Paul the BIG Finn
Member
- Location
- Ashburn, VA
I have a problem with a short circuit analysis which requires me to the compute the short circuit rating of my synchronizing switchgear and distribution switchgear usi9ng both utility and generator fault contributions because the hospital I am working for uses closed transition ATSs. rbalex, who signs as "Bob, Robert B. Alexander, P.E." wrote a very informative post on that topic:
http://forums.mikeholt.com/showthread.php?t=110459
In the hospital we are working in there are ~80 ATSs distributed throughout the million square foot facility. It is only when a failure occurs in one of the four ATSs located in the Penthouse between Substation #2 and the syncronizing switchgear AND the ATS is in transition between utility and generators with fault contributions coming from both sources that the fault levels of ~85 kAIC occur (the rating of the switchgear is 65 kAIC).
The longer feeder runs to the other ATSs burn off the fault current before it can reach the ATS and return to the switchboard. Right now I am looking at ways to reduce the fault contribution from the utility to these four ATSs. I don't have any experience with current limiting reactors and the ones I found are for use with higher voltages. I need to protect 1,200A and 2,000A ATSs at 480V. Any suggestions?
http://forums.mikeholt.com/showthread.php?t=110459
In the hospital we are working in there are ~80 ATSs distributed throughout the million square foot facility. It is only when a failure occurs in one of the four ATSs located in the Penthouse between Substation #2 and the syncronizing switchgear AND the ATS is in transition between utility and generators with fault contributions coming from both sources that the fault levels of ~85 kAIC occur (the rating of the switchgear is 65 kAIC).
The longer feeder runs to the other ATSs burn off the fault current before it can reach the ATS and return to the switchboard. Right now I am looking at ways to reduce the fault contribution from the utility to these four ATSs. I don't have any experience with current limiting reactors and the ones I found are for use with higher voltages. I need to protect 1,200A and 2,000A ATSs at 480V. Any suggestions?