Siemens CU240B-2 Parameter Manual page 694

Faults and Alarms
List of Faults and Alarms
F07331 Flying restart: Function not supported
Reaction: OFF2 (NONE, OFF1)
Acknowledge: IMMEDIATELY
Cause: It is not possible to power up with the motor rotating (no flying restart). In the following cases, the "flying restart"
function is not supported:
Perm.-magnet synch. motors (PEM): operation with U/f char. and sensorless vector control.
Remedy: Cancel the "flying restart" function (p1200 = 0).
A07400 (N) Drive: DC link voltage maximum controller active
Reaction: NONE
Acknowledge: NONE
Cause: The DC link voltage controller has been activated because the upper switch-in threshold has been exceeded (r1242,
r1282).
The ramp-down times are automatically increased in order to maintain the DC link voltage (r0070) within the
permissible limits. There is a system deviation between the setpoint and actual speeds.
When the DC link voltage controller is switched out (disabled), this is the reason that the ramp-function generator
output is set to the speed actual value.
See also: r0056 (Status word, closed-loop control), p1240 (Vdc controller or Vdc monitoring configuration (vector
control)), p1280 (Vdc controller or Vdc monitoring configuration (U/f))
Remedy: If the controller is not to intervene:
- increase the ramp-down times.
- switch-off the Vdc_max controller (p1240 = 0 for vector control, p1280 = 0 for U/f control).
If the ramp-down times are not to be changed:
- use a chopper or regenerative feedback unit.
A07401 (N) Drive: DC link voltage maximum controller de-activated
Reaction: NONE
Acknowledge: NONE
Cause: The Vdc_max controller can no longer maintain the DC link voltage (r0070) below the limit value (r1242, r1282) and
was therefore switched out (disabled).
- the line supply voltage is permanently higher than specified for the power unit.
- the motor is permanently in the regenerative mode as a result of a load that is driving the motor.
Remedy: - check whether the input voltage is within the permissible range.
- check whether the load duty cycle and load limits are within the permissible limits.
A07402 (N) Drive: DC link voltage minimum controller active
Reaction: NONE
Acknowledge: NONE
Cause: The DC link voltage controller has been activated as the lower switch-in threshold has been undershot (r1246,
r1286).
The kinetic energy of the motor is used to buffer the DC link. The drive is therefore braked.
See also: r0056 (Status word, closed-loop control), p1240 (Vdc controller or Vdc monitoring configuration (vector
control)), p1280 (Vdc controller or Vdc monitoring configuration (U/f))
Remedy: The alarm disappears when power supply returns.
F07405 (N, A) Drive: Kinetic buffering minimum speed not reached
Reaction: OFF2 (IASC/DCBRAKE, NONE, OFF1, OFF3, STOP2)
Acknowledge: IMMEDIATELY
Cause: During kinetic buffering the speed fell below minimum speed (p1257 or p1297 for vector drives with U/f control) and
the line supply did not return.
Remedy: Check the speed threshold for the Vdc_min controller (kinetic buffering) (p1257, p1297).
See also: p1257 (Vdc_min controller speed threshold), p1297 (Vdc_min controller speed threshold (U/f))
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SINAMICS G120 / Control Units CU240B/E-2 Parameter Manual (LH11), 01/2011
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