TAVRIDA ELECTRIC ISM Shell_2 Series, Руководство по применению

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Fast Transfer Switching
Sensitive loads in industrial processes are often configured with a secondary primary feed from the utility for
backup and reserve power. For sectors such as oil & gas, slow transfer times from traditional switching solutions
result in motor stoppages and lost production time while processes are brought back on-line.
The high closing and opening speeds of the ISM15_Shell_2 series allow for a packaged solution. The VCB_FTS
system is comprised of specially selected ISM15_Shell_2 breakers, control modules with a faster command
recognition speed, and optional automatic transfer relays.
Transfer speed can be delineated by two transition types:
1. Closed transition - the backup power line is connected by closing the breaker before the main line is interrupted
(make before break).
2. Open transition - the backup power line is connect by closing the breaker after the main line is interrupted (break
before make).
The timing of the system can therefore be broken down by the following table, using the SEL-451 relay as an
example of total timing calculation:
Product Parameters Designation Response Time
ISM15_Shell_2 opening time (including CM)
Topen 12 ms
ISM15_Shell_2 interrupting time (including CM) Tinterrupt 20 ms
ISM15_Shell_2 closing time (including CM) Tclose 26 ms
SEL-451 open phase detection logic trip time Tsel451 10 ms
Closed transition with SEL-451 open phase detec-
tion logic trip time
T Tclose 36 ms
Open transition with SEL-451 open phase detec-
tion logic trip time
T Topen 48 ms
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