09.02  Fault and Alarm Messages 
Siemens AG    6SE7087-6AK85-1AA0 
7-5 
Rectifier/Regenerating Unit    Operating Instructions 
Fault 
No. 
Fault description 
Fault 
value 
Meaning  Possible causes 
Countermeasures 
F048 RAM Fault 
RAM defective 
 
Software-based checking of the 
functionality of the RAM chips on the CUR 
module 
-  -  - RAM defective (replace the CUR 
module) 
F049 Watchdog! 
Watchdog timer has triggered a Reset 
 
An internal hardware counter in the 
microprocessor checks to see whether the 
program for calculating the firing pulses is 
executed at least about every 400 ms (on 
average, it is executed every 2.7 to 3.3 
ms). If this is not the case, the counter 
triggers a Reset. F047 then appears. 
-  -  - CUR module defective 
- Excessive interference (e.g. by 
contactors without RC elements, 
unshielded cables, faulty 
shielding connections) 
F060 No MLFB 
P070=0 
-  -  - After acknowledging in 
BOOTSTRAP, enter a suitable 
parameter value for the unit with  
P070 MLFB (6SEE70..) (only 
possible with the corresponding 
access stages of the two access 
parameters; see Section 4.3.9.2). 
F061 WrongPar Set 
Parameter wrong or not yet set 
3  P141 (Rectifier Induct.), P143 
(Inverter Induct.) or P144 (C of DC 
link) are = 0.00 
- Carry out circuit identification 
(P052 = 21) 
 
 
 
Note about fault value 4, 5: 
The U
d
 reduction is then considered to be 
"selected" if while the basic setting 
P571.i001 ≠ 0 active
 or while the standby 
setting P571.i002 ≠ 0 active
, or if P323=1. 
4  P318 is too large (with U
d
 reduction 
selected) or P776 is set too small 
to facilitate constant regenerative 
operation with continuous
 DC link 
current for the current ratio of 
rectifier/regenerating supply 
voltage. 
As the inverter step limit P776 with 
respect to the commutation 
duration (depending on u
K
 value of 
the network) has an upper limit, 
P318 has to be set lower, or U
d
 
reduction has to be activated via 
P571if it is not currently active. 
The following must apply: 
cosP776100%
U
U
P318
rect. Supply,
reg. Supply,
≤
or. 
if operating without U
d
 reduction: 
cosP776100%
U
U
100%
rect. Supply,
reg. Supply,
≤
 
  5  P318 is too large (with U
d
 reduction 
selected) to facilitate constant 
regenerative operation with 
pulsating
 DC link current for the 
current ratio of 
rectifier/regenerating supply 
voltage. 
P318 has to be set lower, or U
d
 
reduction has to be activated via 
P571if it is not currently active. 
The following must apply: 
%62,87
U
U
P318
rectifier Supply,
ngregenerati supply,
≤  
or 
if operating without U
d
 reduction: 
%62,78
U
U
100%
rectifier Supply,
ngregenerati Supply,
≤
 
 
 
Autotransformer connected incorrectly  6 
1,1
1
 < 
U
U
rectifier Supply,
ngregenerati Supply,
 
 
 
 7 
P076 ≠ 0xx UND Unit is an E unit 
(P070 ≥ 101) 
- Set P076 correctly 
 
  8  P076 = 10x, 20x or 21x 
(i.e. more parallel recovery power 
sections are parameterized than 
parallel feed power sections) 
- Set P076 correctly 
F065 SST1 Telegr. 
USS telegram to SST1 failed 
 
Active from the first reception of a valid 
protocol in all operating states 
 
Following receipt of a valid telegram, no 
further telegrams were received for longer 
than the time set with parameter 
P687.i001 
- -  - Cable break 
- Fault in the USS master 
AoteWell Automation Sales Team
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