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Arc Terminator
https://brainfiller.com/arcflashforum/viewtopic.php?f=12&t=523		 Page 1 of 1
Author:  LarryJo [ Tue Jun 30, 2009 1:01 pm ]
Post subject:  Arc Terminator
My client has purchased the Arc Terminator from Square D.
Using the software, the model shows a category 3 rating for the switchgear that has the terminator. I am not able to model the terminator so the category 3 is based off just the normal operation trip time. Since the incident energy is related to trip time, can I take the incident energy at the trip time without the terminator and ratio it to the 1/4 cycle time with the terminator to determine the incident energy with the terminator?
If I do this, should the labels have the new category on them even though it would only apply when the terminator is operational? My understanding is that the labels should indicate the category rating when someone is working on the equipment live, but in this case the terminator will still be operational even if the doors are open and someone is working on it. The vendor tells us that with the terminator, the Arc Flash rating is a category 0 but that is how they are selling it and i wanted to get some advice from some of you guys. Not that I do not believe them, it would just make me feel better is someone else out there has addressed this.
Author:  Jim Phillips (brainfiller) [ Wed Jul 01, 2009 6:53 am ]
Post subject: 
Deja Vu. :cool:
This sounds similar to arc resistant switchgear a few years ago. It was designed to contain the arc and be "Category 0" regardless of what the calculations indicated. Most people would accept the category 0. However until recently, 70E never officially acknowledged the arc resistant design.

Sounds like we're going down that road again with the Arc Terminator design. I would make sure you get something in writing from the manufacturer to back up (CYA) the category 0 rating. I'm not sure I would change the arc flash model though.

I know there are a few switchgear guys that hang out here as well. Maybe they will have some other good info to add.
Author:  LarryJo [ Wed Jul 01, 2009 7:06 am ]
Post subject: 
Thanks

I did get some documentation from the vendor that verifies the category 0 claim. I just need to make the model print me a label that has that category on it.
Author:  McFlash [ Wed Jul 01, 2009 9:41 am ]
Post subject: 
Not sure what software package you are using, but in easypower you can do it quite easy. There are a couple of ways, one way is to just force the bus to a #0 this will come out to #0 every time you run calculations, the other way is to set a user defined clearing time....I think you can only go down to .01 at a min but that should give you a good idea if you are really a #0 or not. Hope this helps.
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