It is currently Fri Sep 17, 2021 12:32 am



Post new topic Reply to topic
Author Message
ekstra   ara
 Post subject: What is causing downstream breaker to not trip first
PostPosted: Fri Jul 30, 2021 10:43 am 

Joined: Wed Apr 21, 2021 2:44 pm
Posts: 5
Take a look at the attached snapshot for more info. I cannot get "DP2_MCB" to trip before "CB-DP2"
when running a fault injection simulation in ETAP. I think the issue is in the instantaneous trip characteristics of the breakers. However, even if I swap out the make/model of "DP2_MCB" with "CB-DP2" and vice versa, it still has the same problem!

If anyone can figure this out, you are a god

https://ibb.co/j8C1GZD


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: What is causing downstream breaker to not trip first
PostPosted: Mon Aug 02, 2021 2:07 am 

Joined: Mon Jun 05, 2017 8:07 pm
Posts: 15
Hi ,

Can you kindly share the picture of the Sequence viewer? (the one with a magnifier in the toolbar). Please note the time of each breaker. Since they are all in the instantaneous region, the tripping time of all the devices may be the same. Since the time may be same, the animation is following the alphanumeric order of the device ID.

Thank you


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: What is causing downstream breaker to not trip first
PostPosted: Mon Aug 02, 2021 8:45 pm 

Joined: Wed Apr 21, 2021 2:44 pm
Posts: 5
Would you rather have them beautifuly coordinate like this but with instantaneous all disabled:

https://ibb.co/61RTXD9

Or...

Ugly like this but with instantaneous all enabled:

https://ibb.co/hFNrmfZ


Top
 Profile Send private message  
Reply with quote  
 Post subject: Re: What is causing downstream breaker to not trip first
PostPosted: Mon Aug 02, 2021 8:57 pm 

Joined: Wed Apr 21, 2021 2:44 pm
Posts: 5
Raghu wrote:
Hi ,

Can you kindly share the picture of the Sequence viewer? (the one with a magnifier in the toolbar). Please note the time of each breaker. Since they are all in the instantaneous region, the tripping time of all the devices may be the same. Since the time may be same, the animation is following the alphanumeric order of the device ID.

Thank you


here is the pic of the sequence of events

https://ibb.co/xJTSjbH

DP1-MCB & CB-DP2 show the exact same T1 & T2 but notice DP1-MCB If (kA) is lower
So this indicates to me that DP1-MCB would indeed trip last? (if If was to be the same)

I did manage to get them to trip in the right sequence (by tweaking with the breaker settings) and this is still with the instantaneous region all overlapping
https://ibb.co/DwfrW0x


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:  
cron
© 2019 Arcflash Forum / Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267 USA | 800-874-8883