Generator Oil Leakage

Dear all,

I need help!

We have following Brush Electric Generator at our site:

Type DG185ZL
Rated Power - 26 MVA
Power Factor - 0.85
Rated Voltage (L-L)- 6600 V
Rated Current- 2295 A
Rated Frequency-50 Hz
Year of Manufacture- 2009
Number of Poles - 4
Rated Speed - 1500 rpm

Bearing data:
Renk bearing Model: EMXLO 28-335
Order no: 164/06-07

Problem:
We are facing oil leakage from both ends i.e. NDE and DE sides. The oil is seeping in the generator compartment and being circulated inside due to internal air draft to the point that we can see oil signs from the outside form the winding coolers on the top.(see pictures)

We want to know:

1- What is the impact of oil getting inside the generator compartment and being circulated inside? How can this impact the generator in the long run?

2- What can we do to eliminate this leakage? This has been happening since long and we been unable to address it. We tried using RTV to seal the area around bearings and housing but to no avail.

Looking forward to your valuable inputs.

Regards,
Mutahir Rasool
 

Attachments

Hello

That seems to be a non negligeable oil leakage...

What is Prime mover controls systems Installed...
Any alarms /trips messages related to oil leakage annunciated..

AVR type model( is that Prismic) ..how about generator temperatures measurments ( bearings )
Any abnormal temp value constated...

When this problem occured ...( any work on that bearin/generator DE/NDE)

A P&ID would be welcome for getting picture of the installation...and try to guide you..

You will may have to dismantle that bearings for better inspection...it is related to bearing as you foclise on them..

We dont know if any device not working properly or something not ok with lube oil system..

ControlsGuy25
 
Also what is this piping arrangement on the picture showing cooling exchangers...

Again without P&ID that would be difficult to get an overall picture of the installation...
 
Thanks for the response:

What is Prime mover controls systems Installed.
It is a Gas Turbine and Turbine is MS5001.

Any alarms /trips messages related to oil leakage annunciated.
No there are no alarms on Mark 6.

AVR type model( is that Prismic) ..how about generator temperatures measurments ( bearings )
Any abnormal temp value constated...
No, max temperature on bearings is 88 deg C which is well within limits. Yes, it's Prismic A10 Brushless excitation system.

When this problem occured ...( any work on that bearin/generator DE/NDE)
Standard bearing inspection done as per part of PM plan by our Maintenance team and they preemptively changed the labyrinth seals as well back in 2018 but to no avail.

A P&ID would be welcome for getting picture of the installation...and try to guide you..
I am attaching it.

You will may have to dismantle that bearings for better inspection...it is related to bearing as you foclise on them..

We don't know if any device not working properly or something not ok with lube oil system..

Regards,
MRasool
 

Attachments

Thank you for the inputs...


The P&ID shared is for Generator gearbox instrumenation ...Do you have a lube oil P&ID available...

Did the Lube oil drain system has been investigated...

According to your statements bearing temps are ok ...

Can you tell us what is that piping for ...on the picture with cooling exchangers...
 
Thank you for the inputs...


The P&ID shared is for Generator gearbox instrumenation ...Do you have a lube oil P&ID available...

Did the Lube oil drain system has been investigated...

According to your statements bearing temps are ok ...

Can you tell us what is that piping for ...on the picture with cooling exchangers...
Can you share your email? I can share there.

Is that pipe for cooling water...
Yes the cooling water is given to the exchanger.

Is there any vapor exctractor or oil mist eliminator investigation done ....
No we did not check vapor extractor.

How about ratchet system...did you inspected it..
No we did not inspect the ratchet system. But it is operated form time to time and it is OKAY. NO abnormally observed.


Regards,
MRasool
 

Attachments

What about BRG#1 AND #2. If vapor extractor having issue as mentioned by @ControlsGuy25 , all related system must have vapor accumulation. It will be evident when you open any compartment door. Their will be vapor accumulation.

as per PI&D there is Flow gauge (FG369), must be sight glass. Is the flow ok?

Is it same problem since commissioning or the problem started after?

After maintenance is there any improvement in situation or is it same before after seal replacement job?
 
As mentionned by @munna and as I advised you before is to check return /drain line piping as there are FG installed ....

...humm need to be clarified by going on site and check that ...if lube oil flow is ok at least
 
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