Siemens SINAMICS S120 Function Manual page 280

Extended Functions
Bypass (vector)
Transfer operation
Motor
connected to the
drive converter
p1266
Bypass command
r1261 .2
Synchronization requested
(from the bypass function)
r3819 .2
"Synchronism reached"
r1261 .1
Close contactor K 2
p1269 .1
Contactor K 2 closed
r1261 .0
Close contactor K 1
p1269 .0
Contactor K 1 closed
Fig. 4-31 Signal diagram, bypass with synchronization with overlap
The motor is transferred to the line supply
(the drive converter controls contactors K1 and K2):
S The initial state is as follows: Contactor K1 is closed, contactor K2 is open and
the motor is fed from the drive converter.
S The control bit "bypass command" (p1266) is set (e.g. from the higher-level
automation).
S The bypass function sets the control word bit "synchronizing" (r1261.2).
S The bit is set which means that while the drive converter is operational, the
synchronizing operation "transfer the motor to the line supply" is initiated.
S After the motor has been synchronized to the line supply frequency, voltage and
phase position, the synchronization algorithm signals this state (r3819.2).
S The bypass mechanism evaluates this signal and closes contactor K2 (r1261.1
= 1). The signal is internally evaluated – BICO wiring is not required.
S After contactor K2 has signaled back the "closed" state (r1269[1] = 1), contactor
K1 is opened and the drive converter inhibits the pulses. The drive converter is
in the "hot standby" state.
S If the on command is withdrawn in this phase, the drive converter changes into
the basic standby state. If the appropriate contactors are being used, the drive
converter is isolated from the line supply and the DC link is discharged.
4-280
Changeover operation Motor connected
drive converter – line to the line supply
supply
Changeover
operation line
supply – drive
converter
© Siemens AG 2006 All Rights Reserved
SINAMICS S120 Function Manual, 03/2006 Edition
Motor connected
to the drive
converter