Hi every body,

In our power plant, there are two GE FRAME 9E gas turbine with MKV TMR.I have noticed the power supply data from DIAGC DATA display - TCQAG1B for core R are as follow:<pre>
P5v = 5.11 vdc
P15a = - 0.12 vdc ( JE - 29 = -0.02 )
N15a = 17.09 vdc ( 30 = 3.00 )
P15b = 9.45 vdc ( 31 = 1.55 )
N15b = -17.1 vdc ( 32 = -3.00 )
P125v= 1.98 vdc ( 33 = 0.04 )
N125v= 152.89 vdc ( 34 = 3.00 )

Also the power supply values of IOMA for same core are:
P5- voltage = 0.00v
P15- voltage = 29.2v
N15- voltage = 0.00v
P24- voltage = 14.2v
N24- voltage = -14.3v
DCOM- voltage = 1.3 v</pre>
While S&T are normal.
I did the following procedures :

1.Replacing TCPS of core R without result.

2.Replacing TCQA no result.

3.Replacing TCQC no result.

4.Replacing SDCC & SLCC no result.

5.I swapping SDCC & SLCC of core T with core R,so the problem had transferred to core T, and all above voltages were correct at core R, but status of both cores was A6. so I returned each core to its place.

6.Replacing EEPROMEs of SDCC (DS200GHDQF1CBG 01&2) WITHOUT RESULT.
The diagnostic alarm is:
IOMA power supply out of limit, P5, P24, P15, N24, N15, DCOM.

There is no 125 v dc battery ground, and the voltages are +65.44 v & -65.4 v at core PD.

Also no difficulties, intermittent with the operation of the unit > So pls any solution for this problem.

 

It would be helpful to know when this problem started. Such as after some card was replaced, or after some maintenance outage (say, when the Mark V was powered-down for some time and then power was re-applied and the alarm started at that time or shortly after that).

It's been said many times before on control.com: For proper operation/indication DIAGC requires that the DIAGC.DAT file be specific for every card and PROMset in the panel. Basically that means that every DIAGC.DAT must be customized for every panel, and that if any cards or PROMsets are ever replaced with newer versions that DIAGC.DAT must also be updated appropriately.

The sad, but true, fact is that DIAGC.DAT was almost NEVER customized during the initial commissioning, and is almost never updated when new PROMsets or updated card revisions are installed. So, many times the data reported by DIAGC.DAT can be misleading; in fact, I'll go on record as saying that many times it is misleading.

Many times the problem with DIAGC.DAT is never discovered until someone tries to use DIAGC.DAT for troubleshooting purposes. Or, until some curious soul with too much time on their hands starts looking at DIAGC.DAT out of curiosity and discovers mismatches and seemingly-odd data. And, as you report there is no apparent trouble with the operation of the Mark V, just inconsistent and odd data/values reported by DIAGC.

And most times, it's ultimately discovered that DIAGC.DAT was never customized nor maintained over the years.

It's telling that when you moved the SDCC/SLCC cards the problem followed those cards. But that's about the extent of my impression about this problem. Mostly because I don't trust DIAGC unless I know, personally, that DIAGC.DAT exactly matches the configuration of cards and PROMsets in the panel. And, there are only a couple of people in the world (both of whom work for GE) who can review the file and say it's correct or not. And getting to them is very difficult, nigh on impossible these days.

I believe the reason that the two processors you exchanged SDCC/SLCC cards between only went to I/O Status A6 is because you probably didn't change the Voter ID when you swapped the cards. Had you changed the Voter IDs and then re-started the processors, they probably would have gone to A7.

Depending on the version of Mark V and the version of cards and PROMsets in the panel, the 'IOMA Power Supply Out of Limits' might be a nuisance Diagnostic Alarm that can be solved with a PROM upgrade. But, that would involve working with GE to analyze the cards and PROMsets installed in the panel to determine if that would solve the problem.

I wish I had more information. I believe there are some test rings on the SDCC card which can be used to measure the voltages with a voltmeter. The test rings are labeled with silk-screened lettering on the card. If you wish to pursue this problem with GE or one of its packagers, you would do well to gather as much information, including the voltages measured at the test rings, and also provide all of the card revision information (from the card labels by actually looking at and recording that information!) and from the PROM labels (by actually looking at and recording the information from the PROM labels), as well as passing the results of a CARD_ID.EXE execution. Perhaps with that information they could help you or direct you to some resolution.

Unfortunately, there's just not enough documentation out there in the world for us to be able to provide any more information at this time.

Please write back to let us know if you are able to resolve this problem.