It is currently Thu May 06, 2021 4:58 pm



Post new topic Reply to topic
Author Message
ekstra   ara
 Post subject: Etap Star Auto-Eval Error
PostPosted: Wed Apr 21, 2021 2:47 pm 

Joined: Wed Apr 21, 2021 2:44 pm
Posts: 2
Any experienced Etap users here understand what the heck the problem is with this Star Auto-Eval?

Keeps saying "trip curve crosses" damage curve for a 20A breaker protecting 12awg cable.

thanks

Picture:
https://ibb.co/1656NXk


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Etap Star Auto-Eval Error
PostPosted: Thu Apr 22, 2021 1:25 pm 

Joined: Wed Jul 12, 2017 6:06 am
Posts: 35
Looks to me if the fault was at Bus 36, the cable would only see 1.3 kA fault current and would be OK. Now if the fault was in the cable it could see more, but at that point the cable is damaged already so would it matter?


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Etap Star Auto-Eval Error
PostPosted: Thu Apr 22, 2021 3:45 pm 

Joined: Wed Apr 21, 2021 2:44 pm
Posts: 2
Good point. It's strange the software is showing the source fault value for this cable considering it will only ever see the load fault.


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: Etap Star Auto-Eval Error
PostPosted: Mon Apr 26, 2021 7:51 am 

Joined: Mon Feb 23, 2015 10:19 am
Posts: 8
What if the fault were in the beginning of the cable run vs the end.
Then the fault current will be a lot higher than 1.313kA. It might be closer to the 39kA.
Then the tripping by the upstream breaker will not prevent the cable from seeing currents beyond their damage curve.

I think the problem is that there is too much fault current for #12 wire.
Options: increase wire size or decrease Fault Current.


Top
 Profile Send private message  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 4 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