Dear All,
Machine : GE MS5002C
Control system: Mark VIe TMR
we just completed Zero overhaul
Indications
1- Control oil pressure drop to 58 PSI
2- Nozzle current suicide @ 2.5 degree if we increase the LP speed fast
Observation:
- during start up the control oil pressure stay at 110 PSI.
- at LP speed 95%, auxiliary pump stopped and pressure dropped to 90%
- Control oil pressure gradually decreasing to 58 PSI within 2 hours
- Lube oil pressure steady at 150 PSI
- Hydraulic pressure steady at 1220 PSI
- during calibration the nozzle acting perfect and no deviation between the Ref and position feedback
- during the startup the current suicide happened and gap between Ref and feedback exist and the LP speed go back to 70%
- we should increase the LP speed slowly to avoid current suicide
Action taken so far:
- checked and replaced the Lube oil filters
- replaced the hydraulic filters and hydraulic GCV filter
- checked the Dump solenoid but no significant leak in inlet pipe
- replaced the Nozzle Servo with new one
- checked the Nitrogen Accumulator the pressure was 350 PSI and increased it to 800 PSI
- full calibrate the NGV Servo and LVDTs
Do you have any idea what possible causing this issue?
Note: the turbine now online and loaded, LP speed at 98%
Machine : GE MS5002C
Control system: Mark VIe TMR
we just completed Zero overhaul
Indications
1- Control oil pressure drop to 58 PSI
2- Nozzle current suicide @ 2.5 degree if we increase the LP speed fast
Observation:
- during start up the control oil pressure stay at 110 PSI.
- at LP speed 95%, auxiliary pump stopped and pressure dropped to 90%
- Control oil pressure gradually decreasing to 58 PSI within 2 hours
- Lube oil pressure steady at 150 PSI
- Hydraulic pressure steady at 1220 PSI
- during calibration the nozzle acting perfect and no deviation between the Ref and position feedback
- during the startup the current suicide happened and gap between Ref and feedback exist and the LP speed go back to 70%
- we should increase the LP speed slowly to avoid current suicide
Action taken so far:
- checked and replaced the Lube oil filters
- replaced the hydraulic filters and hydraulic GCV filter
- checked the Dump solenoid but no significant leak in inlet pipe
- replaced the Nozzle Servo with new one
- checked the Nitrogen Accumulator the pressure was 350 PSI and increased it to 800 PSI
- full calibrate the NGV Servo and LVDTs
Do you have any idea what possible causing this issue?
Note: the turbine now online and loaded, LP speed at 98%