It is currently Thu Sep 16, 2021 12:51 pm



Post new topic Reply to topic
Author Message
ekstra   ara
 Post subject: XF Secondary - HCB with Barrier?
PostPosted: Fri Jul 23, 2021 4:46 pm 

Joined: Fri Jul 23, 2021 3:20 pm
Posts: 2
Hi All,

I am completing an AFHA of a site that has numerous 3MVA, 35/0.48 kV transformers. These transformers have split secondary bushings on either side. There are also two cabinet doors for a single set of bushings. Between the doors there is a small, permanent section of the enclosure that effectively acts as a barrier at the end of the horizontal electrodes. See attached drawing snip and photo.

What are your thoughts on electrode configuration per IEEE-1584-2018? HCB seems most appropriate. However, I am thinking the barrier would block a substation portion of the AF event and any personnel in front of either access panel would experience some reduced amount of IE due to their proximity and position for access. In other words, the blast would not be directed at them.

I'd appreciate any feedback.

-Andrew


Attachments:
XF Electrode Config Q.pdf [232.03 KiB]
Downloaded 70 times
Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: XF Secondary - HCB with Barrier?
PostPosted: Fri Aug 13, 2021 2:47 pm 

Joined: Fri Jul 23, 2021 3:20 pm
Posts: 2
*substantial portion

Any opinions on this one?


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: XF Secondary - HCB with Barrier?
PostPosted: Mon Aug 16, 2021 6:54 am 

Joined: Mon Dec 03, 2018 11:09 am
Posts: 8
It's closest to VCBB if the worker is at or near the plane of entry into the cabinet. Right in front, that panel will block a lot. But if you're at the side, the panel may direct the fireball towards you.

This is a tricky case. The barrier is likely to make things worse, purely because it'll make it more likely that the arcs can sustain themselves.


Top
 Profile Send private message  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 3 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:  
© 2019 Arcflash Forum / Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267 USA | 800-874-8883