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The exhaust frame of the frame 7 is larger and there are more combustion cans than on the frame 5. The thermocouples are essentially averaged (on older controls they were averaged) by using the median temperature for control. Also, the thermocouples are compared to adjacent ones to calculate...

GE designs the characteristics of the SRV, GCV, DLN valves and the fuel nozzles, taking into consideration the fuel characteristics and site ambient conditions, as well as the turbine fuel flow requirements. They do not publish the Cv. Essentially, these valves and fuel nozzles are custom...

So, what has changed? I assume the indication was correct at some time recently. Are the LVDT readings consistent with the actual valve position (per the control specification)? Has something changed with the operator interface?

More information required! First, I assume this is a gas turbine application rather than a steam turbine application or combined cycle, with both types of turbines. If the ONLY change is upgrading the Mark V to Mark VI, then it will be hard to justify economically. However, if you are also...

Unfortunately, I don't know the details on how this improves performance. My background is controls engineering. The systems engineering organization defined what we needed to do, but I don't recall the reason it helps performance. It may have to do with the DLN combustion system. There is a...

As CSA stated, it depends: 1. If the only fuel heater is the electric heater, then the reason is to insure sufficient superheat to avoid condensation. ANY liquids in the gas fuel are poison to the gas turbine. In addition to the reasons CSA stated, liquids burning downstream of the combustion...

The reason is GE's interpretation of the NEMA standard used for their nomenclature (tagging) of devices. "65" is for a governor control, and is used for the Gas Control Valve and Liquid Fuel Control Valve. "90" is for a generic control, and is used for most of the other control servos on the GE...

1. After replacing the servo valve, did you calibrate (tune) per the control specification? 2. Have you checked the health of the interstage pressure transmitter (96FG-2, I think). Is it stable or is it drifting? 3. What is the control (Mark II, Mark IV Simplex, Mark IV triple redundant...

OK, you have Mark II Speedtronic. Do you have the ITS exhaust temperature control? If not, do you have a combustion monitor? It would seem that the trip is occurring right after the 2W warmup timer times out (based on the 30% speed at trip), although it might be after the 2F firing timer times...

Need more information: 1. What type of control is on this (MK II, MK IV, etc.)? [This is a pretty old machine if it is a 7001B.] 2. What has changed between the last successful startup and now? 3. Has the unit been on turning gear between starts? 4. What are FSR (or VCE if Mark II)...

CSA, Fortunately I never visited the Uch site. I did spend some time at Guddu, an earlier project. I am not sure why isothermal temp was increased, unless the firing temperature was also raised. The isothermal line is the exhaust temperature limit of the control curve and really only comes...

Just a little history on some of these terms: "Pickup" and "Dropout" originated in the days of electromechanical relays (Mark I and Mark II Speedtronic control). The 14HR speed relay picked up (energized) at (almost) zero speed and dropped out (de-energized) when the shaft was above zero...

FSR means "Fuel Stroke Reference" and is related to fuel control valve stroke (GCV on gas fuel, LCV on liquid fuel). Higher FSR means higher output, but it is not a linear relationship and is not the only parameter affecting output. Ambient pressure, temperature and relative humidity and heating...

The turbine speed was not raised. Turbine speed is determined by the physical size of the unit. Basically, it is a function of the tip speed of the buckets and compressor blades. It must be kept subsonic. However, higher speed translates to higher airflow and more power. So the turbine designers...

14HR will become TRUE on decreasing speed when the shaft speed drops below setpoint 'B' and will become FALSE on increasing speed when the shaft speed exceeds setpoint 'C'. So the answer to your question is the value between 'B' and 'C' is whatever it was before it enter this speed range. I.e...

NO! The MS6001B gas turbine is designed to operate at 5100 rpm. 3000 rpm is only 58.8% speed, well below the minimum speed for any heavy duty single shaft gas turbine. Even if it were possible, you would never get anywhere close to rated power. Note that GE would not go to the trouble and...

Sorry - I plead ignorance on this one. I was a controls engineer on the Speedtronic controls in the Mark I, Mark II and Mark IV period, but reference point for full LO tank is not something I ever needed to know. I had to interface with the level switches, but the settings were done by the LO...

You don't provide enough information! Has this problem occurred before? What was the LP shaft speed? Has any maintenance been done just prior to this start? Absent any other information, first place I would look is the 2nd stage nozzle control, which controls the energy split between the HP and...

The exhaust temperature control line (exhaust temperature vs. compressor discharge pressure) is a horizontal line (isothermal limit which protects the exhaust system) at lower compressor discharge pressure. At some point, the line slopes down so that the exhaust temperature limit decreases as...

Best connection point for the Bently Nevada proximity probes depends on whether your turbine is gas or steam. For a GE gas turbine, the Bently Nevada probes are used for monitoring and alarm, not trip protection (seismic probes are used for protection), so best practice is to connect the...