Some much needed proposals, enhanced task tables, more specific labeling requirements, and some DC guideance.
http://www.necplus.org/Features/Page...70E.aspx?sso=0

Are you sure about that URL? I get "Bad Request", and the three dots look wrong.

Ok, so much for that idea, the forum website is doing something that makes the link unusable.

Try going to this page and clicking on the link in the lower left:

http://www.necplus.org/Features/

The URL in post #3 works well for me.

Unless I'm missing something this isn't much of a "sneak peek". Is there any actual information here?

Teaser would have been a better word, interesting about the bourdaries being added to the tables.

Consider me teased.

It will be interesting to see when it comes out.

DC Arc Flash & Shock Information

I attended the NFPA 70E ROP meeting in Memphis, TN and have some of the information.

The information at this point is coming from White Papers presented and specific information provided by the authors in their Proposal.

The DC table applies to UPS Batteries only, Table Method only. There is a DC arc flash forumula provided as well. There is a DC Shock Approach Boundaries Table, Limited, Restriced and Prohibited Approach Boundaries.

Regards;
Terry Becker, P.Eng.
ESPS Electrical Safety Program Solutions INC.
terry.becker@espsi.ca
403-465-3777

"The DC table applies to UPS Batteries only"

Hi Terry,

It seems like the significant arc flash concerns are with battery banks, like those that provide backup power to 125V/250V relay and breaker trip buses.

Will the DC arc flash formula address battery banks that can supply more significant fault currents?

Thanks

DC Arc Flash and 2012 NFPA 70E

I submitted the original DC Table and then the DC Taskforce modified it to be what you see in the ROP but it wasn't just UPS batteries. It is substation batteries and basically any battery bank.

It doesn't apply to non-battery DC circuits. There is an appendix with DC arc flash calculations for that in the ROP too.

It would be good to have some better guidance in the tables for stationary batteries which have been lacking in the standard.

Hope this helps.

It looks like the ROP (report on proposals) has been posted.
http://www.nfpa.org/aboutthecodes/AboutTheCodes.asp?DocNum=70E

Thanks for the heads up. I set up a post with additional info and the actual PDF in the NFPA 70E section.

Thanks!

Great! The DC Taskforce has a few of the best minds in DC including Dan Doan who wrote one of the original theoretical papers on DC and PK Sen who has done a lot of DC testing, presented a great paper on DC last year and was Project Manager of the NFPA/IEEE Joint Collaborative group. I know Greg Leask of the group was also part of the DC testing for the Joint Collaborative Group. I believe these three in particular have blazed quite a trail for us.

So where does one find this acid protective FR spoken of in note g? Where are Notes 5 and 6?

Terry,

I shot an hour or two yesterday looking for the DC arc flash formula. Can you tell me what page in the pdf it's on? We have high energy DC furnaces here at my plant (50ka and 100 ka), and I'm wanting to get a formula to my arc flash engineer to rough out some flash and shock boundary, and PPE guidance for my electricians working around this equipment. I know it's not in the standard yet, but I'm trying to find anything that may be out there to get this done.

Regards,

Tom Graf

Page 70E 195. It is the older theoretical formula from 2007.

You might want to send him to thsi class, I hear this guy is pretty sharp

http://www.brainfiller.com/documents/HowtoPerformanArcFlashStudy.pdf

I've been trying for some time to attend some of these classes. Getting out of this place is a trick I've not mastered. Big things keep breaking! How about an on line class, Jim?

Wow! Thanks for your interest.

At the moment, I have DVDs as an option for those that can not travel or get away.

Thanks for your support and being part of the ArcFlashForum!

Best Regards