We had a faulty <T> core DCCA card with PN:531X301DCCAFG2. We got a new replacement card with PN:531X301DCCAGG2. DCCA card needs replacement since it lost the display on the LCCB card and would not boot up.

I installed the new 531X301DCCAGG2 card and when <T> core was powered up it stays on A4 status. I have checked the IO states when <T> core was in status A4. The IO card condition were as follows:

OBJ ID 1 TCQA A4
OBJ ID 4 **** A1
OBJ ID 8 LCCQ A4
OBJ ID 12 DCCQ 00
OBJ ID 13 IOMA A4
OBJ ID 15 **** A1

We borrowed another DCCA card from other plant with PNS200SDCCG4AFD. This card had 4 slots of EEPROM for GASQ & IOMA. The old card we had is having 6 slots of EEPROM for GASQ, IOMA & DSPA.

Is it possible to replace the card 521X301DCCAFG2 with DS200SDCCG4AFD?

We were starting our gas turbine and could not proceed with this issue.

 

benjovr,

I'm not quite sure I understand the post, nor do I agree with the reasoning for replacing the DCCA card.

>DCCA card needs replacement since it lost the display on the LCCB
>card and would not boot up.

I would suggest if the LCC display doesn't work, it's a problem with the LCC card or the cabling powering the DCC/LCC card. The LCC card is a daughter-board (a smaller card that's mounted on the "parent" card--the DCC in this case). Have you checked all the fuses on the TCPS card? Some are in very difficult positions to see unless the card is removed from the back of the core.

Also, the cable between the LCC, the DCC and the TCQA is notorious for not making good contact and intermittent operation. The 3PL cable is the one which DOES NOT have any pull tabs on it, making it difficult to remove when replacing cards, causing even more problems that the one originally being troubleshot.... Make sure the cable connections are all tight and firmly connected, and when disconnecting this cable anywhere along its length use great care not to disturb the delicate connectors.

Many times just a very firm press all along the length of the connector when inserted in the receptacle will restore connections between the cable and the connector.

>OBJ ID 1 TCQA A4
>OBJ ID 4 **** A1
>OBJ ID 8 LCCQ A4
>OBJ ID 12 DCCQ 00
>OBJ ID 13 IOMA A4
>OBJ ID 15 **** A1

I think OBJ ID 4 is the TCDA card (or the TCEA card--sorry I can't remember exactly which), which is connected to the core via the IONET cable that runs between the TCQA, the TCEA and the TCDA in the <QD1>
core. Neither the TCEA nor the TCDA card appear in the list, so it could be something's amiss with the IONET--but it could just be that the DCC is not communicating with the LCC.

>We borrowed another DCCA card from other plant with
>PNS200SDCCG4AFD. This card had 4 slots of EEPROM for GASQ
>& IOMA. The old card we had is having 6 slots of EEPROM for
>GASQ, IOMA & DSPA.
>
>Is it possible to replace the card 521X301DCCAFG2 with
>DS200SDCCG4AFD?

The Gn designation is the Group Number of the card. It's not generally possible to replace a G2 with a G4, but I don't have my secret decoder ring for all the possible permutations of card combinations possible and not possible for the Mark V. Sometimes, with certain PROMsets, different Group numbers can be substituted, but in this case, I think not.

Also, I'm not familiar with a DSPA PROMset.... I don't actually think it's a PROMset that is intended to be replaced when swapping cards; not all PROMsets were. Some were just socketed firmware PROMs that
weren't intended to be replaced.

Without knowing the entire PROMset designations it's not possible to say for sure. Unfortunately, GE is about the only place to get these kinds of questions answered--because they didn't document any of this stuff very well, and because, there were always exceptions to many "rules" too, and even they forget some of these exceptions.

You may try contacting one of the advertisers here on control.com, Gas Turbine Controls (www.gasturbinecontrols.com) to see if they can help you with this particular query and card request. However, personally I'm not convinced that there's a problem just yet. I would have to know if all the fuses on the TCPS were okay (and again, some of there are not easy to locate; perhaps if you have a spare TCPS card you just might try replacing the existing one--after you re-install the original DCCA card--to see if that's the problem).

Another common problem with older Mark V panels is that the ribbon cable pins and sockets were very susceptible to corrosion and this has caused a lot of problems. GE has recommended using a light coating of a conductive grease (such as is used on heat sinks of PC main microprocessors, commonly available from a PC parts supply outlet) to prevent corrosion.

And, it's a good idea to always unseat and re-seat all connectors in the Mark V panel a couple of times each once every year or two (with the power completely removed from the panel!) just to dislodge any corrosion which might build up. I also recommend using a new light coat of conductive grease every couple of years because it doesn't last forever. GE also was supplying small tubes of conductive grease in the boxes with spare cards for many years, so, if you purchased spare Mark V cards from GE in the past few years you can check those boxes to look for any conductive grease if you don't have any or can't purchase some quickly.

My first suggestion would be to replace the original DCCA card and PROMs back in the <T> core, make sure all the ribbon cables are good and tight and clear of any corrosion, inspect the <T> TCPS card (in Loc. 5 of the TCPS--all the way in the back--and to locate and check all of the fuses it's often easiest just to remove the card from the core to remove the fuses to check them with an ohmmeter), and if all the TCPS fuses are good, the re-apply power to the <T> core and observe what happens. I've also seen some very strange problems with the TCQC card cause strange Diagnostic Alarms and DCC/SDCC issues; just replacing the TCQC card can also be a possible solution when all else fails. (I'm not a big proponent of swapping cards, but sometimes it's necessary.)

To answer the primary question, I don't think a G4 DCCA can be used to replace a G2 DCCA, but since GE didn't document all the possible combinations and there were exceptions to every rule I can't say for sure.

Wish I could have been of more help! Please write back to let us know how you fare in resolving this issue.

 

I have checked the TCPS voltages and measured correct value of P5, P15, N15, P24 & N24. I replaced the DCCA card since it has an almost burnt capacitor C49 just near the 6PL socket.

I had removed the U9 IC from the old card and installed in the new DCCA card. Power up the core and changed the setting in the LCCB display. Rebooted again and it reached A7 status.

I got now all processor at A7 but another problem crop up. Sets of alarms from CD DTBA & DTBB could not reset. I replaced the TCDA but problem still exist. I replaced also the DTBA but did not solve the issue. I even replaced the DCCA card and still the alarm won't reset from directly linking the point in the DTBA terminal. I ruled out ground fault since I got balance voltage of +/-60VDC.

What would be the reason of this problem and how to resolve it.

Thanks CSA and appreciated your support on this issue.

 

> Sets of alarms from CD DTBA & DTBB could not reset.

Um, what kind of alarms--Process or Diagnostic?

What are the alarms (specifically)?

I believe the Mark V Maintenance Manual, GEH-6195, shows the IONET from <C> runs between the TCCA and the TCDA. The IONET termination resistors on the TCDA should be in the IN position.

What took place just before these "Sets of [undefined] alarms" we're annunciated? We're you downloading to and re-booting <C>?

Really, you haven't provided enough information to be of much help.

 

Hi,

Would you wish to get your faulty cards repaired with a warranty of 12 months. I can also forward your issue to my engineers and get your questions answered.

If you could share your e-mail id with me, i can send you our profile and repair services history.

Hope it could be of help to you.

Regards,
Briha

 

>> Sets of alarms from CD DTBA & DTBB could not reset.
>
>Um, what kind of alarms--Process or Diagnostic?
>
>What are the alarms (specifically)?

Kind of alarms is process as listed below.<pre>
22-JUN-2015 15:34:39.093 T1 1 Q 0085 CUSTOMER TRIP
22-JUN-2015 15:34:39.093 T1 1 Q 0086 CUSTOMER START INHIBIT
22-JUN-2015 15:34:39.093 T1 1 Q 0101 TURBINE AIR INLET DIFF PRESS SHUTDOWN
22-JUN-2015 15:34:39.093 T1 1 Q 0111 LUBE OIL TANK TEMPERATURE LOW
22-JUN-2015 15:34:39.093 T1 1 Q 0134 RATCHET TROUBLE
22-JUN-2015 15:34:39.093 T1 1 Q 0170 GAS FUEL PRESSURE LOW
22-JUN-2015 15:34:39.093 T1 1 Q 0196 GENERATOR DIFFERENTIAL TRIP
22-JUN-2015 15:34:39.093 T1 1 Q 0229 MCC UNDERVOLTAGE
22-JUN-2015 15:34:39.093 T1 1 Q 0283 BATTERY 125 V DC GROUND
22-JUN-2015 15:34:39.093 T1 1 Q 0377 ESD VALVE FAILURE TO CLOSE
22-JUN-2015 15:34:39.093 T1 1 Q 0379 INST. AIR PRESSURE LOW
22-JUN-2015 15:34:39.093 T1 1 Q 0479 FIRE
22-JUN-2015 15:34:39.218 T1 1 Q 0109 LUBE OIL LEVEL HIGH
22-JUN-2015 15:34:39.218 T1 1 Q 0110 LUBE OIL LEVEL LOW
22-JUN-2015 15:34:39.218 T1 1 Q 0150 TURBINE COMPARTMENT TEMPERATURE HIGH
22-JUN-2015 15:34:39.218 T1 1 Q 0230 AUXILIARY MOTOR OVERLOAD
22-JUN-2015 15:34:39.218 T1 1 Q 0528 GAS FUEL NOZZLE PURGE VALVE NOT CLOSED
22-JUN-2015 15:34:39.218 T1 1 Q 0533 GAS NOZZLE FUEL PURGE VALV DID NOT OPEN
22-JUN-2015 15:34:39.218 T1 1 Q 0536 TURBINE COMPARTMENT TEMP HIGH STOP
22-JUN-2015 15:34:39.218 T1 1 Q 0539 LUBE OIL VENT TEMPERATURE HIGH ALARM
22-JUN-2015 15:34:39.218 T1 1 Q 0540 MOTOR CONTROL CENTER 110 V UNDERVOLTAGE
22-JUN-2015 15:34:39.218 T1 1 Q 0541 OIL DEMISTER 88QV1 TROUBLE
22-JUN-2015 15:34:39.218 T1 1 Q 0545 COMPRESSOR BLEED VALVE POS TROUBLE TRIP
22-JUN-2015 15:34:39.218 T1 1 Q 0547 HIGH VIBR STOP COOLING TOWER FAN #1
22-JUN-2015 15:34:39.218 T1 1 Q 0548 HIGH VIBR STOP COOLING TOWER FAN #2
22-JUN-2015 15:34:39.218 T1 1 Q 0549 HIGH VIBR STOP COOLING TOWER FAN #3
22-JUN-2015 15:34:39.218 T1 1 Q 0550 BENTLEY N. VIBRATION DANGER LEVEL
22-JUN-2015 15:34:39.218 T1 1 Q 0556 GENERATOR AIR FILTER HIGH DIFF PRESSURE
22-JUN-2015 15:34:39.218 T1 1 Q 0557 STOP FROM GENERATOR
22-JUN-2015 15:34:39.343 T1 1 Q 0075 OVERSPEED BOLT TRIP - HP
22-JUN-2015 15:34:39.343 T1 1 Q 0132 STARTING MOTOR THERMAL STATE HIGH
22-JUN-2015 15:34:39.343 T1 1 Q 0136 RATCHET MOTOR OVERLOAD
22-JUN-2015 15:34:39.343 T1 1 Q 0476 FIRE PROTECTION SYSTEM TROUBLE
22-JUN-2015 15:34:39.343 T1 1 Q 0564 HAZARDOUS GAS 60% LEL LEVEL 2 OUT 4 TRIP
22-JUN-2015 15:34:39.343 T1 1 Q 0568 GAS HEATER ALARM
22-JUN-2015 15:34:39.343 T1 1 Q 0570 FIRE SHUTTER GASTURBINE COMPT. CLOSED
22-JUN-2015 15:34:39.343 T1 1 Q 0571 FIRE SHUTTERS IN GEN. COMPT. CLOSED
22-JUN-2015 15:34:41.093 T1 1 Q 0534 AIR FILTER HIGH DIFF PRESSURE ALARM
22-JUN-2015 15:34:41.093 T1 1 Q 0538 OVERLOAD HEATER 23HA AUX COMPARTMENT
22-JUN-2015 15:34:44.031 T1 1 Q 0567 FIRE DETECTION TEMP/UV HIGH ALARM
22-JUN-2015 15:34:49.093 T1 1 Q 0233 BATTERY CHARGER AC UNDERVOLTAGE
22-JUN-2015 15:34:54.093 T1 1 Q 0105 MAIN LUBE OIL FILTER DIFF PRESSURE HIGH
22-JUN-2015 15:34:54.093 T1 1 Q 0267 TRIP OIL FILTER DIFF PRESSURE HIGH
22-JUN-2015 15:36:18.093 T1 1 Q 0000 DIAGNOSTIC ALARM <C><Q></pre>
The berg jumpers J2 & J3 in TCDA are in the IN position.

The unit was down for maintenance and we are in the process of normalizing the Mark V panel. All cores went to A7 status after replacement of T core DCCA card. These alarms appeared and we are trying to reset it but to no avail. We tried to link the input in the DTBA card and there was no response. We tried replacing the DTBA and TCDA card but did not correct the problem.

The JQ ribbon cable connecting TCDA & DTBA was checked pin to pin and it had good continuity.

Diagnostic alarm also appeared as below.<pre>
22-JUN-2015 15:51:16.000 T1 1 T 0962 TCD1 BATREF signal failure (plug JQ)
22-JUN-2015 15:51:16.000 T1 1 T 1328 TCQA LVDT regulator #1 feedback trouble
22-JUN-2015 15:51:16.000 T1 1 T 1329 TCQA LVDT regulator #2 feedback trouble
22-JUN-2015 15:51:16.000 T1 1 T 1332 TCQA LVDT regulator #5 feedback trouble</pre>

 

Hi Briha,

Here is my e-mail address [email protected]

Regards

 

The 'tell-tale' alarm is the BATREF alarm. This means the <CD> core is not getting the (nominal) 125 VDC for the contact input interrogation/wetting voltage, or, the power for the TCDA card from the TCPS in <C> is missing. But the <C> TCDA is unable to reference the contact inputs to the battery supply voltage. Which is why all of the Process Alarms are coming from <C>. And most of them are likely from contacts that open to alarm, but are physically closed, but the TCDA can't determine they're closed because of the loss of the battery reference voltage.

Again, this is usually because of the lack of power from the TCPS (or the lack of a ground reference from the TCPS) in <C>. But sometimes it's the result of one or both of the fuses supplying the <CD> core have blown (opened). I can't recall the cable number (I think it's J12) that takes the power to the DTBA from the fuses in the <PD>, but you can unplug the cable from the DTBA and then measure each pin to ground to see if one or both is missing, then check the fuses for the <CD> contact inputs in the <PD> core.

There might also be a blown fuse on the <C> TCPS, or a problem with the ground wire connected to the TCPS in <C>.

But for some reason the TCDA in <CD> isn't getting all the voltages/ground references it needs to properly recognize closed contact inputs.

Hope this helps!

 

I have checked the voltage levels at test pins and all are in specified voltages settings as indicated in GEH-5980.

I replaced <C> TCPS and rebooted. Your analysis of the issue are very correct. The remaining alarm now were the real ones and the TCDA are totally functional.

Thank you and much appreciated your great help and assistance in our issue.

Best Regards,
Benjamin

 

Benjamin,

Thanks for the feedback!

And, remember: Contrary to popular belief, Diagnostic Alarms can (and do) really have meaning and can be useful for troubleshooting.