The frame 6b gas turbine got a lighting discharge. The core <C> tcca card (location 2) and the slcc card (location 1b) got damage. Both cards were replaced using the same eeproms that were originally installed. But now the digital I/O of card dtba & dtbb are not working. Even do Core <C> is showing "A7", an at its io status shows everyone at "A7". The dtbc & dtbd cards are working ok. Which other card or element (eeproms, etc) should be check.

 

If <C> is showing I/O Status A7 then it's not likely a EEPROM problem on either card.

<b>WHAT DIAGNOSTIC ALARMS ARE BEING ANNUNCIATED?</b> Is one of them something like "BATREF LOST"?

Have you checked for the presence of 125 VDC at the DTBA and DTBB cards?

That power should come on to the DTBA via the J12 connector, and it should jumper from the DTBA to the DTBB card (I don't recall what the jumper is called; but's an unshielded twisted pair cable--as is the cable that connects to J12 on the DTBA).

The other end of the J12 cable that's connected to the DTBA card should be coming from a J12x connector in the <PD> core. There should be three J12X receptacles on the TCPD card in <PD>: J12A, J12B, J12C. Usually, J12C is the one that supplies the DTBA and DTBB of the <CD> core, but that might not be the same for every turbine.

J12C is powered through FU25 and FU26 on the TCPD card in <PD> core. Have you checked the fuses?

The DTBA and DTBB are connected to the TCDA card in Loc. 1 of the <CD> core. You may need to replace the TCDA card, swapping PROMs from the old card to the new card as you've done before.

Again, if <C> is at I/O Status A7, then it's not likely the PROMs.

But stranger things have happened.

Please write back to let us know how you solved the problem!

 

Check your relay boards in <CD>. Although TCDA is sending signals the relays are not operating. I have experienced this on lightning problems. The lightning hit the switch yard and also destroyed the terminal boards for generator breaker operation in <P> core. If a similar failure has occurred you will visually see the damage on the relay boards.

 

Yes, we got the 125 Vdc at DTBA and DTBB cards. That's the issue, we make a jumper an we dont see the status to change. As an example, we have at the io.asg file an assignment at DTBA 19,20 terminals for the signal L43HRJOG CIM (ratchet jog button), but when you do a jumper between this two terminals it is suppose the signal status should change, but it is not happening. We have verify the existence of the 125 Vdc.
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All supply coming from <PD> core have being verify, all it fuses (all related leds are on-green). That's the strange thing.

TCDA card was replaced an old eproms were reinstalled. That's one of the things (the eprom)that is the same since the event (lighting), but the thing is that at io status check at core <C> it says TCDA1 "A7" so it means it is okay.

From the way the control for the i/o digital and solenoid goes from core <C> to core <CD>, at this moment we are suspicious about DCC card (core <C> location 1B), its 4 eproms, or TCDA card (core <CD> location 1)and its eprom. What you think about that my friend???

In relation to the diagnostic alarms, the <I> got 2 pages of this diagnostics alarms. To be honest with you, at this site there are three gas turbines, an all of them having running with a great amount of diagnostics alarms (one of them, the newest one, got 8 pages of diagnostics alarms). I don't mean this is okay, but at least, i don't think they are exactly the ones producing this problem with the dtba & dtbb cards.

 

The TCRA card of the <CD> core was check, but remember this cards control your output to the dtbc and dtbd card, an they are working ok. Between the tcda card and your dtba & dtbb card the only connection are the ribbon cable. an both of them have being check.

 

Can you force relay outputs of the <CD> core to "1" and "0"?

If so, one would believe the IONET is working properly.

There are LED "bargraphs" on the TCDA cards in <CD> and <QD1>. When there are no Diagnostic Alarms then they should all blink in the same sequence at the same time.

The problem is--with <b>SO</b> many Diagnostic Alarms you can't refer to the TCDA cards in <QD1> to see if the one in <CD> is working properly!

You seem to be headed in the right direction. At this point, it would seem that exchanging DCC cards is the next step.

Please keep us informed of the troubleshooting progress and problem resolution.