Help location a thread -Coordination Time Interval

[UtilityGy]

Gentleman,

I am trying to find a thread that talks about CTI between main secondary breaker and feeder breaker in a medium voltage system. I recall very well I saw it here but am having a hard time recollecting the exact name.

Thanks

 

[AMBMI]

Did you try searching for "grading margin" too?
You should find something useful (i.e. 2nd finding in the list)

 

[Paszt]

No need to jump through hoops:

http://www.eng-tips.com/viewthread.cfm?qid=213992