Siemens SINAMICS S120 Function Manual page 287

Signal fault
n + 2n
max
Synchronous speed
n
set ,converter
r 1261 bit 0
r 1261 bit 1
Fig. 4-34 Signal diagram, bypass without synchronization, selection "bypass for fault"
When the drive converter fault occurs, the drive initially responds by inhibiting the
pulses; changeover is initiated after the bypass time (p1264) has expired: Contac-
tor K1 is opened (r1261.0 = 0) and the system waits for the bypass deadtime to
expire (p1262 – this must correspond to at least the motor de-excitation time. Con-
tactor K2 is then closed (r1261.1 = 1) which means that the motor is directly con-
nected to the line supply.
After the fault is no longer present, the system waits for the debypass time time
(p1263), and then the drive converter can again feed the motor. To do this, contac-
tor K2 is opened (r1261.1 = 0) and after the bypass deadtime (p1262), contactor
K1 is closed (r1261.0 = 1). The converter is connected to the motor – that is gener-
ally still rotating – and normal operation is resumed.
© Siemens AG 2006 All Rights Reserved
SINAMICS S120 Function Manual, 03/2006 Edition
1
0
p1264
n
Slip
1
0
1
0
p1262
p 1263
n
Motor
p1262
Extended Functions
Bypass (vector)
t
n
Flying restart
t
t
t
4-287