| Author |
Message |
|
arcflashstudy
|
Post subject: Two pole breakers at 480V  Posted: Wed Oct 27, 2010 11:02 am |
|
Joined: Tue Jun 15, 2010 1:41 pm
Posts: 2
|
|
What is the best approach to calculate incident energy for the two pole breakers at 480V? I came across lighting loads fed from two pole breakers with operating voltage of 480V. Software program that I am using excludes cables having only 2 phases and 2 phase loads from arc flash study.
Would it be accurate to say that all two pole breakers at 480V have Category zero or just exclude them from the study?
|
|
| Top |
|
 |
|
Robertefuhr
|
Post subject: Posted: Wed Oct 27, 2010 11:45 am |
|
| Sparks Level |
 |
Joined: Tue Oct 26, 2010 5:00 pm
Posts: 201
Location: Maple Valley, WA.
|
|
There are equations in IEEE 1584 or NFPA 70E that allow you to calculate the AF energy for line to ground or single phase circuits. When we model these circuits, we will treat them as three phase circuits or breakers. Until there are equations that will allow you to determine the energy levels for these devices, we believe that this is the best method instead of assuming they are category 0.
_________________
Robert Fuhr, P.E.; P.Eng.
PowerStudies
|
|
| Top |
|
|
|
Joules Vernier
|
Post subject: Posted: Thu Apr 28, 2011 1:13 pm |
|
Joined: Tue Apr 12, 2011 6:11 am
Posts: 17
Location: Oregon, USA
|
|
Robert, I take the first line in your preceding comment . . .
"There are equations in IEEE 1584 or NFPA 70E that . . . "
. . . was intended to read . . .
"There are NO equations in IEEE 1584 or NFPA 70E that . . . "
I would agree that under these circumstances, your recommendation certainly seems the most reasonable approach.
|
|
| Top |
|
|
 
|
Page 1 of 1
|
[ 3 posts ] |
|
|
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
|
|
