

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The table is often invalidated because of the notes. For example, note 2 lists a maximum fault current and a maximum clearing time. These values can't be known by looking at a panel. The system must be analyzed to determine these values.


The table is better than nothing. Once you've collected those values, you have enough data to run a very simple analysis such as Lee method. At that point, the table at least theoretically goes out the window. Then we get into the sticky area of considering the likelihood of an arc flash occurring. In this situation the table may still provide value because the current approaches in annex D don't address this.


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