Advise needed. Diesel generator loading issues

[HomeCert ltd]

Hi everyone,

I would really appreciate some advise. I'm a domestic electrician but my neighbors asked me for some help on a issue he has and here I am.

So my neighbor has a tree surgeon company, they have a yard where the cut and dry logs as well. So they've just got a new drying system installed and have a new 20KVA generator to power the yard. A few weeks ago the generator started spewing oil, the manufactures said it's because the generator is be under loaded, so they said they should ideally run the generator at 12KVA to be most efficient.

I went to the yard today and the supply is 3-phase. I measure the current drawn on each phases as L1:4.4amps - L2:0.4amps - L3-1.0amps

Total loading 5.8amps. If I put this into KVA I get 4.0KVA on 230v and 5.8KVA on 400v.

I worked out 12KVA to be around 17.3amps

Any if the above i correct or am I completely wrong somewhere. Also any advise on the best way to increase the loading, the yard is ran 24/7 and is in constant us. I was thinking of a dummy load, but wanted to get other opinions or ideas! I've attached a pic or 2 of the generator and controls.

Any advise is welcome.

 

[PEG]

Hi,i know the Perkins 404D engines,fitted to these,and if it is "spewing oil",it will not be your customers use...it has other issues.

They are a relatively small,non-turbo engine,and,are not under loaded,as such.but are stretched,at maximum output.

I have seen many identical engines with hideous hours clocked,which do not jetison the black stuff. There are many reasons for the oil expulsion,and this wants diagnosing first.

Blocked breathers,failed gaskets/seals,fractures,wrong oil,worn bores due to air filter issues,running hotter due to radiator clogging and degrading the oil,and a few more besides.

Bore glazing and similar problems occur more frequently in larger engines,with larger,slower swept mass components,such as the bigger Cat engines. An old and far from HS at W approach,was to run these engines up to half max rpm,and drop a glass petri-dish in the open inlet tract....this allegedly got them bores back to cross-hatch

I could show you a very old Gen-set 17 kVa unit,which has been on me pals yard for nearly twenty years,in daily use,minor lighting 99% of the time,occasional hand tools. Similar 4 cyl n/a engine,and that goes through nothing but diesel.

 

[dmxtothemax]

I'am no diesel mechanic
but even I know running a 20kva genny
for long periods on a small load like that is problematic
you should consider either solar & batteries for night
And run the BIG genny during the day only.
Or have a smaller say 2kva for night.

 

[bailes1992]

Do we know if these generator engines are run-in in the factory or is there a strict run-in procedure that has been neglected?

I've seen plenty of well broken in generators run nothing but light loads for years on end and they don't use a drop of oil!

If it's bore glazing I would recommend finding a monograde SAE30 oil and running the engine with high but continuously changing loads for several hours.

 

[elsparko]

did the first electrician just so happen to have a 20kva generator for sale by any chance?

 

[Lucien Nunes]

Thanks PEG, some good insight there. I don't know the unit, and stand corrected on its light load endurance.