It is currently Mon Sep 27, 2021 3:16 pm



Post new topic Reply to topic
Author Message
ekstra   ara
 Post subject: Lables for Panels with 120V single phase and less
PostPosted: Thu Mar 30, 2017 9:14 am 

Joined: Tue Nov 04, 2014 5:53 am
Posts: 16
I am looking for guidance on where / how to create labels for 120V single phase and less panels for which no arc flash hazard exists... It seems wise to communicate with a label - the voltage / shock PPE and boundaries and make clear that no AF PPE hazard or AF boundary exists - rather than leave the panel unlabeled for a worker to wonder why there is no label. Any experience with this? Thanks in advance!


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Lables for Panels with 120V single phase and less
PostPosted: Thu Mar 30, 2017 11:40 am 
Sparks Level
User avatar

Joined: Fri Jul 08, 2016 10:01 am
Posts: 227
Location: Indiana
I don't know if it's completely kosher or not but in instances like you describe I use a generic version our normal labels except for incident being calculated I have manually changed them to say "Less than 8 cal/cm^2" with a PPE description of category 2.

Our electricians only carry level 2 and level 4 PPE to keep things as simple as possible.

_________________
SKM jockey for hire


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Lables for Panels with 120V single phase and less
PostPosted: Fri Mar 31, 2017 10:33 am 
Plasma Level
User avatar

Joined: Tue Oct 26, 2010 9:08 am
Posts: 2174
Location: North Carolina
bbaumer wrote:
I don't know if it's completely kosher or not but in instances like you describe I use a generic version our normal labels except for incident being calculated I have manually changed them to say "Less than 8 cal/cm^2" with a PPE description of category 2.

Our electricians only carry level 2 and level 4 PPE to keep things as simple as possible.


That could be a hassle with the face shield/balaclava requirement. It's easier to work if you set your lower threshold at a level where the face shield is eliminated. 6-10 cal/cm2 is usually the "minimum" for arc resistant PPE because this is an inherent property of the underlying material...a long sleeve cotton T-shirt as long as it doesn't ignite protects up to 6 cal/cm2.

I would caution against the concept that "120 circuits" are totally hazard free. This may be true 120 VAC circuits and even 125 VDC circuits. Starting at around 200-300 VAC there is an arc flash hazard, although it is pretty low. So 120 VAC isn't really a problem but 240/120 and even 208/120 might be. IEEE Standard C2 gives guidance of wearing arc flash PPE only (shirts and pants, minimum ATPV 4). OSHA also recommends arc resistant PPE for distribution workers in OSHA 1910.269.


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Lables for Panels with 120V single phase and less
PostPosted: Mon Apr 03, 2017 7:07 am 

Joined: Tue Jan 04, 2011 9:33 am
Posts: 9
We label two ways - one for the IEEE exception and a standard AF Label for 120/208. If we need to do an analysis for 480 systems it is easy to go downstream one more level to determine the AF energy for the line side of those panels. It is easier and takes less time to label these low AF energy panels with some type of label rather to answer the question of why they are not labeled. Besides it is safer.

Shock hazard PPE still has to be worn and industrial electrician AF wear is standard for the industry - there is latitude to wear site specific PPE. But if you are at a site that buys the PPE for those employees that may be in contact with energized electrical parts and pieces the AF rated PPE is not much more expensive. Appendix H in NFPA 70 E 2015 has a good recommendation for site specific PPE. And after studying it for a while the only real difference between AF industrial wear and level 2 is the arc flash shield and the balaclava.


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Lables for Panels with 120V single phase and less
PostPosted: Mon Apr 03, 2017 7:41 am 
Sparks Level

Joined: Thu Oct 18, 2007 7:10 pm
Posts: 263
Location: NW USA
We have labelled single phase panels, 240V and below as PPE category 1, per Table 130.7(C)(15)(A)(b). As there is no lesser category, nor rating allowed for 120V panels, this would seem to cover it.

(As most of the systems are modeled at this point, an Arc Flash Calculation is an expedient way to verify the arc flash exposure at these locations is not above 4 Cal/cm2; however, when such is discovered, than the higher PPE category is listed. It remains problematic in my mind that NFPA 70E states we cannot list both PPE category and Calories)


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Lables for Panels with 120V single phase and less
PostPosted: Mon Apr 03, 2017 8:48 am 
Sparks Level
User avatar

Joined: Tue Nov 12, 2013 6:31 am
Posts: 238
Location: Port Huron, Michigan
Gary B wrote:
We have labelled single phase panels, 240V and below as PPE category 1, per Table 130.7(C)(15)(A)(b). As there is no lesser category, nor rating allowed for 120V panels, this would seem to cover it.

(As most of the systems are modeled at this point, an Arc Flash Calculation is an expedient way to verify the arc flash exposure at these locations is not above 4 Cal/cm2; however, when such is discovered, than the higher PPE category is listed. It remains problematic in my mind that NFPA 70E states we cannot list both PPE category and Calories)


That means you are making it mandatory for your workers to wear a face shield when working in a 120V breaker panel.


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Lables for Panels with 120V single phase and less
PostPosted: Mon Apr 03, 2017 10:00 am 

Joined: Mon Jul 23, 2012 10:36 am
Posts: 8
When the arc flash hazard has been calculated to be <1.2 cal/cm2, we label 208V and 480V equipment with a label that along with the shock hazard information includes; "Arc Flash Hazard: <= 1.2 cal/cm2 at 18". Flash Protection Boundary ___". "
We have a genic label that has 18" for the boundary or we will have a write on label where we fill in the actual boundary distance calculated ex. 7".


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Lables for Panels with 120V single phase and less
PostPosted: Mon Apr 03, 2017 10:57 am 
Sparks Level
User avatar

Joined: Tue Oct 26, 2010 5:00 pm
Posts: 196
Location: Maple Valley, WA.
We recommend that you put a label on the equipment even if it is less than 1.2 Cal/cm2. The shock hazard still exists even though the Arc Flash is low. Not applying an AF label on some equipment will lead to confusion and doubt.

We use SKM for most of our studies and we use their IEEE option for locations where where one transformer less than 240V and 125 KVA. For those locations, the AF energy on the label will be 1.2 Cal/cm2. We still print a label for these locations.

_________________
Robert Fuhr, P.E.; P.Eng.
PowerStudies


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Lables for Panels with 120V single phase and less
PostPosted: Thu Jun 01, 2017 3:32 pm 

Joined: Tue May 30, 2017 11:10 am
Posts: 2
I have a customer that only wants short circuit and arc flash down to the 480V level, can I complete this and not be liable for anything down stream?


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Lables for Panels with 120V single phase and less
PostPosted: Fri Jun 02, 2017 10:02 pm 
Plasma Level
User avatar

Joined: Tue Oct 26, 2010 9:08 am
Posts: 2174
Location: North Carolina
Just insert it in the summary of the extent of the study. You don't analyze the utility beyond given data. Nobody can do "everything".


Top
 Profile Send private message  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 10 posts ] 

All times are UTC - 7 hours


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Jump to:  
© 2019 Arcflash Forum / Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267 USA | 800-874-8883