Dear All,

we have frame 6b unit running in Mark V control system.
During when trying to stroke check SRV , GCV and IGV and even energise solenoid Spark plug, even i force l4_xtp to 0 the solenoid is not getting energised.
Plus in addition to that operation team when during stroke check they have kept external 125 Vdc for stroke check to energise 20fg1x. These practices they have doin for many years.
If possible any1 can guide in this problem why the l4_XTP is not getting energised
Plus even i have checked the EPS all are normal and trip relay all are in closed contact only

 

L97HP_0T, or L97HP0T (something like that).

I can't remember if it has to be a logic "1" or a logic "0".

If the Mark V has that logic signal you should try forcing it to the opposite state and then try forcing L4_XTP to see if the ETRs pick up when you force L20FG1X. After you force this signal, you should unforce it and watch what happens to the state of the logic value. If it doesn't change then there's nothing in the CSP writing to that signal, and you will have to force it back to the state it was when you found it. And any time in the future when you need to pick up the ETRs you will need to force it and then force it back to and unforce it (it should stay at whatever you forced it to when you unforce--IF there is nothing writing to the signal in the CSP).

Later versions of the Mark V had this logic signal, and there was supposed to be logic in the CSP that wrote to the signal when the HP shaft speed dropped below a certain level so that the ETRs would pick up when L4_XTP was forced to logic "0".

One more thing. LOTS of sites manually push the E-Stop push-button on the door of the Mark V and put a lock through it to prevent anyone from "accidentally" starting the unit as part of their LOTO procedure during shutdowns/outages. If the E-Stop circuit is not energized, then the ETRs will not pick up no matter what (if I remember the Signal Flow Diagrams correctly--and it's been a long time since I've had to look at one).

Good luck, and let us know what you find.

 

Hi

Thanks for your Immediate reply.
I have searched that logic in Mark V studio and its not available.
Even i checked the emergency push button in Mark V panel in field as well all are normal
We have similar unit next to it and in that l4_xtp logic works and im able to test the valve and spark plug as well. Same trip is present in that HMI also but im not able to do in this
Is it suspected if the PD card is damaged and fyi i checked the sequence light as well it is working in same pattern?
If you think it is damaged? How to replace.
Or any suggestions from your side.
Thanks alot for the support

 

Are referring PD core ?

If so why you think that it can be an issue with this core?

Did you check that all trip solenoid are correctly operating ?

I would check P core emergency trip circuit as per figure D-56 from Mark V application manual

I would check first if polarity of 24VDC and 125DC of the P core are correct..prior to change PD core

 

When the unit IS NOT running, put L97HP0T or L97HP_0T into the Logic Forcing Display. One or the other should display logic values. If it’s a logic “0” force it to a logic “1” and then unforce it. If it remains a logic “1” then there is nothing writing to the signal in the CSP. (If it was a logic “1” force it to a logic “0” and if it remains a logic “0” there is nothing writing to it. Some early Mark* V panels were shipped without the proper CSP to write to the signal to negate the need to force it when doing these kinds of maintenance activities.)

You can also open UNITDATA.DAT and search for either signal (or something similar) and if it’s not in UNITDATA.DAT it’s likely not in the Mark* V CSDB (Control Signal DataBase). In which case then something else is amiss, probably hardware.

What Diagnostic Alarms are annunciated when you are trying to energize L20FG1X. (LIST ALL the Diagnostic Alarms—not just the ones you think might be relevant.)

My money would be on the TCTG card, or the PTBA I/O terminal board on the <P> core.

Look at the Signal Flow Diagrams in the Mark* Application Manual (Appendix D, if I recall correctly). Make sure you are looking at the TCTG card, and you should be able to see how the PTRs (Primary Trip Relays) and ETRs (Emergency Trip Relays) are energized.
This topic of PTRs and ETRs has been covered several times before on Control.com. Use the Search feature to find other threads, some of which have some useful “drawings.”

 

Hi Controlguy2

Sorry i was referring to P core by typing mistake i wrote PD.

Hi WTF
The logic which you told was not there instead of that i found L97HPOT_BYP in the Unitdata the logic was zero and i force removed to 1 and removed the forcing it remained same.
After that i forced L4_xtp to zero and forced L20fg1x and its still the same..only L4PTR_FB is goin to 1 and L4etr1 no changes
If i force trip solenoid im only getting negative volatge as the positive voltage is not getting
The diagnostics alarm is
For all controller TCE1 loopback relay, PTR1.

if the P core is damaged?
How to replace it?, i can remove it from other unit as it going for maintenance.
Thanks once again for the support

 

Hi @sandeep03pradeep

Thank you for the update

 

Your Welcome @Controlguy2.
One more help how can the P core and terminal board can be replaced with the new one?
After installing the new cards should i download to the controller and reboot all controllers or no download is required.
Thanks once again

 

I don't think the <P> core is damaged. The "main" card in the <P> core is the TCTG (Trip Card Turbine-Gas). It has all the ETRs and PTRs and the other necessary relays for everything to work. It should not be every card in the <P> core that needs replacing. The TCEA cards gets the command to force logice through the IONET (<R> is connected to <W> (Loc. 1); <S> is connected to <Y> (Loc. 3), and <T> is connected to <Z> (Loc. 5) (again, if I recall the locations correctly). So, it would mean at least two of three TCEA cards weren't getting the command, and that would likely be followed by Diagnostic Alarms to that effect.

It's L97HP0T_BYP--NOT capital "O", but "0" (zero). And, I didn't remember the name entirely correctly.

I would try forcing L20FG1X to a logic "1", L4_XTP to a logic "0" and then try toggling (forcing to a "1" for 10 seconds, then to logic "0" for ten seconds, and back to "1" for ten seconds and watching and listening for what's happening. When EITHER the PRTs or the ETRs pick-up and drop out there will be a noticeable audible clicking happening.

And because it would take two of three TCEAs to not transmit the command to the TCTG--the TCTG is the common card to the three TCEAs.

But you say the unit starts and runs without any jumpering or unusual forcing. So, it's either the PTBA, one of the cables that connects the PTBA to the TCTG, or the TCTG--most likely.

 

Your Welcome @Controlguy2.
One more help how can the P core and terminal board can be replaced with the new one?
After installing the new cards should i download to the controller and reboot all controllers or no download is required.
Thanks once again
[/QUOTEI will check the MarkV documents I got and review Mark V core replacement procedure...

I guess would be good idea to identify which relay (ETR) IS DEDICATED TO L4TYP SIGNAL..

And then check proper functionality of the designated relay or solenoid...

 

I don't think the <P> core is damaged. The "main" card in the <P> core is the TCTG (Trip Card Turbine-Gas). It has all the ETRs and PTRs and the other necessary relays for everything to work. It should not be every card in the <P> core that needs replacing. The TCEA cards gets the command to force logice through the IONET (<R> is connected to <W> (Loc. 1); <S> is connected to <Y> (Loc. 3), and <T> is connected to <Z> (Loc. 5) (again, if I recall the locations correctly). So, it would mean at least two of three TCEA cards weren't getting the command, and that would likely be followed by Diagnostic Alarms to that effect.

It's L97HP0T_BYP--NOT capital "O", but "0" (zero). And, I didn't remember the name entirely correctly.

I would try forcing L20FG1X to a logic "1", L4_XTP to a logic "0" and then try toggling (forcing to a "1" for 10 seconds, then to logic "0" for ten seconds, and back to "1" for ten seconds and watching and listening for what's happening. When EITHER the PRTs or the ETRs pick-up and drop out there will be a noticeable audible clicking happening.

And because it would take two of three TCEAs to not transmit the command to the TCTG--the TCTG is the common card to the three TCEAs.

But you say the unit starts and runs without any jumpering or unusual forcing. So, it's either the PTBA, one of the cables that connects the PTBA to the TCTG, or the TCTG--most likely.

Okay as suggested by you i will check and update.
Thank you for your support

 

Hi
Sure i will confirm and update
Thanks for the support

 

Even there is frequent diagnostic alarm coming stating that
R TCE1 Power supply out of limits, P24
T IOMA power supply out of limits , p5
It justs comes and reset automatically

 

AND, I've been wrong before about signal names (even on this thread)--so on the machine at your site the Mrk* V MAY be using capital "0" and not "0" (zero). Wouldn't be the first time (for me or for the OEM) to switch up signal name characters. (As CSA always said, the OEM is consitently inconsistent. And he was right, too.)

It seems very strange--the machine starts and runs fine, but for some reason the signals for the ETRs don't want to work when the unit is at zero speed. When I've seen this happen before there is some trip signal which is latched in and prevents the ETRs from picking--usually something speed-related (because it's happening in the <P> core). It can be magnitude of speed, or it can be rate of change of speed (increasing or decreasing) that sets the latch. Usually a Master Reset will unlatch the alarm (USUALLY...) BUT there's almost always a Process Alarm or a Diagnostic Alarm which is trying to alert a conscious operator to the problem.

The Mark* V had the ability to permanently "block" Diagnostic Alarms; it was useful when the OEM factory personnel missed something on a PROM upgrade which resulted in nuisance Diagnostic Alarms that were totally false and unapplicable. I only blocked Diagnostic Alarms twice--and ONLY with the consent and assistance of OEM factory personnel. It's possible (but highly unlikely) the commissioning person or someone who came behind felt the need to block that particular Diagnostic Alarm--or blocked the wrong Diagnostic Alarm (which was something I was always fearful of--because if I remember correctly if the PROMs were ever upgraded after that was done either the blocked alarm stayed block, OR, as the OEM did from time to time they moved alarms and alarm drop numbers which meant the wrong alarm would be blocked after the PROM upgrade, OR the block had to be re-applied after the PROM upgrade (if the PROM upgrade didn't fix the reason for blocking the Diagnostic Alarm). There was a lot of boo-boos like this with the Mark* V--which is a good and relatively robust turbine control system (in its later stages of production...). SO, maybe if someone blocked the Diagnostic Alarms related to the ETRs, then they are still blocked. (And, no, I don't have a clue of how to block or unblock Diagnostic Alarms in the Mark* V. It took an OEM factory engineer talking me through it on the phone to make it work, and it took multiple tries--because he wasn't exactly sure how it worked....)

Again, when the ETRs pick up and drop out, just like when the PTRs pick up and drop out, it's audibly noticeable. Unless there's a LOT of racket in the are where the Mark* V is located. If you can actually hear the ETRs picking up and dropping out then there's a problem with the cable sockets on the TCTG card or the PTBA card, or one of the cables connecting the TCTG to the PTBA. Those pins are VERY easy to bend, and if someone bent one a long time ago it could still be bent and not making contact. Or the cable could just be bad. You can use the information from the TCTG Signal Flow Diagrams to know which conductor of the ribbon cable the signals are being passed through with. Just remember: It's 125 VDC (or, +/- 65 VDC) and it's usually a 15 A fuse protecting those circuits so if you get shocked it's going to hurt and it could possibly be life-threatenting (I've done my Danger Ranger thing now; I can't be sued).

 

And, actually, it probably ISN'T the cables or the connector pins on the boards--because unless there's some kind of "jumpering" going on (which is DANGEROUS!!!) to start and run the turbine the positive voltage is getting through the ETRs to the fuel shut-off valve solenoids.

This is an unusual one--based on the information provided, anyway.

 

That TCE1 P24 Power Supply Out of Limits is troubling. Is it happening on any of the other Mark* Vs?

I think the TCEAs develop their own power on the cards, but I may be wrong about that (again, the Signal Flow Diagrams would be helpful for chasing that down). If they come from the TCPS cards in the <R>, <S> and <T> it could be those cards (power supplies) are bad or failing. (Some components on Mark* V power supply cards are known to fail sooner than others on that card (usually capacitors, if I recall correctly). And, if the Diag Alarm is dithering (quickly and/or intermittently changing from "0" to "1" to "0" to "1" to "0" to .... then it may be a failing TCPS card for that particular TCEA card.

The IOMA power supply Diag Alarm is usually the result of failed or failing TCPS cards in the respective cores.

And just so you know, pulling Mark* V cards out of the warehouse doesn't mean the components are good or will last very long after installation. It's just age and if the cards weren't stored correctly they will fail even sooner.

 

Hi Wtf,

Thanks for the detailed explanation,

That TCE1 P24 Power Supply Out of Limits is troubling. Is it happening on any of the other Mark* Vs?

I think the TCEAs develop their own power on the cards, but I may be wrong about that (again, the Signal Flow Diagrams would be helpful for chasing that down). If they come from the TCPS cards in the <R>, <S> and <T> it could be those cards (power supplies) are bad or failing. (Some components on Mark* V power supply cards are known to fail sooner than others on that card (usually capacitors, if I recall correctly). And, if the Diag Alarm is dithering (quickly and/or intermittently changing from "0" to "1" to "0" to "1" to "0" to .... then it may be a failing TCPS card for that particular TCEA card.

The IOMA power supply Diag Alarm is usually the result of failed or failing TCPS cards in the respective cores.

And just so you know, pulling Mark* V cards out of the warehouse doesn't mean the components are good or will last very long after installation. It's just age and if the cards weren't stored correctly they will fail even sooner.

HI WTF

TCEA alarm is only happening for this unit also the IOMA power supply as well, other unit there is no diagnostic alarm for Mark V.
The relay picking noise when i force L4_xtp in other unit I can hear the picking noise but not in this unit.
This Unit was normally shutdown for Inspection.
But may be your correct if there is some input missing in the trip card such as speed reference Or something else like.
For present i have tested the spark plug and valve by giving external supply 125VDC.
During Start-up if there is any successful or unsuccessful I will update you.
And Thanks for the detail’s explanation which is great source of Knowledge and helps alot for understanding
Will Update you soon.

 

Hi WTF & Control Guy,
This is to update you that Unit was started successfully…as WTF told,only when speed signal or L4HM was picking up then only L4ETR1 & 2 was picked up.
Thanks for support all

 

Hi WTF & Control Guy,
This is to update you that Unit was started successfully…as WTF told,only when speed signal or L4HM was picking up then only L4ETR1 & 2 was picked up.
Thanks for support all

Hi @sandeep03pradeep

Thank you for the update..