Cummins KTA19, RotellaT, 4-year OCI

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Stationary back-up power generator. It was exercised at no-load once per week for 30 minutes. Had to run the facility once during this OCI for an hour or two, about a year and a half before the sample. Filters are as old as the oil. Now that I'm here, we're modifying our maintenance practices on this engine. 604.5 hours on the engine at sample time. Engine is ~20 years old.

Code:
Spectroscopic (ASTM D5185)

Fe 3

Cu 11

Pb 6

Al 0

Sn 8

Ni 0

Cr 0

Ti 0

V 0

Ag 0

Si 3

B 81

Ca 2970

Mg 215

P 1245

Zn 1433

Ba 0

Mo 46

Na 0

K 0



FTIR (JOAP method)

Fuel 0

Glycol 0

Nit 6

Oxi 13

Soot 5



TAN 1.26

TBN 8.21

Water 0.010%

Vis 100C 14.1

Vis 40C 102.7

VI 139
 
I'm a bit lost here; are you saying the sample it 1.5 years old, or that's how long ago the full-call duty cycle ran?

The engine is 20 years old.
The engine has 605 hours on it.
The engine sees typical 1/2 runs per month, plus whatever emergeny call may come up.

What I cannot seem to quite get is how many hours on on this particular sample? The long term running average is 2.5 hours/month; that is nothing really at all. However, should there not be a run-call for several months, then a half-hour run per month is a tiny fraction of use.


Overall the numbers look OK. It's really hard to know the wear on a "per hour" basis as I'm not sure what this sample represents.

TBN/TAN is very strong and could easily go longer. Contamination is non-existent by any measure. Vis look fine.

My suggestion would be to install bypass filtration (if not there already), forgot OCIs by any means of chronology, and ONLY OCI when a sample would indicate (which in this case, shows a LOT of life left in it).
 
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Fuel dilution is often a problem with diesel generators, but that doesn't seem to be the case here. Your report looks very good.

If possible, try to run the engine under load more often. Do a web search for "generator wet stacking" and you will see what frequent short runs can do over a long period of time.
 
dnewton, this generator is exercised _weekly_ at no load. Hours on this run are around 105 (don't have the data in front of me). I don't like this weekly no-load exercise, yet the results do not indicate a problem.

We load-banked this machine recently, and that will now be a regular occurrence. I'd like to cut line power regularly, and make the switch and generator work running the facility. However, I don't care for how certain equipment behaves in the face of that brief outage, so I haven't chosen to take this tack yet.

For those who were thinking of the fuel, I was thinking of that, too.
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The sample on it shows good cetane, distillation curve is appropriate/reasonable, no microbes, and no water. We additize it regularly against the issues we face in this application, and our approach there seems to be working.
 
My comment was relating to the fuel having bacteria after 20 years. Ive seen an actual bloom in the bottom of my tanks after sitting for a month.. but i havent used additives to 'kill' the bacteria either.. so kudos if your additives can keep 20 year old fuel viable.
 
The tank doesn't hold 20-years-worth of fuel.
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We only carry 500 gallons max on-hand, and it ends up being partly replenished every couple years; more frequently now that we're going to load-bank it regularly.
 
Monthly loading is a good thing. Not only good for the engine, but also the gen-head itself.

Rather than dropping main-line power to simulate an outage, why not develop a secondary, inexpensive load system (not knowing the application, I can only speculate here ...) such a running a small tool shop for a day, or perhpas fire-pump motors for their monthly testing?

As for the UOA itself, 100+ hours on this shows things are fine. The current system seems to be working, despite the low loading.
 
Originally Posted By: dnewton3

Rather than dropping main-line power to simulate an outage, why not develop a secondary, inexpensive load system (not knowing the application, I can only speculate here ...) such a running a small tool shop for a day, or perhpas fire-pump motors for their monthly testing?


The fire pump would be in bypass unless its pushing water through sprinklers...
Would have almost no load.

What kind of transfer switches do you have? i'm guessing green onan ones with 4 lights in the upper corner? Considering its an onan gen. Most likely you could perform a transfer test from the ATS at minimal risk to the rest of the facility.

The cheapest load bank would be a tub of salt water (100 gallons) with adjustable steel electrodes submerged in the salt water, cable the gen to one end and it will load it up 100% unity PF. Not OSHA approved, but used outside of america.... Thats why they make resistve air cooled load banks.

Some sites do have permanent or radiator mounted load banks, very expensive.
 
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