GE Industrial Solutions BreakMaster Load Interrupter Switch - Manual (Page 26)

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BreakMaster Load Interrupter Switch
Sequence of Operation for Controller MX250-LIS
See GE Zenith document 71R-2000A for more details
When Normal Source voltage or frequency
falls below the preset “Fail” values
(P) Time Delay to start Emergency Source
Time Delay (DT) for closing Normal Switch
S2>S1, SOL Timer start
Time Delay (T) to confirm availability of stable
Normal Source (S1). S2>S1, SOL Timer start
Emergency Source Not Available
Nothing Happens. STOP!
Emergency Source Available
S1>S2, SOL timer starts
Normal Source (S1) Switch Open
No
No Yes
Emergency Switch
stays as is. END!
Yes
Emergency Switch Close Is Normal Source (S1) available?
Emergency Switch Open
Normal Switch Close
When Normal Source returns
(W) Time Delay to open Normal Source to ensure voltage and frequency stabilization
of Emergency Source before transfers
Time Delay (DW) before closing Emergency Switch.
Is Emergency Source (S2) available?
Emergency Source Stop Delay Time (U) – Cool Down
Transfer to Normal
Source (S1)