Hello Friends,

My plant has been having issues of ratchet trouble on one of our turbines(GE Nuovo Pignone MS5001 Frame V).
This issue started when the unit tripped,it was later observed that it could not ratchet,the cause was channeled to the overrunning clutch as the torque converter jaw clutch could not turn.Damaged overrunning clutch was changed and unit ratcheting sequence was ok and turbine started.
It was observed that on consequent turbine trips,unit could not ratchet unless damaged overrunning was changed,which was not a good operation and we decided to change the torque converter as our root cause analysis boiled down to it.
Torque converter successfully installed and ratcheting sequence was fine for about four months,then the initial problem surfaced again.
Please guys what could be the root cause and the possible solution to end this miserable mode of operation.
Thank you.

 

Hello Friends,

My plant has been having issues of ratchet trouble on one of our turbines(GE Nuovo Pignone MS5001 Frame V).
This issue started when the unit tripped,it was later observed that it could not ratchet,the cause was channeled to the overrunning clutch as the torque converter jaw clutch could not turn.Damaged overrunning clutch was changed and unit ratcheting sequence was ok and turbine started.
It was observed that on consequent turbine trips,unit could not ratchet unless damaged overrunning was changed,which was not a good operation and we decided to change the torque converter as our root cause analysis boiled down to it.
Torque converter successfully installed and ratcheting sequence was fine for about four months,then the initial problem surfaced again.
Please guys what could be the root cause and the possible solution to end this miserable mode of operation.
Thank you.

Hi All,
Ebuxtech,

Did you have a search on this forum a thread that can enghlight you on your troubleshooting???

Here is one of them:
https://control.com/forums/threads/frame-5-gt-problem-with-ratchet-diesel-engine-overshoot.45129/

There are many of good threads discussing the issue with Ratchet/torque converter on frame V on this excellent forum, I suggest you to keep on searching till you get some valuables datas for resolving this issue.

Also if you can developp more on the issue you have facing, we can try to give you support !

Controls Guy25

 

Can you explain what you mean by "overruning clutch as the torque converter could not turn" particularly overrunning clutch

 

What i meant was that we had a damaged overrunning clutch as a result the starting means jaw clutch could not rotate and engage the turbine.

 

Lets try again, I know what a jaw clutch is and a torque converter and I know exactly how they work but what is an overrunning clutch?? Do mean the clutch tried to engage when the shaft was turning or what??

 

Hi All,
Ebuxtech,

Did you have a search on this forum a thread that can enghlight you on your troubleshooting???

Here is one of them:
https://control.com/forums/threads/frame-5-gt-problem-with-ratchet-diesel-engine-overshoot.45129/

There are many of good threads discussing the issue with Ratchet/torque converter on frame V on this excellent forum, I suggest you to keep on searching till you get some valuables datas for resolving this issue.

Also if you can developp more on the issue you have facing, we can try to give you support !

Controls Guy25

Thanks i already searched but was not the same issue we are expreiencing.

 

Lets try again, I know what a jaw clutch is and a torque converter and I know exactly how they work but what is an overrunning clutch?? Do mean the clutch tried to engage when the shaft was turning or what??
[/QUOTE]

Ok Glenmorangie i dont know the term you use to identify it but we call it overrunning clutchover here.
Overrunning clutches,often known as freewheel clutches are used to freewheel in one direction while driving in another direction of rotation. When the driven shaft is rotating faster than the driveshaft, the clutch mechanically disconnects the driveshaft from the driven shaft.They offer greater torque but are limited by their bore size due to radial space restrictions.
Attached is a picture of it.

 

Thanks for that, it is a Sprag Clutch, usually part of the Torque converter. You said these were Nuovo Pignone Frame 5 machines, do you know when they were manufactured? You said these machines were from Nuovo Pignone, are these clutches from the original build? What is the starting means, diesel, electric or what?

 

Just found the attached file on the Net, now I understand what we are talking about. Can you give the part no. for your Torque Converter

 

Just found the attached file on the Net, now I understand what we are talking about. Can you give the part no. for your Torque Converter

Thanks a lot for the pdf file Glenmorangie,it's really insightful.
I will check for the torque converter part no,hopefully i will get it and give you a feedback.
Thanks Sir once again.

 

I asked some other questions on my last Emails, can you try to answer so I can move forward

 

I asked some other questions on my last Emails, can you try to answer so I can move forward

Dear Sir
Sorry for delay in reply to your last mail,find below the required answers to your questions.

1.You said these were Nuovo Pignone Frame 5 machines, do you know when they were manufactured? I think it's year of manufacture is around 1962-1970.
2.You said these machines were from Nuovo Pignone, are these clutches from the original build?No Sir,the original clutches has been damaged.
3.What is the starting means, diesel, electric or what? The starting means is diesel Engine(Detroit diesel series V71).
4.Can you give the part no. for your Torque Converter?
Torque converter Details:
Name: Voith
Type: E 7 WAT
Serial No: 8 200 879
Year built: 2006
p1: 463 kw
n1: 2100 RPM
Code no: 42120

 

Thanks for the answers. Where are you located, have you tried talking to Voith ? There is not a lot of Gas Turbine industry history on these torque converters, even myself have only seen a few in my 50 years of Gas Turbines. Let me ask around a bit, do you have any pictures of the damage and any more running information when these failures happen. What was causing the turbine trips when the damage happened?

 

These torque converters were built in 2016, since they were installed can you give some history on the machine (Maintenance, problems, unusual shutdowns), when did the clutch problems start, was there anything else being done on the machine at that time?

 

Any updates

 

As it's been a week since we last talked, I guess that you have lost the push to get this resolved. I will wait a few days for a response, if not I will move you into the " no longer interested" bin.

 

As it's been a week since we last talked, I guess that you have lost the push to get this resolved. I will wait a few days for a response, if not I will move you into the " no longer interested" bin.

Dear Glenmorangie

It's unlike me not to have replied for a couple of days now,am sorry for that.I really appreciate your concern and efforts to to help resolve this issue,my plant went on emergency outage as a result the maintenance team has been really busy all this while,i have hardly looked at my laptop screen.
On the overrunning clutch issue,our troubleshooting result was that excessive hydraulic pressure(when shutdown) was the cause,so we did some adjustment to reduce(offline) the hydraulic pressure to 70bar.we are still observing as the unit is running.

Thanks.

 

That's very interesting. How was this excessive hyd. pressure being produced ? I am assuming that you have a traditional two pump hydraulic system with a mechanical main pump and an electrically driven Aux. pump (see attached drawing). Can you then explain how this excessive pressure was being produced.

 

That's very interesting. How was this excessive hyd. pressure being produced ? I am assuming that you have a traditional two pump hydraulic system with a mechanical main pump and an electrically driven Aux. pump (see attached drawing). Can you then explain how this excessive pressure was being produced.

Thanks for your pdf Glenmorangie.
Yes sir but the unit has only one hydraulic ratchet pump(33HR),main lube oil pump and DC Aux.pump.
Based on my own understanding,a hydraulic relieve valve has a maximum allowable working pressure which is equal to or greater than the nominal operating design pressure,as a result the actual set pressure of the hydraulic valve plays a vital role in the flow rate performance.
If it is set too low(at or just above the operating pressure)the spring-loaded relieve valve will lift often but if it is set too high above the maximum allowable working pressure,there will be excessive pressure in the feed line(this resulted to our problem as our set point was at 95%).