Siemens MICROMASTER 440 Operating Instructions Manual page 150

3 Functions
V
DC_max
r0056 Bit 14
Fig. 3-62
On the other hand, if the Vdc_max controller increases the output frequency (e.g.
for a steady-state regenerative load), then the Vdc_max controller is disabled by an
internal drive inverter monitoring function and warning A0910 is output. If the
regenerative load continues, the drive inverter is protected using fault F0002.
In addition to controlling the DC link (closed-loop), the Vdc_max controller supports
the stabilizing processes of the speed at the end of an acceleration phase. This is
especially the case if there is an overshoot and the motor therefore briefly goes into
regenerative operation (damping effect).
NOTE
If the DC link voltage exceeds the power-on threshold r1242 (switch-on level of
Vdc_max.) of the Vdc_max controller in the "Ready" state, then the Vdc_max
controller is de-activated and warning A0910 is output.
Cause:
Remedy:
If, in the "Run" state, the DC link voltage exceeds the power-on threshold r1242
and if the Vdc_max controller output is limited by parameter P1253 for approx.
200 ms, then the Vdc_max controller is de-activated and warning A0910 and,
where relevant, fault F0002 are output.
Cause:
Remedy:
150
V
DC
r1242
-controller active
1
0
f
Vdc_max controller
The line supply voltage does not match the application situation.
Refer to parameters P1254 and P0210.
Line supply voltage P0210 or ramp-down time P1121 too low
The moment of inertia of the driven load is too high
Refer to parameters P1254, P0210, P1121
Use a braking resistor
A0911
f
act
f
set
MICROMASTER 440
6SE6400-5AW00-0BP0
Issue 10/03
t
t
t
Operating Instructions