It is currently Mon May 29, 2023 4:49 am

Post new topic Reply to topic
Author Message
ekstra   ara
 Post subject: Arc flash for <125 kVA transformers
PostPosted: Tue Mar 03, 2009 12:43 pm 

Joined: Mon Mar 02, 2009 2:22 pm
Posts: 1
In IEEE 1584, dated 2002, on page 6, fourth paragraph, last sentence – “Equipment below 240 V need not be considered unless it involves at least one 125 kVA or larger low impedance transformer in its immediate power supply.â€

Also on page 25, third paragraph, last sentence within the model and testing discussion – “The arc-flash hazard need only be considered for large 208 V systems: systems fed by transformers smaller than 125 kVA should not be a concern.â€

I am working on Arc flash study for a small electric cooperative. Majority of our transformers are below 125 kVA size. I was wondering if anybody is using this as an option for not considering the arc flash study results for transformer less than 125 kVA.

Any input would be appreciated.


 Profile Send private message  
Reply with quote  
 Post subject:
PostPosted: Fri Jul 24, 2009 8:48 am 

Joined: Wed Jun 24, 2009 4:45 pm
Posts: 41
Location: WA State
I'm also wondering the same thing. If you have a bank of three single phase overhead 100 kVA transformers at 208Y/120, is this to be excluded by IEEE 1584 because it is <240V and no single unit is >125 kVA, or is it to be included in analysis, even though <240V, because the bank is 300 kVA, which is greater than the 125 kVA threshold?

 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

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:  
© 2022 Arcflash Forum / Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267 USA | 800-874-8883