NFPA70e Analysis requirement

[Boltbreaker2014]

I supervise electricians in an industrial environment. The facility has about 626 electrical enclosures ranging from 120VAC outlets to Main Dist. Gear of 2500 amps 480VAC. My employer has been reluctant to pay for an AF analysis due to the cost. I have responded by requiring my electricians to gear up with AF gear to even open an enclosure of any kind. Pissing them off and slowing tasks down. I am not willing to trade their safety for speed or convenience. This issue came to a head recently with an OSHA visit. OSHA was very happy with the administrative controls I have put in place but still wrote a finding that we were not in compliance due to labeling issues. My reading of NFPA70e 2012 indicates that an study must be performed on every enclosure to indicate the incident energy, approach distance and level of gear requirement. My safety person (who is very political and whose budget a study would come out of) claims that the tables in 2012 are sufficient to determine the three key items. I cannot see how a 480VAC, 30 amp disconnect is the same as a 1500amp machine control panel as far as available incident energy goes.

Please help me understand his position or help me gain ammo for a AF study done the specified way. Thanks!

Nice forum. Wish I had found it sooner!

 

[jim dungar]

Technically, NFPA70E does not require you to have a study done, it requires you to analyze the equipment and offers the Task Tables as one method.

However, NFPA70E, and therefore OSHA, do specifically require labels on the equipment.

 

[Boltbreaker2014]

Technically, NFPA70E does not require you to have a study done, it requires you to analyze the equipment and offers the Task Tables as one method.

However, NFPA70E, and therefore OSHA, do specifically require labels on the equipment.

All of the panels/enclosures in the Plant have this label down to disconnect level along with a voltage label:



OSHA said that that is not enough. That we need the three key listings as seen here:




How do you arrive at the second label with just "tables" and remain sure that the incident energy is correctly calculated?

 

[GoldDigger]

In theory the tables give you the hazard category which in turn determined the PPE required without having to list an incident energy.
I can see the inspectors concern with a label that tells you to use appropriate PPE but does not tell you what the appropriate PPE is.
There should be an intermediate label option that lists the table category and PPE without showing details that could come only from a full study.
The second label you shoe has a space for the energy protection level the PPE must meet according to the category, not the calculated energy level for that specific equipment.
With that clarification, I agree with the inspector.

Tapatalk!

 

[jim dungar]

How do you arrive at the second label with just "tables" and remain sure that the incident energy is correctly calculated?

Typically you can't.

I can see the inspectors concern with a label that tells you to use appropriate PPE but does not tell you what the appropriate PPE is

A 'qualified individual' knows how to chose the appropriate PPE. There is nothing wrong with having a poster in the 'electric shop' or switchgear room.
The listing of what constitutes appropriate PPE often simply clutters up a label. In fact most labels, I have seen, have only an abbreviated list of required PPE components on them.

When was the last time you saw specific PPE requirements on a 'confined entry space' label, or on one for hazardous materials?

 

[GoldDigger]

I agree that the choice of specific PPE components could be covered by informational posters, etc. elsewhere.
But do you also feel that the tables can be posted somewhere or that the table-derived category should be posted at the equipment to inform the worker in choosing appropriate PPE?

Tapatalk!

 

[joebell]

Most of the labels that I have seen installed provide you with the HRC level. As discussed in an earlier post a qaulified person would know where to obtain the proper PPE from this information.

In regards to the tables found in 70E, the PPE listed is based on specific conditions found in the footnotes to the table. If your equipment falls in the footnotes then you are good to go. Unfortunately most do not therefore an AFHA should be done.

Another note a little off topic please know that even properly selected PPE will produce injury in the form of second degree burn if there were to be a flash and that there is nothing available to protect against the pressure from the blast.


Good Luck

 

[jim dungar]

... there is nothing available to protect against the pressure from the blast..

And there is no direct correlation between incident energy and blast wave.
Do not assume low incident energy means no blast (warped and blown open doors are common even when the protective device operates quickly). Also high incident energy may be due to low arcing currents resulting in long clearing times (think arc welding).

 

[Boltbreaker2014]

Thank you to all for the great responses. It seems that I can use the tables and see if my situation fits. I really appreciate the thoughts on clearing times and blast wave. Sobering issues to ponder

 

[Samuel Beckley]

Is it safer to have the arc flash analysis done or to use the tables? My.company HSE person put cat II labels on all enclosures and gave everyone PPE for CatII. Is this goid enough?

Sent from my SCH-I605 using Tapatalk

 

[zog]

To use the tables you have to ensure you fall within the limits of each type of equipment listed in the notes, which means you need to know the available fault current and clearing time of the OCPD. Ignoring the notes is dangerous and does not meet the 70E requirements.

 

[aelectricalman]

Heads a little cloudy today. Hope I am not restating something already said. If you are just going with the blanket approach, you need to keep in mind that anything above 40 calorie will not be acceptable to operate energized. Using this blanket approach can get you in trouble, if you don't have a way to determine the incident energy on a piece of equipment that otherwise would be classified as the highest risk class.