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1
Stand-by feeder voltage
2
Busbar voltage
3
Voltage difference between stand-by and busbar voltage
4
Main feeder current
5
Stand-by feeder current
6
Transfer duration
Figure 945: Vector diagram of a transfer at the 1
st
phase coincidence
U
Stand-by
Stand-by feeder voltage
U
Busbar
Busbar voltage
φ
Angle between stand-by voltage and busbar voltage
dφ/dt
Angle speed between stand-by voltage and busbar voltage
Blue area
Connection window (dependent upon breaker closing time and dφ/dt
If
DISA_RUN
input is active, transfer is not allowed to complete until input is
deactivated.
When 1
st
phase transfer is completed, this is indicated with
COMPL_1ST_PH
output.
Control functions
1MRS759142 F
1778
REX640
Technical Manual