09.02  Fault and Alarm Messages 
Siemens AG    6SE7087-6AK85-1AA0 
7-3 
Rectifier/Regenerating Unit    Operating Instructions 
Fault 
No. 
Fault description 
Fault 
value 
Meaning  Possible causes 
Countermeasures 
F022 I
2
t Overload 
I
2
t monitor of the power section has 
responded 
 
The monitor responds when 100 % of the 
calculated I
2
t value of the power section is 
reached. 
-  -  - Drive operated too long under 
overload conditions 
- Check to see whether the rated 
current of the R/G unit is 
adequate for the specific 
application 
- See also P785 
F023 LT-Temp. 
Temperature of the power section too high 
 
A check is made to see whether the heat 
sink temperature measured using 
thermistor(s) is > 95 °C (or 123,9°C) 
1 
Heat sink temperature > 95 °C 
 
or with water-cooled units: 
heat sink temperature > 123,9 °C 
- Heat sink (air inlets and outlets) 
contaminated 
- Heat sink temperature sensor not 
connected to X31, X32 on A1681 
and/or A1682 module (“slave 
unit”) 
- Fan has no voltage 
- Fan faulted 
- Fan running in the wrong 
direction 
- Fan fuse (F3, F4) defective 
NOTE: 
- Measure inlet air ambient 
temperature. If ϑ > 40 ºC, note 
reduction curves. See Section 
14.1. 
With water-cooled units: 
- Water inlet temperature too high, 
cooling circuit interrupted or 
cooling water pump faulty 
Temperature of the power section too low  2 
Heat sink temperature ≤ -45 °C 
- Heat sink temperature sensor not 
connected to X30 module on 
A1681 and/or A1682 
F029 Measure Flt 
Fault in line voltage measurement 
 
An offset > 5% has been detected when 
attempting to compensate for the offset of 
the line voltage measurement 
1 
 
 
2 
 
 
3 
 
 
4 
Channel V-U faulted 
(regenerative feedback 
direction) 
Channel V-W faulted 
(regenerative feedback 
direction) 
Channel W-U faulted 
(regenerative feedback 
direction) 
Channel W-U faulted 
(infeed direction) 
- Fault in the voltage path on the 
power interface module (A1681 
and/or A1682 and/or A1685) or 
on the electronic module (CUR) 
F030  DC Bus Short 
DC link short-circuit 
 
The monitor responds if the following 
conditions obtain for longer than 0.5 sec: 
-  The current limit of the 
rectifier/regenerating unit is reached 
(this condition does not apply during 
circuit identification or during DC link 
forming) 
-  The rectifier or regenerative current is 
greater than 10% of the rated DC 
current (P075) 
-  The DC link voltage is less than 5% of 
1.35*P071 
-  -  - Short-circuit in the DC link 
F031  Fuse Blown 
Fuse blown in a thyristor branch of the 
rectifier/regenerating unit or of a parallel 
power section. 
-  -  - Thyristor branch fuse faulted 
F032  Phase Sequ.? 
Wrong phase sequence 
 
A check is make to see whether the phase 
sequence of the rectifier bridge is the 
same as that of the regenerative bridge. 
-  -  - Phase sequence of the rectifier 
bridge different from that of the 
regenerative bridge 
AoteWell Automation Sales Team
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