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GE 9E Mk Vie Overspeed Protection explanation
GE 9E (PG9171E) MKVIe Over speed protection explanation is required.

Can someone please explain the below protection of GE 9E MKVIe
Below I have got these from GT HMI Trip Diagram. Why there are so many protection signals related to speed. If someone can explain the below one by one.


L12HF Loss of control speed signal
L12HFD_P HP over speed fault-protective input trouble
L12HFD_C HP over speed fault-Control input trouble
L12H_P PPRO HP over speed trip
L22h_ACC PPRO Loss of protective speed signal
L12_HPW_TREA Over speed Hardware TREA
L12H_P_HW Over speed Hardware trip signal
L12H_HP_TREA Over speed TREA trip

If you have a MKVIe manual it will explain all. But, remember you have 2 x Overspeed Protection (Control & Protection) + Hardware Failures.

L12H_P	PPRO 	HP over speed trip
Set point is 110%
Only one which is easy to understand for me.


L12HF		Loss of control speed signal
L12HFD_C HP over speed fault-Control input trouble
What is mean by control speed. What is mean by this protection
What is difference between them


L12HFD_P	HP over speed fault-protective input trouble
L22h_ACC PPRO Loss of protective speed signal
What is difference between them?


L12H_HP_TREA	Over speed TREA trip
L12_HPW_TREA Over speed Hardware TREA
What is mean by TREA?
What is difference between above two?


L12H_P_HW	Over speed Hardware trip signal
Our site machine have no trip bolt. What does this protection mean?

2 out of 2 members thought this post was helpful...

Firstly I don't have manuals or drawings available to me right now. I was hoping you had but, from your questions, it appears that you don't have either. You are obviously new to Speedtronic so let's get some basics clear first.

All Speedtronic has Control and Protection and they are two totally separate items. Specifically, for Overspeed, we have 2 systems, One overspeed from Control using 3 x dedicated Speed Pickups and one from Protection using another 3 x Speed pickups, so totally separate Electronic Overspeed systems.
>

L12HF		Loss of control speed signal
>L12HFD_C HP over speed fault-Control input trouble
What
>is mean by control speed. What is mean by this protection
>What is difference between them.

L12HF = Loss of Control Overspeed signal, could be a loss of a speed pick-up or something in the hardware.
L12HFD_C = Loss of a Speed pick up in the Control Overspeed

>

L12HFD_P	HP over speed fault-protective input trouble
>L22h_ACC PPRO Loss of protective speed signal
What is
>difference between them?

Same as above but this time in the Protection Overspeed system (PPRO is the Backup Overspeed card)

>

L12H_HP_TREA	Over speed TREA trip
>L12_HPW_TREA Over speed Hardware TREA
What is mean
>by TREA?
>What is difference between above two?

12H_HP_TREA = TREA is a terminal board. An Overspeed event has happened.
L12_HPW_TREA = Some problem with hardware connected to TREA

>

L12H_P_HW	Over speed Hardware trip signal
Our site machine have no trip bolt. What does this protection mean?

Why are we talking about Overspeed Bolts? We have 2 x totally separate Electronic Overspeed systems. That's why we don't have a bolt. This Alarm means that something in the Electronic Overspeed hardware caused a trip.

Hope this helps. I reckon you need to a bit of reading as you don't seem to have any concept on how MKVI/e works.

Thanks dear, It helps.

Basically I am not a control related specialist, but trying to learn/understand the fundamentals related to GT/ST/Transmission related control systems. So please don't mind if it seems very basic to you.

I could not find the detail trip logic about speed in logic diagrams of gas turbine.

In Printed form logic diagrams (printed from MK Vie), there is a logic block which generate above trip signals for master protective trip block. But detail of logic related to Speed is not there.

I suppose that there will be standard logic (about speed protection) for all similar GE machines. I have a bunch of documents and have been trying to find related document. Can anyone name or document number from where I can find these information?

I have find that control.com is the ever best forum for learners and professionals to find the correct answer of there questions.

Do Have MKVIe manuals? Post your Email and I can send you a few documents.

I do have documents but you can share at kashifali069@gmail.com.

1 out of 2 members thought this post was helpful...

kashifali,

Frame 9E GE-design heavy duty gas turbines don't usually use TREA terminal boards, which are designed and primarily used for aeroderivative gas turbines. In general, TREG cards are used for heavy duty gas turbines. (Having said that, GE Belfort has been given responsibility for Frame 9 heavy duty gas turbines, and they have been known to do just about anything just because they can, so it's possible they might have used TREA cards.)

GE has a habit of designing one thing that can be used for many different applications. And, software blocks are no different--in fact, it's even easier to build software blocks which can be used for LOTS of different applications with a few different permissives. What is the name of the block you are trying to understand?

In your first post you said you were looking at GT HMI Trip Diagrams. For a GE-design Frame 9E heavy duty gas turbine? Could the Trip Diagram have been for an aeroderivative gas turbine (such as an LM6000, or an LM2500)?

You mentioned you are looking at a print-out of the application code. Those can be VERY difficult to read and understand, and even more difficult to learn from. And, because of their known penchant for using one block for many different applications only some of the inputs and outputs of the block may be used in any particular application. So, while signal names may appear on a block it doesn't mean that ALL the signal names are actually used for any block.

The TREx card is usually only one of two cards used in the fuel stop valve circuit. You need to know what TREx card is used in a particular panel and then you can go to GEH-6721, Vol. II, and start to understand how the cards are connected to the fuel stop valve circuits.

I believe several of the signals you listed are signals used in some overspeed blocks which compare the primary speed pick-ups signals to the emergency overspeed speed pick-up signals and generates Process Alarms when the error exceeds some amount--to alert operators and technicians to possible problems with speed pick-ups, speed pick-up wiring, or input cards (the latter would also be accompanied with Diagnostic Alarms).

Mark VIe is not a subject which lends itself to learning without some kind of introductory training, and a lot of hands-on experience. And, it really helps if you have a colleague that has some experience and is willing to share it with you.

The GE turbine control community here at control.com has been active for nearly 15 years, maybe a little longer. LOTS of questions have been asked--and answered--over that time, and they are all available for reviewing using the cleverly hidden 'Search' feature at the far right of the Menu bar of every desktop control.com webpage. (Use the Search 'Help' the first couple of times you use the feature; the syntax isn't like your preferred World Wide Web search engine--but it's just as powerful and fast.) You can find a LOT of information, perhaps not exactly what you were looking for, but even more than you thought was possible on such a free forum.

We are here to try to answer questions and provide clarity. But, we also may ask questions to help us understand exactly what it is you are asking so we can be as precise as possible (again, reading past threads can be very helpful to understanding how information is presented and how to ask questions here on control.com).

Welcome to the forum!

>What is the name of the block you are trying to understand?

Logic block is L12HVI from where some (L12HF,LHFD_P, L12HFD_C) signals are out and goes to trip logic block L4PSTX3.
Remaining signal from original post are directly input to L4PSTX block

>In your first post you said you were looking at GT HMI Diagrams. For
> a GE-design Frame 9E heavy duty gas turbine?
Could the Trip Diagram have been for an aeroderivative gas
turbine (such as an LM6000, or an LM2500)?

Trip diagram of PG9171E Mark Vie

L12H is another overspeed signal to L4POST, beside the original post.
Want to know why so many separate signals for overspeed trip.

Remember it's quite a complicated system. You have two separate O/speed systems + a lot of hardware verification. Overspeed has got to be totally 100% reliable and has got more and more complicated as each Mark version arrived. It also has got to allow the removal of the mechanical Overspeed and have two totally separate electronic overspeeds.

0 out of 1 members thought this post was helpful...

Kashifali,

If the Mark VIe doesn't have a TREA card, then you can ignore the signals and code for a TREA.

If the unit doesn't have a mechanical overspeed bolt, then you can ignore the signals associated with the mechanical overspeed bolt.

The "control speed signal" description refers to the speed pick-ups connected to <Q> (<R>, <S> and <T>). (In very old versions of Mark* Speedtronic turbine control systems, speed pick-ups used for control functions were designated as 77HC-n, the HP Shaft Control Speed sensors where "n" is the number of the redundant speed sensor (for example, 1, 2 or 3). And the speed sensors associated with overspeed sensing and tripping were designated as 77HT-n. And, then along about the time the Mark IV came out, the speed sensors for the control function AND the primary electrical overspeed detection and tripping were designated as 77NH-n. And, when the Mark V included a second, emergency/back-up electrical/electronic overspeed the speed sensors were designated sometimes as 77HT-n.

When the Mark* has two electrical/electronic overspeeds the designers thought it would be a good idea to have the two overspeed functions compare their respective speed signals--and generate Process Alarms if there was a disagreement. This to try to alert (conscious) operators and technicians to a problem or problems.

Hence all of the "maximum case" signals you reported and see. Personally, I would NEVER trust what I see on any CIMPLICITY display unless I had verified the display exactly matched what was in the application code. There have been TOO MANY cases of incorrect displays--and it's the application code that determines how the turbine is operated and protected, NOT the CIMPLICITY display. Unfortunately, CIMPLICITY displays (or PROFICY displays or whatever they are called these days) are NOT automatically produced from the application code. They have to be MANUALLY edited to make them reflect the application code which is running in the machine the HMI is monitoring.

So, getting back to my point--GE likes to use a "one-size-fits-all" (sometimes called "max (maximum) case") design philosophy, which can be very confusing when someone is first trying to learn and understand the GE turbine control system. Believe me when I say that the Mark VIe is infinitely better in this regard than the Mark V and an improvement over the Mark VI also--so consider yourself lucky to be working on a Mark VIe which doesn't have NEARLY the "max case" code and Constants as previous generations (Marks).

Hope this helps!

I would also like say thanks to Glenmorangie and CSA for the guidelines.

I have been reading the past post from search of control.com
It helps a lot..

Hi,

CAN I have documents but you can share at HBNBIL07@GMAIL.COM.