It is currently Wed Dec 13, 2017 12:09 am



Post new topic Reply to topic
Author Message
ekstra   ara
 Post subject: DC Arc Flash Hazard below 100VDC
PostPosted: Mon Nov 27, 2017 12:28 pm 
Offline

Joined: Mon Nov 27, 2017 12:07 pm
Posts: 1
I am working with a client on an Arc Flash study and the client asks me if I can simplify the study for the 956 DC cathodic protection systems they have.

Can I apply worse case incident energies for each rectifier type? I am not sure if this is okay by code since I am not calculating the incident energy for each case.

Is there any cutoff where there would be no risk of arc flash? About half the systems are below 100VDC.

Thanks


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: DC Arc Flash Hazard below 100VDC
PostPosted: Wed Nov 29, 2017 8:01 pm 
Offline
Plasma Level
User avatar

Joined: Tue Oct 26, 2010 9:08 am
Posts: 1820
Location: North Carolina
Kinetrics did some testing for Duke for DC battery systems. They were unable to get above 1.2 cal/cm2 (really even sustain an arc) at 130 VDC with up to 20 kA of available fault current and a 1/4" or less arc gap. That's not a normal arc gap at that voltage. And that is not a typical available fault current even for a substation 60 cell battery. At or below 28 VDC using Hertha Ayrton's equation it's not possible to have an arc at all. So those are both decent data points to use. You can find the Kinetrics/Duke information in some of the Battcon papers that are public (and free).


Top
 Profile Send private message  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 2 posts ] 

All times are UTC - 7 hours


Who is online

Users browsing this forum: No registered users and 1 guest


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:  
cron
© 2017 Arcflash Forum / Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267 USA | 800-874-8883