A0710 cb communications error, A0711 cb communications error, A0910 vdc-max controller disabled/switched-out – Siemens 440 User Manual
Page 318: A0911 vdc-max controller active, A0912 vdc-min controller active

Faults and Alarms
Issue 01/06
MICROMASTER 440 Parameter List
318
6SE6400-5BB00-0BP0
A0707 CB alarm 8
Cause
- CB-(Communications
module)-specific
Diagnosis & Remedy
-
refer to the CB User Manual
A0708 CB alarm 9
Cause
- CB-(Communications
module)-specific
Diagnosis & Remedy
-
refer to the CB User Manual
A0709 CB alarm 10
Cause
- CB-(Communications
module)-specific
Diagnosis & Remedy
-
refer to the CB User Manual
A0710 CB communications error
Cause
-
loss of communications with the CB (communications module)
Diagnosis & Remedy
-
check the CB hardware
A0711 CB communications error
Cause
-
CB (communications module) signals a communications error.
Diagnosis & Remedy
-
check the CB parameters
A0910 Vdc-max controller disabled/switched-out
Cause
-
Vdc max controller was de-activated, as it was not able to keep the DC link voltage (r0026) within the
limit values (refer to r0026 and P1240).
This occurs,
-
if the line supply voltage is permanently too high.
-
if the motor is driven by an active load, which means that the motor goes into regenerative operation.
-
while decelerating (short down-ramps P1121) for extremely high load torques
Diagnosis & Remedy
Please check the following:
-
is the input voltage (P0756) within the permissible range ?
-
are load duty cycle and load limits within the permissible limits ?
A0911 Vdc-max controller active
Cause
-
Vdc max controller is active
-
the ramp-down times are automatically increased in order to keep the DC link voltage (r0026) within the
limit values (refer to r0026 and P1240).
A0912 Vdc-min controller active
Cause
-
Vdc min controller is activated, if the DC link voltage (r0026) falls below the minimum value (refer to
r0026 or P1240).
-
the kinetic energy of the motor is used to buffer the DC link voltage and therefore to slow down the
drive.
-
therefore brief line failures no longer automatically result in an undervoltage trip.