Ratchet Problem in GE Frame-VIB Gas Turbine


Thread Starter

Sukhdev Singh

Dear Friends,

The ratchet problem observed in one of our GE frame-VIB gas turbine few days back is the 33HR switch toggle to state "1" immediately at start of ratchet cycle. Normally it should pick up at the end of forward cycle approx after 12 seconds start of the normal ratchet cycle. But due to early pick up of 33HR within 2 seconds of the L20CSX and L4HR, the ratchet cycle terminates premature.

Please inform possible solution to the above mentioned problem.

Sukhdev Singh,

The likely cause is either dirty filters in the hydraulic ratchet system, or dirty oil and problems with the hydraulic ratchet self-sequencer mechanism. Either can cause the plunger for 33HR to operate prematurely as you have described.

The first is relatively easy to solve; the second may require the replacement of the self-sequencer. However, either problem may be indicative of a more severe underlying problem: inadequate maintenance of lubricating oil.

Please write back to let us know what you find and how you resolve the problem.
i am sending you some check point .kindly workout on this check point and let me know.

(1) 20cs is pick up properly or not from giving the command from hmi (400-500) ohm should come on coil

(2) Clean Filter, installed after 88HR (Ratchet Motor.

(3) OverRun Clutch Should Be Move Only Anti-clockwise (IMP. Point)

(4) Clean Self Sequencer With Clean Diesel

(5) Limit Switch (33cs) Should Be mounted as per device means:Torque converter clutch 75% engaged with shaft and close feedback should come on hmi (IMP Point). Kindly check the mounting of limit switch.

Workout on above points and let me know if you have any doubts.

Anand Kumar
Steag Energy Services (Bathinda)

Sukhdev Singh

Thanks for your valuable suggestions. I shall check the system as per your suggestions and update the findings. At present unit is running and have plan for HGPI shutdown within one month, I will do all the checkings during that period.

Thanks & Regards,