Signal Names used in Testing/Stroking of SRV, GCV and IGV for Frame VI Turbine using MKVI


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After carrying out rehabilitation on one of our gas turbine unit, (hot gas path inspection test). After a lot of commissioning test has been carried out on pump motors(88`s).

It is now the turn of testing the SRV, GCV and IGV. The technical guy, I think instead of going through regulator to select calibrate for stroking of SRV, GCV and IGV, but he now went through card point from VSVO slot 5 and VSVO slot 7.

The signal names are csgv, csrgv fsgr, fsg frcout and fsrout. Please i need detail explanation about all these signal names, and the exact one that he use in testing/stroking of GCV, SRV and IGV and how he carry out the operation because he is not ready to share the knowledge.
The turbine is a MS6001, a GE-design Frame <b>6</b> heavy duty gas turbine. It has a Mark <b>VI</b> turbine control system.

csgv - Calibrated IGV LVDT Position Feedback
csrgv - IGV Position Reference
fsgr - Stop/Ratio Valve LVDT Feedback
fsg - Gas Control Valve LVDT Position Feedback
frcout - Stop/Ratio Valve Servo Output
fsrout - Gas Control Valve Servo Output

I can't say exactly which ones he used for stroking, because he should have been using the AutoCalibrate Manual Position feature for stroking. Some people think that because they force analog signals in the Mark VI and Mark VIe that they SHOULD be forcing analog outputs to stroke devices (valves; IGVs)--but that's false and misleading.

Unfortunately, GE wrote NO proper procedures for stroking devices and calibrating LVDT feedback--the procedures in the Control Specification, which people only selectively follow, and without questioning whether they might be wrong or even bad, are only partially correct. And, because the Mark VI is used on so many different turbines, with different I/O and devices and auxiliaries it's not possible to write one procedure that works for ALL applications on all turbines, not even only on Frame 6 turbines--because Frame 6 turbines can have different auxiliaries and field devices which have to be dealt with during stroking and LVDT calibration/verification.

If you're looking for a procedure, you will need to develop your own. If would take weeks of back-and-forth on to help you write one, and you would have to provide a LOT of information.

If your "technician" is not helpful or forthcoming, you need to speak to his supervisor. (Be aware though--that MANY people who say they can do this or that only really know parts of the procedure and they don't know why they are doing any part of the procedure or even if any part of it is correct--it's only based on what they saw someone else do, and they may not have even seen all of what they should have seen, and they most likely didn't understand 25% of what they think they saw--so they can't really explain what they're doing or why, because they don't really know and they haven't tried to understand or think through what they think they saw. It's becoming more and more common for this to happen. If your company paid for this "contractor" or consultant to come to site, then you should be entitled to an explanation from their company about the procedures they used. But, again, if they only have "tribal" knowledge (from watching someone else who may or may not have been doing it properly!) they might not be able to say very much.