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3RW3 semiconductor motor control unit
SIRIUS System Manual
8-12
GWA 4NEB 430 0999-02b
Auxiliary contacts
3RW30
In the case of frame sizes S0 to S3, the following auxiliary contacts are inte-
grated:
• "ON": When triggered, the latching signal is used for locking by means of a
simple on/off pushbutton (contact designation 13/14).
• "BYPASSED": With the end-of-startup signal, control valves can be
addressed after soft starting of a pump, for example, in order to enable
pumping (contact designation 23/24).
The devices of frame size S00 do not have any auxiliary switches.
3RW31
The 3RW31 does not have any auxiliary contacts.
Soft starting function
Torque-reduced start for three-phase asynchronous motors:
Triggering is two-phase, which means that the current is kept low through-
out the run-up phase. Current peaks such as those that occur in a star-delta
start at the changeover from star to delta are prevented by continuous volt-
age management.
Transient current peaks (inrush peaks) are automatically avoided in each
switch-on procedure by a special control function of the power semiconduc-
tors.
Soft coasting-down
function
The integrated soft coasting-down function prevents the drive coming to an
abrupt halt when the motor is switched off.
3RW30 time ramps
The following graphics show the time ramp of the 3RW30 and the timing
diagram of the auxiliary contacts:
Figure 8-6: Time ramp/timing diagram, 3RW30
The graphic below shows the time ramp of the 3RW3:
Figure 8-7: Time ramp, 3RW31
U
s
U
N
U
t
R on
t
R off
t
t
R on
t
R off
ON
13/14
BYPASSED 23/24
3RW30: Time ramp
Timing diagram of the auxiliary
contacts
U
s
U
N
U
t
t
R1
t
R2