Siemens MICROMASTER 420 Operating Instructions Manual page 73

Issue 04/02
Fault Possible Causes
A0706 CB (communication board) specific
CB warning 7
A0707 CB (communication board) specific
CB warning 8
A0708
CB (communication board) specific
CB warning 9
A0709 CB (communication board) specific
CB warning 10
A0710 Communication with CB
CB communi- (communication board) is lost
cation error
A0711 CB (communication board) reports a
CB configu- configuration error
ration error
A0910 Vdc max controller has been de-
Vdc-max activated, since controller is not
controller de-
capable of keeping DC-link voltage
activated (r0026) within limits (P2172)
Occurs if main supply voltage
(P0210) is permanently too high
Occurs if motor is driven by an
active load, causing motor to
goes into regenerative mode
Occurs at very high load inertias,
when ramping down
A0911
Vdc max controller is active; so ramp-
Vdc-max down times will be increased
controller automatically to keep DC-link voltage
active
(r0026) within limits (P2172)
A0912 Vdc min controller will be activated if
Vdc-min DC-link voltage (r0026) falls below
controller
minimum level (P2172)
active The kinetic energy of the motor is
used to buffer the DC-link
voltage, thus causing
deceleration of the drive!
So short mains failures do not
necessarily lead to an
undervoltage trip
A0920 ADC parameters should not be set to
ADC identical values, since this would
parameters
produce illogical results.
not set Index 0: Parameter settings for
properly
Index 1: Parameter settings for
Index 2: Parameter settings for
A0921 DAC parameters should not be set to
DAC
identical values, since this would
parameters produce illogical results.
not set Index 0: Parameter settings for
properly
Index 1: Parameter settings for
Index 2: Parameter settings for
A0922 No Load is applied to the inverter
No load As a result, some functions may
applied to not work as under normal load
inverter conditions
Low output voltage eg when 0 boost
applied at 0 Hz
MICROMASTER 420 Operating Instructions
6SE6400-5AA00-0BP0
Diagnose & Remedy
See CB user manual
See CB user manual
See CB user manual
See CB user manual
Check CB hardware
Check CB parameters
Check the following:
1. Input voltage (P0756) lies within range?
2. Load must match
In certain cases apply braking resistor
1. Check parameter inverter input voltage
2. Check ramp-down times
Analogue input parameters should not be set to
the same value as each other
output identical
input identical
input do not correspond
to ADC type
Analogue Output parameters should not be set to
the same value as each other
output identical
input identical
output do not correspond
to DAC type
1. Check that load is applied to the inverter
2. Check motor parameters correspond to motor
3. As a result, some functions may not work
attached
correctly, because there is no normal load
condition
6 Troubleshooting
Reac-
tion
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