Closed Transition
Closed Transition
(OP)
Electrical System: (3) 2000kW Gen sets located on floor 1, (4) networked 2500kVA transformers on the basement. The Generators and service entrance transformers feed the emergency equipment via an ATS on the 8th floor.
My question is to transfer the power from commercial to emergency I use an open transition to supply the load, but on return to commercial I want a closed transition from Generators to Commercial. I want to use the woodward GCP-31 governor for my gen's. To complete the closed transistion I must sync the generators that are supplying emergency power to the available commercial power. Now since the ATS are located on the 8th floor do I install CT's and PT's at the service entrance switchgear and have those talk to the woodward or should I do all this sync'n at the ATS. There is considerable distance between the ATS's and the service entrance gear and the voltage at the service entrance gear vs. the voltage at the ATS under load.
It seems resonable to do this - a closed transition on the return to normal at the 8th floor ATS, but so far I am the only ones who think so...
My question is to transfer the power from commercial to emergency I use an open transition to supply the load, but on return to commercial I want a closed transition from Generators to Commercial. I want to use the woodward GCP-31 governor for my gen's. To complete the closed transistion I must sync the generators that are supplying emergency power to the available commercial power. Now since the ATS are located on the 8th floor do I install CT's and PT's at the service entrance switchgear and have those talk to the woodward or should I do all this sync'n at the ATS. There is considerable distance between the ATS's and the service entrance gear and the voltage at the service entrance gear vs. the voltage at the ATS under load.
It seems resonable to do this - a closed transition on the return to normal at the 8th floor ATS, but so far I am the only ones who think so...






RE: Closed Transition
Most utility co. will require a watchdog timer and controls to externally separate the two sources, if they fail to separate at the ATS.
Rafiq Bulsara
http://www.srengineersct.com