It is currently Sat Sep 23, 2017 6:19 pm



Post new topic Reply to topic
Author Message
ekstra   ara
 Post subject: Mcc cat
PostPosted: Sun Apr 17, 2011 6:02 am 
Offline

Joined: Sat May 01, 2010 2:20 am
Posts: 36
If the main switchgear is lets say a 4 and their feeding breakers to a mcc are 4
will this automatically make the main cb in the mcc be a 4 also ?

480 volt SG
480volt mcc


Top
 Profile Send private message  
Reply with quote  
 Post subject:
PostPosted: Sun Apr 17, 2011 7:13 pm 
Offline

Joined: Fri Oct 30, 2009 9:20 am
Posts: 47
Location: Texas
The impedance of the cable between the switchgear feeder breaker and the MCC could change things. It might reduce the arcing current enough to lower the calculated incident energy, or it might reduce the arcing current enough to move the trip time of the protective device out of the instantaneous range and thereby increase the incident energy. The incident energy at the MCC should be calculated.


Top
 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


Who is online

Users browsing this forum: No registered users and 2 guests


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:  
© 2017 Arcflash Forum / Brainfiller, Inc. | P.O. Box 12024 | Scottsdale, AZ 85267 USA | 800-874-8883