Commutation Failure - Siemens SINAMICS DCM List Manual

For a control module with option Z01... Z15, the following applies:
The fault threshold for the differential pressure was fallen below.
Alarm value 2: differential pressure at LT1 fallen below
Alarm value 3: differential pressure at LT2 fallen below
r50047[1]: Fan monitoring mode (p51832)
Remedy: - Check wiring of "Fan OK" message via input terminal 122/123.
- Check the setting of the mode for fan monitoring (p51832).
- Check the fan and replace if necessary.
See also: p51832 (Fan monitoring configuration), p51835 (Delay times for device fan monitoring)
Reaction upon N: NONE
Acknowl. upon N: NONE
Reaction upon A: NONE
Acknowl. upon A: NONE
F60300

Commutation failure

Message value: %1
Message class: General drive fault (19)
Drive object: DC_CTRL
Reaction: OFF2
Acknowledge: IMMEDIATELY
Cause: Commutation failure or overcurrent has occurred or a test command was entered via p51583.
Possible causes of the commutation failure:
- Line voltage dip during regenerative operation.
- Armature current control loop not optimized.
Fault value (r0949, interpret decimal):
1:
Commutation was not successful because the thyristor being turned off did not accept the blocking voltage (only for
p50166 = 1).
r50047[0]: Decision criterion (= 1)
r50047[1]: Thyristor state (= r53146)
r50047[2]: Fired thyristor pairs
Bit 0 = 1: Thyristor 1 in MI was fired
...
Bit 5 = 1: Thyristor 6 in MI was fired
Bit 8 = 1: Thyristor 1 in MII was fired
...
Bit 13 = 1: Thyristor 6 in MII was fired
r50047[3]: Actual armature firing angle [in degrees]
r50047[4]: Actual EMF in [in %]
2:
The current did not flow through the correct thyristor or the current cusp made a kink upwards.
r50047[0]: Decision criterion (= 2)
r50047[1]: Subcriterion
For subcriterion = 1 , the following applies:
The current did not flow through the correct thyristors.
r50047[2]: Actual Ia sample value [in A]
r50047[3]: Actual Ia sample value CT 1 [in A]
r50047[4]: Actual Ia sample value CT 2 [in A]
r50047[5]: Actual Ia sample value + 20% of In [in A]
r50047[6]: Number of Ia sample values since the last firing pulse
SINAMICS DCM
List Manual (LH8), 02/2015, 6RX1800-0ED76
4 Faults and alarms
4.2 List of faults and alarms
1175