Siemens SINAMICS G120 Manual page 686

Faults and Alarms
List of Faults and Alarms
F07800 Drive: No power unit present
Reaction: NONE
Acknowledge: IMMEDIATELY
Cause: The power unit parameters cannot be read or no parameters are stored in the power unit.
Connection between Control Unit and power unit was interrupted or is defective.
Note:
This fault also occurs if an incorrect topology was selected in the commissioning software and this parameterization
is then downloaded to the Control Unit.
See also: r0200 (Power unit code number actual)
Remedy: - connect the data line to power unit and restart the CU (POWER ON).
- check or replace the CU.
- Check the cable between the CU and power unit.
- after correcting the topology, the parameters must be again downloaded using the commissioning software.
F07801 Drive: Motor overcurrent
Reaction: OFF2 (NONE, OFF1, OFF3)
Acknowledge: IMMEDIATELY
Cause: The permissible motor limit current was exceeded.
- effective current limit set too low.
- current controller not correctly set.
- U/f operation: Up ramp was set too short or the load is too high.
- U/f operation: Short-circuit in the motor cable or ground fault.
- U/f operation: Motor current does not match current of power unit.
- Switch to rotating motor without flying restart function (p1200).
Note:
Limit current = 2 x minimum (p0640, 4 x p0305 x p0306) >= 2 x p0305 x p0306
Remedy: - check the current limits (p0640).
- vector control: Check the current controller (p1715, p1717).
- U/f control: Check the current limiting controller (p1340 ... p1346).
- increase the up ramp (p1120) or reduce the load.
- check the motor and motor cables for short-circuit and ground fault.
- check the motor for the star-delta configuration and rating plate parameterization.
- check the power unit and motor combination.
- Choose "flying restart" function (p1200) if switched to rotating motor.
F07802 Drive: Infeed or power unit not ready
Reaction: OFF2 (NONE)
Acknowledge: IMMEDIATELY
Cause: After an internal power-on command, the infeed or drive does not signal ready.
- monitoring time is too short.
- DC link voltage is not present.
- associated infeed or drive of the signaling component is defective.
- supply voltage incorrectly set.
Remedy: - increase the monitoring time (p0857).
- ensure that there is a DC link voltage. Check the DC link busbar. Enable the infeed.
- replace the associated infeed or drive of the signaling component.
- check the line supply voltage setting (p0210).
See also: p0857 (Power unit monitoring time)
A07805 (N) Drive: Power unit overload I2t
Reaction: NONE
Acknowledge: NONE
Cause: Alarm threshold for I2t overload (p0294) of the power unit exceeded.
The response parameterized in p0290 becomes active.
See also: p0290 (Power unit overload response)
Remedy: - reduce the continuous load.
- adapt the load duty cycle.
- check the assignment of the motor and power unit rated currents.
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SINAMICS G120 Control Units CU230P-2 Parameter Manual (LH9), 01/2011
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