Hi to everyone!

We have a MS6001 with a MK V control.

The thing is that the GT had not been ignited in 6 months, for different reasons (but not because of any trip or failure, mostly because of bureaucracy). When trying to start it with natural gas this monday, when reaching ignition speed (around 1200 RPM), the SRV and GCV valves did not open, causing an ignition failure.
I thought that the most likely would be dirty oil from the sump, so we decided to change the oil, change the PALL filter before the MOOG valves, and in turn, both MOOGs were also changed for new ones (the old ones were left for repair in the workshop).
I did an autocalibration of the valves with the unit out of service (doing all the previous forcing required obviously). The SRV did not move, but the GCV did.
I decided to do a startup test with the GT, starting first in crank mode, but the problem was that the SRV did opened, but at 200 RPM, causing an immediate trip due to excessive fuel prior to ignition.
What could be causing this? I understand that in crank mode, gas valves opening signals are not even sent by mark V.
Why can't I move the SRV in autocalibration?

Hope you can help me with this!

 

Mauricio Marquez,

Foremost, when replacing an electrohydraulic servo-valve (a "servo") IT IS NOT NECESSARY to calibrate anything using AutoCalibrate. Autocalibrate ONLY changes LVDT feedback--NOTHING ELSE!!! Full stop. Period.

What IS important to do when changing a servo-valve is to perform a servo current polarity check--but NOT using the method in the Control Specification. The instructions for perform servo-valve polarity checks have been written and described in detail MANY TIMES on Control. com, so I'm not going to do it in this thread again. Use the 'Search' feature of Control.com and find any one of many detailed write-ups on performing servo-valve polarity checks and read them, and ask questions if you don't understand.

Using the AutoCalibrate function of a Mark V to calibrate a SRV (Stop-Ratio Valve) is very simple. One has to establish L.O. pressure (usually by running the Aux. L.O. Pump in HAND). Then one needs to establish hydraulic pressure for the SRV to be opened--this requires some Logic Forcing. Specifically, it requires forcing L20FG1X to a logic "1", forcing L20TV1X to a logic "1" and forcing L4_XTP to a logic "0." This AFTER closing the gas fuel manual isolation valve upstream of the SRV AND venting the fuel and pressure out of the line between the manual isolation valve and the SRV. (Safety first!)

Then you can go to the SRV screen in AutoCalibrate and with the above logic signals forced you should be able to enable the manual positioning ("stroking") feature of AutoCalibrate and move the SRV to whatever position you want it to move to. Then follow the procedure you found using the Search feature of Control.com to move the SRV to, say, 50% stroke (position) and start disconnecting the servo coil wiring while observing the SRV to see if it stays open (it won't stay at EXACTLY the 50% stroke position as you disconnect servo coil wires, but it should NOT go closed--if it goes closed, then there's some wrong with the polarity of the servo current being applied to one or two coils and it needs to be reversed and re-tested).

I have no earthly idea why the SRV moved when the unit was in CRANK mode and you pushed the START button (was something forced that shouldn't have been ???). Further, while it should not have moved if it did open it should NOT have opened very far since if there was gas fuel supply pressure upstream of the SRV the pressure downstream of the SRV (and upstream of the GCV) would have spiked very quickly--even if 20VG-1 was open, and especially if it was closed! So, unless there was NO gas fuel pressure upstream of the SRV the unit should NOT have tripped on "excessive fuel flow" (which is a bogus alarm text message, by the way).

Again, when replacing servos it IS NOT necessary to calibrate anything. AutoCalibrate ONLY calibrates LVDT feedback, and replacing the servos does NOTHING to affect the physical stroke of the device or the LVDT position/feedback. Further, "calibrating" LVDT feedback unnecessarily can result in lots of problems with starting and acceleration and loading. (It should be noted that the SRV is a pressure control loop, not a position control loop--but the GCV IS a position control loop. The SRV will be moved by the Mark* to whatever position is required to make the P2 pressure (the pressure between the SRV and the GCV) whatever it needs to be to be equal to the P2 pressure reference. If that's 4.2% position, then the Mark* will move the SRV to 4.2% position. If that's 23.7% position, the Mark* will move it to 23.7% position to make the P2 pressure equal to the P2 pressure reference.

When actually trying to START the unit (establish flame), the unit will go through the purge sequence and at the completion of the purge time the ignitors (the "spark plugs") will be energized, and the GCV will open first, then the SRV will open. This is done so that the pressure between the SRV and the GCV doesn't build up too high in the beginning because the GCV is open first and the SRV opens to whatever position it needs to open to to make the actual P2 pressure (usually signal name FPG2 in a Mark V) equal to the P2 pressure reference (usually signal name FPRG in a Mark V). At the completion of the firing timer the ignitors (the "spark plugs") will be de-energized (presuming flame was established). As the speed of the unit increases, the P2 pressure reference will also increase--which means the SRV opening will continue to increase in order to make the actual P2 pressure equal to the P2 pressure reference. Once the unit is synchronized and loaded, the GCV will open to increase the load on the unit. This will tend to cause the P2 pressure to decrease--but the SRV will open to keep the actual P2 pressure equal to the P2 pressure reference--during both loading and unloading. The SRV will change position as necessary as the GCV opens and closes, and as the gas fuel supply pressure changes (which it might do depending on conditions from the gas fuel supplier and/or compressor).

It would probably have been wiser after the first failure to ignite, to use the manual feature of AutoCalibrate to stroke (open/close) the SRV and GCV (after closing the gas fuel manual isolation valve!) to make sure they would move BEFORE changing the servos but after changing the filters. And, again, changing servos--contrary to very popular, and false, belief--does NOT require "calibrating" anything!!! I would also suggest checking the intervalve vent solenoid, 20VG-1, to be sure that it is working correctly. Usually, the valve is open when the unit is not running, and during STARTing it is closed in anticipation of opening the SRV, and it remains closed during normal operation.

You would also do well to use VIEW2 to capture data during your next START attempts, and then you can post the data files here to Control.com for us to analyze and comment on. Without actionable data (such as from VIEW2) it's often difficult to say what happened. We also need to know ALL alarms which are active prior to and during the START attempts. If you really want good help.

Finally, does this machine ever run on liquid fuel? If so, how often?

Hope this helps! Help us to provide better help by giving us the requested information and actionable data (such as from VIEW2).

 

First of all, thank you very much for answering, I have read many of your threads and I have learned a lot from you and from this wonderful page.
Continuing with the topic, I think I explained badly and I lack information to deliver ...

After the failed ignition of which I speak, I did test the servo valves with Auto-calibration (with this I also explained badly, I wanted to say that I entered the Auto-calibration function, but NOT that I Auto-calibrate them, I moved them with ENABLE MANUAL, AND MANUAL SET), Well, none of them moved… after this, I decided to install new ones.

I also put both pumps into service (88QA-1 and 88HQ-1), we close the gas isolation valves and we also vent the gas in between to the atmosphere (safety first as you say !!) before entering Auto Cal.
We also perform the forcing on the gas and IGV trip valve (just in case) L20FG1X / L20TV1X = 1, and on L4_XTP = 0 to be able to move the servos (forcing L4 = 1 is also a requirement?).
What happened in Crank mode is quite strange, in LOGIC FORCING, I made sure that I did not have anything forced (by pressing UNFORCE ALL). How do I know if there is another signal forced?

The alarm screen shows "trip due to excessive fuel", and Pre ignition Trip (L4PRET) and Pre ingnition trip auxiliary (L4PRETX) appear on the trip screen.

The machine does run on diesel fuel, but as I say, it was out of service for more than 6 months (diesel runs are less frequent than with gas in any case).

After installing the new servos, I entered the Autocal function again, and did a manual stroking of the valves, GCV moved well, but SRV dont moved at all... Maybe here I made a mistake, because after SRV did'nt move, I did an AUTO CALIBRATION of the SRV thinking that this way I could solve the problem (now reading your explanation I understand that AUTOCALIBRATE does not work for that), You even explain to me that this can cause problems with the starting and acceleration of the turbine, ouch.

I know that the mark V first commands the GCV servo to open, and then the SRV ... but this is very strange and had never happened, I recorded a video where the opening and closing of the SRV servo is clearly seen (causes an immediate trip ), maybe I upload this video to youtube.

This turbine does not have the 20VG1 vent solenoid valve ... it only has a manual vent valve.

Tomorrow I will do more tests and record information with VIEW2 to upload it too.

I thank you enormously for the explanation about AUTO CALIBRATE, about the SRV and the P2 pressure ... I think I have learned much more from this page and its threads, than from the GE manuals, the explanations are more accurate and direct. I will search the forum about the polarity check of the servos.

Many thanks CSA!!!

 

Thank you for the information. Better late than never.

I have NEVER seen a GE-design heavy duty gas turbine without a solenoid-operated vent valve between the SRV and GCV. Do you have to manually operate the valve each time the turbine trips or is shut down? Because when the GCV closes and the SRV closes there WILL BE gas pressure trapped between the two valves--which will almost always result in a hard lite-off during the next START if the pressure is not vented out. (A leaking SRV--and many of them do leak!--can also cause this problem of hard lite-offs and booms in the exhaust when STARTing.) I will say I have not seen EVERY GE-design heavy duty gas turbines, but I have seen my share of them, packaged by GE and by companies licensed to package the turbines and they quite often do some "unusual" things with auxiliaries, but I have not ever seen a single GE-design heavy duty gas turbine without a solenoid-operated vent valve between the SRV and GCV. So, this would indeed be a first--for me, anyway.

That alarm "START-UP FUEL FLOW EXCESSIVE" is bogus because the gas fuel flow-rate is NEVER compared to any Control Constant to check to see if the flow of fuel is excessive during starting. All that causes that alarm is that the SRV position is compared to a Control Constant and if the SRV position is greater than the Control Constant the ASSUMPTION is that the valve is open too much and the gas fuel flow-rate would be excessive (if gas fuel was actually flowing). If there was that much gas fuel flowing (based on the opening of the SRV) the exhaust temperature would go very high--probably high enough to at least cause an exhaust temperature high alarm, and maybe even an exhaust overtemperature trip (if the ignitors actually ignited flame).

You know that 20FG-1 and the hydraulic dump valve in the gas fuel trip oil (sometimes called control oil) circuit have to be working to get hydraulic oil to the SRV servo and the SRV hydraulic actuator. I have seen the "poppet" in 20FG-1 get gummed up with oil which hasn't been flowing for a long time and cause that valve not to allow hydraulic oil to get to the dump valve and to the servo and actuator. So, if you're using AutoCalibrate to stroke the SRV but it's not moving, then something is preventing high-pressure hydraulic oil from getting to the SRV servo and actuator. Look at the Gas Fuel and Trip Oil (Control Oil) P&IDs to see the components and then remove the cover from the side of the base of the combined gas valve assembly (I'm presuming the unit has a Y&F (Young & Franklin) combined gas valve assembly.) Sometimes removing 20FG-1 and the hydraulic dump valve and disassembling them and cleaning them very well before reassembling and reinstalling them will work wonders.

I still have no explanation why the SRV moved at 200 RPM while the unit was in CRANK mode.

I will tell you this about the Logic Forcing Display: When it is open (ANY time it is open) it is asking the Mark V at a very high rate for the names of any logic signals which are forced. It creates a LOT of traffic on the StageLink when this is going on--a LOT of traffic. Even if no signals are forced--the display asks many times a second for the names of any forced signals. So, it's NOT a good display to use for monitoring signals--even if none of the ones you are monitoring are forced; it just keeps asking and asking and asking, as long as it's open. And, depending on what's going on with the unit and alarms and such it can really cause problems.

If it were me, I would remove 20FG-1 and the gas fuel dump valve (sorry; I can't recall the device number for it) and disassemble and clean them. They are pretty easy to remove and disassemble; they have o-rings and springs and it's kind of hard to damage them (though some people have managed to do so--but I think they're Viton or maybe Buna-N, so they shouldn't be too difficult to find locally). I would then re-install them and start with forcing the requisite signals. If nothing still happens, I would then remove and do the same to 20TV-1 (it's essentially the same valve as 20FG-1). AND, if the unit has a mechanical overspeed bolt, I would be manually tripping and resetting that several times as well, because it, too, can get gummed up with a lot of oil vapours and humidity in the Accessory Gear Box. And, then I would try to just let hydraulic oil pressure and Trip Oil (Control Oil) pressure build up and see if the SRV will open. You will probably have to use the Manual feature of AutoCalibrate to get the SRV to open, but just give it a reference of 110%--and see what happens. It should move; if it doesn't, then there's really something wrong--up to and including problems with the servo current being applied from the Mark V to the servo coils.

So, that's about all I can add. We'll wait to hear back from you. Good luck!

 

Mauricio Marquez,

Can you please post at least the portion of the Gas Fuel P&ID showing the area between the SRV and GCV? There should be a "tap" there for the P2 pressure transmitter(s) (some units have just one; others have three--P2 pressure transmitters (96FG-2A, and -2B & -2C if there are three transmitters). There should also be a three-way valve to connect the "tap" to the P2 pressure transmitters, OR to vent the P2 pressure transmitters to atmosphere (a lot of technicians use this valve to connect a pressure source for testing the transmitters, and then promptly forget to return the three-way valve back to the "running" position... which usually results in "EXCESS START-UP FUEL FLOW" alarms/trips...). There should also be a solenoid-operated valve, 20VG-1, a normally-open valve which is energized to close. The "vent" position of the three-way valve AND the outlet of 20VG-1 should go to a goose-neck vent to atmosphere on the top of the Gas Valve Compartment (the vent is called a goose-neck vent because it is a 180-degree piece of pipe of tube that exhaust down to prevent water and such from entering the vent pipe).

Again, the opening and closing of that intervalve (P2) vent valve, 20VG-1, should be automated and controlled by the Mark*--it shouldn't be a manual operation. It would be really interesting to see the gas fuel P&ID that shows the P2 intervalve area and all of the connections to it.

Thanks!

 

Dear CSA, I am very sorry, I made another mistake giving you specific information, the turbine has a 20VG-1 solenoid valve (I made a mistake out of ignorance), after your second message I found that SV and the goose neck vent outside the gas compartment. I thought you were talking about the upstream venting of the SRV (this is a manual venting valve). I don't know if this vent comes with the gas compartment or if it was made here.

Just to excuse myself, I can tell you that in this plant we have 2 Siemens SGT-800s, 1 Alstom combined cycle with a GT26 from Ansaldo and an Advant control DCS from ABB, 4 steam power plants from Mitsubishi, with M701DA steam turbines ( 2 of these plants with Mitsubishi Dyasis Netmation DCS control, and 2 with SPPA T3000 DCS from Siemens).
As you can see, many different control loops, lots of P&ID’s, and too many different control systems.
I've been in the company for 12 years, and I still learn new things every day.

After that sad excuse, another one ... the MS6001 was bought here in the company in 1993 (I was 9 years old at that date), only with diesel fuel ignition! the gas ignition system was only adapted in 1999, I have looked for documentation on the gas system and its components, its PI&D, but the only thing I can find is the original GE documents with the MS6001 without gas ignition system (I am consulting former workers and retirees of the I&C area for the documentation or diagrams, if they remember where it is or was stored, I still cannot find something).

I will upload the Trip oil diagram where only the 20TV and 20FL appear.


I have not been able to find the location of the 20TV-1 in field... I can see the Moog servo of the IGV, its LVDT's and its oil filter, but not the SV ... it is in this location (IGV compressor compartment) or elsewhere?

On Saturday, we disassembled the SRV hydraulic block, the hydraulic piston and the 20FG-1 (as you recommended), a bit of dirt was found, but nothing to indicate that the problem was there, the parts moved smoothly (it served to rule out possible failures though).
What I did find was that by forcing a 1 to 20FG-1 in Logic Forcing, from the PTBA core <P> board (points 59/60) the 125 VDC voltage is NOT coming out to the solenoid valve. I also tried with 20FL-1, still there is no output voltage.
I measured the fuses on the core <P> cards, at least the ones I was able to remove, all good, today I will keep checking this problem, which seems to be the most important (this is strange too, because in the previous days I was able to move the GCV in manual mode, and I can't do if I don't force the 20FG-1 valve to logic 1, right?).

I also uploaded 2 videos to youtube to demonstrate the behavior of the SRV during a start up in crank mode. (

and

).

The other thing I wanted to check is that in the SRV, the servo model is G771K235A and in the GCV it is G771K200... I have not been able to find in the ordering codes those last numbers (in a moog PDF it said that those numbers were the designations of the models assigned at the factory, but they do not specify what differentiates them).

I will continue looking for possible failures (the output to 20FG-1 problem) and following all your advice.

I will post new results if I find them.
Many thanks for your precious help CSA!! , I'll be in touch.

 

Mauricio Marquez,

The 125 VDC that comes out of the <P> core for the fuel stop valve solenoids is the result of the PTRs (Primary Trip Relays) and the ETRs (Emergency Trip Relays) BOTH being energized at the same time. The PTRs for 20FG-1 are usually energized by forcing L20FG1X to a logic "1", and the ETRs (for both 20FG-1 and 20FL-1) are energized by forcing L4_XTP to a logic "0." (Never, NEVER, EVER force L4 to a logic "1"--NEVER EVER!!!) The ETRs supply the +65 VDC for the fuel stop valve solenoids, and the PTRs supply the -65 VDC for the stop valve solenoids. BOTH the PTRs and the ETRs for each of the fuel stop valves have to be energized for the positive and negative voltage/current to get to the fuel stop valve solenoid to energize the solenoid. You can watch this by watching the pressure gauges for the Trip Oil pressures for each fuel. For gas fuel, watch the gas fuel trip oil pressure gauge while you first force L20TV1X to a logic "1" and force L20FG1X to a logic "1" and then force L4_XTP to a logic "0". You will see the Trip Oil pressure build up to (usually) around 50-60 psig. Then force L20FG1X to a logic "0" and the Trip Oil pressure should go pretty quickly to zero psig. Reforce L20FG1X to a logic "1" and the Trip Oil pressure should build up again to approximately 50-60 psig, and then force L4_XTP to a logic "1" and the Trip Oil pressure should quickly go to zero psig. You can also force L4_XTP back to a logic "0" and then force L20TV1X to a logic "0" and it's pretty likely the Trip Oil Pressure will quickly drop to zero psig. Unforce all the signals (L20TV1X, L20FG1X and L4_XTP) and that tests the ability of the Mark V to establish Trip Oil pressure for the gas fuel system--which is necessary to get the SRV to open and move using AutoCalibrate.

SOME GE-design heavy duty gas turbines DID NOT require 20FG-1 to be energized (or even 20TV-1 to be energized) to be able to move the GCV (since it's not a fuel stop valve). One only had to establish L.O. pressure and hydraulic pressure and then go to AutoCalibrate to be able to stroke the GCV. But, NOT ALL GE-DESIGN HEAVY DUTY GAS TURBINES WERE EXACTLY ALIKE!!! So, most people just always forced 20FG-1 and 20TV-1 (and L4_XTP) when stroking any gas valve and usually it worked for all the gas valves. (The P&IDs have all the answers for any unit; most people just don't want to take the time to look and understand what a particular unit does or does not require--so they just force "everything" all the time...!)

Finally, the signal names I'm providing are the "typical" signal names which were used for many, many years with Mark IV and Mark V turbine control systems. Sometimes, the signal name for 20FG-1 was L20FGX, or for 20TV-1, it was 20TVX or 20TVX1. L4_XTP was ALWAYS L4_XTP, though. So, while the signal names I'm supplying may actually be in the control signal database for the unit at your site, they MAY NOT be the actual signals used for the solenoids at your site. The IO.ASG file defines the signal names for the solenoids at your site. This may also be part of the problem you are having with the SRV, trying to stroke it; I don't know.

I'm not near any Mark V software but there was a PROM version out that required another signal to be forced to a logic "1", if I recall correctly, but I can't exactly recall the name of it. I think it was something like L94HPT_BYP--but, I'm sorry, I just can't recall it exactly right now. Tomorrow I should have the ability to access some Mark V software and I will try to look up the correct signal name.

But, that should be it--as far as I recall (it's been a long time, and getting longer...).

20TV is usually mounted on the top of the L.O reservoir, very near the Aux. Hyd. Pump. Again, it looks very similar to 20FG-1 and 20FL-1.

The hydraulic dump valve I was referring to is under the combined SRV/GCV assembly, next to where the SRV servo is located. It usually has a shiny spring that is visible and is a shiny metal block. If I recall correctly, there is one for the Liq. Fuel Stop Valve, also, and since you can't find the P&ID for the Gas Fuel system, you should be able to find it on the P&ID for the Liquid Fuel System. It's just a "shuttle" valve that requires more than approximately 20 psig to overcome the spring tension to allow high pressure hydraulic fluid to get through the dump valve to the hydraulic actuator of the SRV (in this case). (Trip Oil pressure is what supplies this greater-than-20 psig pressure.)

The part numbers you are listing for the servo valves are the Moog part numbers; I don't have a secret decoder ring for them. Sometimes (but not always) on the Parts List drawings for the servos they listed the Moog part numbers. If the servos were purchased from GE they usually had both Part Numbers on them--the GE P/N and the Moog P/N. Servos have different flow-rates for different applications, and different ports for different applications. Again, I just always went by the GE P/N and everything was always okay.

There was some sequencing problems which I seem to recall which actually resulted in a partial opening of the SRV during CRANKing. It was difficult to find the cause, but GE did correct that bit of logic--though probably not in all machines. And, if someone other than GE did the sequencing changes--and used the incorrect logic from a different unit when making the sequencing changes for gas fuel--then that could be part of the problem. If I recall correctly, one way the SRV could be opened when CRANKing was if someone had selected FIRE or AUTO or REMOTE prior to then selecting CRANK before giving the unit a START command. Something in the sequencing latched up the logic to energize 20FG-1 when the unit would reach L14HM which would cause the SRV to open. But the videos are showing the SRV to go REALLY open--which is causing the P2 pressure to rise very quickly, and I suspect there is something amiss with the polarity of the servo currents being applied to the SRV servo coils--at least two may be incorrect. BUT, really, I would need to see the CSP to be sure of what might be happening to cause the SRV to open during CRANKing, but I probably couldn't explain why it's opening SO FAR when it is opening. The P2 pressure reference when initially starting and I think when CRANKing is either -40 psig, or -25 psig; sometimes it was 0 psig. But something sure seems a little off there--I just can't say exactly what, but it's probably more than one thing, really.

Hope this helps!

 

CSA, good morning.

I finally found the problem (and the solution), I am a bit ashamed to write it, but I will do it in order to be aware of the error in case the same thing happens to another person.

After ruling out the voltage problem towards the 20FG-1 for what you explain in your previous message (that in addition to L20FG1X, it was also necessary to force the L4_XTP signal so that the ETR relays are activated and send the full DC voltage to the SVs).

Something was causing the oil to pass directly through the servo and push the hydraulic piston towards its opening as soon as the turbine accelerated, even in Crank mode (we already ruled out a fault in 20FG-1, and the hydraulic dump valve).

I started to think about the Moog servo model codes (G771K235A for SRV, and G771K200 in GCV), and I remembered that in some field transmitters of some brands, the last numbers correspond to where the electrical connector is mounted, or where it points to.

Stupidly, I was guided by how the previous servo was mounted on the SRV (with its connection towards the side where the 20FG-1 is), but just yesterday, I finally found a diagram of the gas module that made me doubt its position.
The servo of the SRV was mounted as the diagram indicates, but the servo of the GCV is with its connector to the other side, with respect to how we really have it physically.... so I took out the moog (for SRV), and observed its hole patterns, and I realized ... it was mounted the other way.





Now we have both servos, with their coil cable outlet towards the front of the gas module, and not as indicated in the diagram, and all because they are different servo models.

I did tests in Autocal and manual mode, and the SRV responded, at all points on its range of motion.

The turbine started (P2 pressure was steady at 4 Kg/cm2), reached 5100 RPM without problems, and also synchronized without problems (P2 pressure rose to 17 Kg/cm2 at 35 MW, and P3 was 6 Kg/cm2).



It must be said that I felt quite silly, for not paying attention to the most obvious, the position of the servo with respect to its holes A, B, P, T, and G ... but hey, it can also be said that I learned many things that I did'nt knew (in the failures is when you learn the most, they say).

I hope this thread is useful for those who make this absurd mistake, as well as me (always check for the servo codes before ordering) and, the hole patterns ...

I say goodbye, and I thank you CSA once again for the knowledge that you gave me, and delivered to this forum.

Thanks for all!

 

Thank you for the feedback--that is the most important contribution here at Control.com!!!

Yes; orientation is important, and with servos it's very important. I am very glad everything is all good now!

Felíz Navidad!

 

Hi to everyone!

We have a MS6001 with a MK V control.

The thing is that the GT had not been ignited in 6 months, for different reasons (but not because of any trip or failure, mostly because of bureaucracy). When trying to start it with natural gas this monday, when reaching ignition speed (around 1200 RPM), the SRV and GCV valves did not open, causing an ignition failure.
I thought that the most likely would be dirty oil from the sump, so we decided to change the oil, change the PALL filter before the MOOG valves, and in turn, both MOOGs were also changed for new ones (the old ones were left for repair in the workshop).
I did an autocalibration of the valves with the unit out of service (doing all the previous forcing required obviously). The SRV did not move, but the GCV did.
I decided to do a startup test with the GT, starting first in crank mode, but the problem was that the SRV did opened, but at 200 RPM, causing an immediate trip due to excessive fuel prior to ignition.
What could be causing this? I understand that in crank mode, gas valves opening signals are not even sent by mark V.
Why can't I move the SRV in autocalibration?

Hope you can help me with this!

can you suggest me a good vendor to purchase GE turbine parts with good price?

 

hussainify598,

Please open a new thread for this unrelated question (unrelated to this thread's topic).

It would also be very helpful if you would be more specific about the parts you wish to purchase--for example, spark plugs, or pressure transmitters, or fuel nozzles, or combustion liners, or second stage nozzles, or first stage shroud blocks, or Mark* cards, etc. Not every vendor has all parts or can get all parts (without paying extra costs which would be added to the price you would pay). Help us to help you.

Thank you!!!