dear all,

below is diagnostic alarm report

24-JUL-2009 09:39:39.000 T1 0 C 1946 Voter mismatch, <R> L74CR.

in prevote data display, value for vote 0, <R> 1, <S> 0, <T> 0.
This signal came from DGP - self test failure and will initiate a shutdown.

We already check the DGP. the status is OK and there is no fault recorded. In our opinion, if this problem came from the input why only <R> detect it. To solve this problem we already change the TCDA, TCEA and DCC card. But the alarm still persist.

Any information will be very useful, thank you.

 

The alarm by its name voter mismatch is a direct outcome of the misalignment amongst the cores reading the individual values. The values upon their sequential exchange would be read by each processor and depending on what the individual processor's reads a resultant output would be generated. Mind well, mismatches are also being indicated and logged to inform and to eliminate any spurious detection and hence are out-voted else could have resulted in a trip (for simpelex mode. As for L74CR, please give the details of your machine, the mode of operation etc

 

Our machine is GE MS6001B, use Speedtronic MK V TMR with <I>. This machine operate during the peak load, so usually start and stop every day.

For more information, as shown in appendix D, GEH-6195D (signal flow diagram) I try to trace the signal flow. Signal L74CR is an output from Digital Generator Protection (DGP54AABA), connected to DTBA terminal board (CI043, screw #85). From DTBA to TCDA (QD1).
My question is, from TCDA, the signal "feed" directly to DCC or via TCEA, because there is a cable (JX) from TCDA to TCEA. A black and white cable which I thought an IONET cable.

Thank you, still hope for more information

Regards,
Hartanto

 

QD1 is the digital I/O for the three cores and i.e. IONET connection between QD1 and individual cores. I would not be able to furnish more information than this

Hope you get some clue

 

i use the viewq command to check the value of L74CR in each core, this is the result :
## Unit Pointname Scale
-- ---- ------------ -----
1 T1 L74CR LOGIC

07-AUG 07:00:16.656 0
07-AUG 07:00:16.656 0
07-AUG 07:00:16.656 0
07-AUG 07:00:16.687 0
07-AUG 07:00:16.687 0
07-AUG 07:00:16.687 0
07-AUG 07:00:16.718 0
07-AUG 07:00:16.718 0
07-AUG 07:00:16.718 0
07-AUG 07:00:16.750 0
07-AUG 07:00:16.750 0
07-AUG 07:00:16.750 0

I'm stuck in here, why in prevote data display value for L74CR in core R is 1, when the result from viewq command are 0.

any suggestion will be helpful.

thank you