Siemens SINAMICS G120 List Manual page 1084

4 Faults and alarms
4.2 List of faults and alarms
A07402 (N) Drive: DC link voltage minimum controller active
Message class: Application/technological function faulted (17)
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 configuration (vector control)), p1280 (Vdc
controller configuration (U/f))
Remedy: The alarm disappears when power supply returns.
F07404 Drive: DC link voltage monitoring Vdc_max
Message class: DC link overvoltage (4)
Reaction: OFF2 (NONE, OFF1, OFF3)
Acknowledge: IMMEDIATELY
Cause: The monitoring of the DC link voltage p1284 has responded (only U/f control).
Remedy: - check the line supply voltage.
- check the braking module.
- adapt the device supply voltage (p0210).
- adapt the DC link voltage monitoring (p1284).
F07405 (N, A) Drive: Kinetic buffering minimum speed fallen below
Message class: Application/technological function faulted (17)
Reaction: OFF2 (IASC/DCBRK, 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))
F07406 (N, A) Drive: Kinetic buffering maximum time exceeded
Message class: Application/technological function faulted (17)
Reaction: OFF3 (IASC/DCBRK, NONE, OFF1, OFF2, STOP2)
Acknowledge: IMMEDIATELY
Cause: The maximum buffer time (p1255 and p1295 for vector drives with U/f control) has been exceeded without the line
supply having returned.
Remedy: Check the time threshold for Vdc-min controller (kinetic buffering) (p1255, p1295).
See also: p1255 (Vdc_min controller time threshold), p1295 (Vdc_min controller time threshold (U/f))
A07409 (N) Drive: U/f control, current limiting controller active
Message class: Application/technological function faulted (17)
Reaction: NONE
Acknowledge: NONE
Cause: The current limiting controller of the U/f control was activated because the current limit was exceeded.
Remedy: The alarm is automatically withdrawn after one of the following measures:
- increase current limit (p0640).
- reduce the load.
- slow down the ramp up to the setpoint speed.
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SINAMICS G120 CU250S-2 Control Units
List Manual, 09/2017, A5E33842890