E
Can a GE Frame Gas Turbine be started and run without the auxiliary hydraulic pump starting?
3
309EGuy
What frame size of turbine?
Probably could be started for B/E class, although some logic forcing may be needed. Many Frame 5 and Frame 6 were shipped with out auxiliary hydraulic pumps. Crank speed would develop enough hydraulic oil pressure from the gearbox driven hyrdaulic oil pump.
Come to think of it I dont recall a low hydraulic oil pressure trip when running. There is a L86HD hydraulic trouble signals that starts the 88HQ pump, if installed, but doesnt trip the turbine. I've seen units run with hydraulic oil pressure at half nominal value. What will take you out is IGV or Gas valve position errors if the pressure drops to low. It is normal for the AHOP to turn off just before full speed. I'm not sure how an F class would handle it as I've no experience with them (yet).
Probably could be started for B/E class, although some logic forcing may be needed. Many Frame 5 and Frame 6 were shipped with out auxiliary hydraulic pumps. Crank speed would develop enough hydraulic oil pressure from the gearbox driven hyrdaulic oil pump.
Come to think of it I dont recall a low hydraulic oil pressure trip when running. There is a L86HD hydraulic trouble signals that starts the 88HQ pump, if installed, but doesnt trip the turbine. I've seen units run with hydraulic oil pressure at half nominal value. What will take you out is IGV or Gas valve position errors if the pressure drops to low. It is normal for the AHOP to turn off just before full speed. I'm not sure how an F class would handle it as I've no experience with them (yet).
The answer is a qualified 'yes.'
I'm hearing some new Frame 9E's need the Aux. Hyd. Pump to help break the shaft away from zero speed. If the unit at your site is one of these machines, the answer would then be,"No."
The qualified 'yes' would be that the Main Hyd, Pump output pressure & flow would have to be sufficient to operate the fuel stop and -control valves at firing speed. My experience is that the flow and pressure would be sufficient, but all machines are not exactly similar.
There was no sequencing in Speedtronic control systems in years past to prevent a start if the Aux. Hyd. Pump wasn't running. However,the 'Bunch from Belfort' have a real knack for fixing things that were never broken, and an even better "talent" for complicating the simplest of tasks and functions and "logic" to the point of being downright painful to be involved with.
I don't believe the machine would be damaged by attempting to start it without the Aux. Hyd. Pump running. The Aux. Hyd. Pump is shut down when the unit reaches 95% speed, so running the unit without the Aux. Hyd. Pump would only be a problem if the Main Hyd. Pump, or its coupling or drive shaft failed .
Write back to let us know if your attempt was successful.
I'm hearing some new Frame 9E's need the Aux. Hyd. Pump to help break the shaft away from zero speed. If the unit at your site is one of these machines, the answer would then be,"No."
The qualified 'yes' would be that the Main Hyd, Pump output pressure & flow would have to be sufficient to operate the fuel stop and -control valves at firing speed. My experience is that the flow and pressure would be sufficient, but all machines are not exactly similar.
There was no sequencing in Speedtronic control systems in years past to prevent a start if the Aux. Hyd. Pump wasn't running. However,the 'Bunch from Belfort' have a real knack for fixing things that were never broken, and an even better "talent" for complicating the simplest of tasks and functions and "logic" to the point of being downright painful to be involved with.
I don't believe the machine would be damaged by attempting to start it without the Aux. Hyd. Pump running. The Aux. Hyd. Pump is shut down when the unit reaches 95% speed, so running the unit without the Aux. Hyd. Pump would only be a problem if the Main Hyd. Pump, or its coupling or drive shaft failed .
Write back to let us know if your attempt was successful.
