Standby Generator Maintenance

[Steve Frazier]

I oversee buildings and grounds maintenance for a local Town and we have two large standby generators. I'm going to assume the maintenance of them as I saw the bill from an outside contractor to do the work and my department can do the same for more than 75% less cost. They are powered by large John Deere 6 cylinder turbos and do a test run cycle once a week, running for about 20 minutes.

My question is how often should these units be serviced if they don't have an extended run period between servicing? Is an annual oil change frequent enough? Open to any suggestions here. Thanks

 

[John C.]

As I recall genset maintenance is based on Kilowatt hours and there is a formula for determining it. I'm sure someone on here will know about it. Since the diesels are Deere, you probably could start with a call to the local dealership.

Good Luck!

 

[95zIV]

Steve,

The first site I could find with a time was this one, said 400 hours or 6 months, what ever comes first.

http://www.powercontinuity.co.uk/generator_maintenance/diesel_generator_maintenance.htm

 

[MECHTRONIK]

Steve I often see the engine auxillary systems tend to get neglected in these stand by units as they get little use. While oil change intervals definatly need to be conducted based on months not hours you should look at the coolant condition and have it tested at 6 monthly intervals as any cooling sys corrosion will cause problems on that day when these units are needed Also the fuel system should be serviced reguluary by draining the tank condensate and watertrap and keep the fuel tank full. Air filters should be thrown and replaced every 2 years as they do break down and radiator hoses and engine belts should be replaced at the recomended time intervals

 

[watglen]

Don't forget about the bats, and i would do an extended run with a good load to test the generator as well. Never hurts to run her hard when the power is on. Work it now so you know it'll work when its needed.

Always make sure you keep the fuel supply topped up, because if a wide area power failure occurs there's no guarantee you will be able to get diesel when you need it.

All generators aren't created equal. New ones have have corrected problems with older designs, to ensure they start (excite). I would call the generator manufacturer and ask about idiosyncrasies on that model. Search for a generator forum on the web too.

Pull some covers off the generator to make sure the mice haven't started setting up shop inside. Never hurts to spread some mouse bait around the area too.

And make sure you document everything you do, noting tests, replace components, dates etc. If they ever really need it to run and it doesn't run, you name is mud.

All in all, it shouldn't take too much effort or time to keep her running great.

 

[Kgmz]

Here is a suggestion for a forum with some good generator info.

http://www.smokstak.com/

When you get there, click on forums, and then scroll down to the generator section.

I have got some good information there on some of our older generators, like how to rewire one from 3ph 480 volt to 3ph 208 volt, etc.

We have a 35kw generac with 5.7 V-8, a 50kw Onan, and a 20kw Onan at our various businesses for backup, all natural gas or propane.

 

[micbare]

I take care of the maintenance for a medical group. We have two 40 kw diesel powered standby generators. They run under load for 30 minutes every week.
I change the oil , oil filter and fuel filter once a year and the air filter every 2 years. I have had no problems what so ever. After each generator was two years old I switched from 15w40 rotella to the fully synthetic rotella.

 

[stinkycat]

Are they heated (oil & coolant) and are the batteries on a charger. Do they start at full speed? Have a automatic oil circulating pump, are they connected to automatic buss transfer system? And what is the kilowatt rating? This makes the maintenance a little different for each set up

 

[pajibson]

I take care of the maintenance for a medical group. We have two 40 kw diesel powered standby generators. They run under load for 30 minutes every week.
I change the oil , oil filter and fuel filter once a year and the air filter every 2 years. I have had no problems what so ever. After each generator was two years old I switched from 15w40 rotella to the fully synthetic rotella.

Note micbare said "run under load" Most of us will agree that sitting unused is bad for equipment Gensets no different. When we service ours (from 2k up to 30k here right now) we run them for an hour under load as part of the process. Now we only do that annually on them, & most of these gensets thats the only hour accumulation they get.

Which model gensets and JD engine? I might have manuals for them if you need them.

 

[BlazinSS934]

I work for a municipal water district and we have Gen Sets at all of our pumphouses. We run them thru the load bank under varying loads for 30 minute and then they will idle down for 10 minutes. That is done weekly on a timer. Our operators also manually throw the transfer switch and run the plant on generator power for 30 min once a month.
We also participate in energy curtailment, we will disconnect from the grid on strategic days and run on generator.
All of our gen sets are Onan/cummins the PM's are subcontracted out.

 

[save the wells]

Generally speaking once a year is probably a safe bet. If we have a customer who is in a service agreement with us we will service the unit once a year (change oil) and usually every three years or so we will change coolant in the gen when its time for the oil service. If you monitor your coolant life by testing it periodically you could probably make it go even longer but most of our customers are data centers and hospitals and such where it's better to be safe than sorry. Load banking is always a good idea. Excercise them and they will show you any issues that might pop up.

 

[old-iron-habit]

I'm not sure how your town generators are used but here is the way hospitals are regulated.
Hospital licensing for medicare receiving facilities require generators to be load banked at 100% for 4 hours every three years. This came about a number of years ago after generators failed to perform as expected in emergencies due to carbon in the turbos. The carbon came because of many test runs with no or low load. It is always a good idea to run them under a good load once a month for 30 minutes as required at hospitals also. Some facilities don't like to transfer the load but its good to test the transfer switches also. I never dealt with a JD driven generator. The bigger Cummins were the worst offenders we dealt with. After an hour under full load they ran like a fine watch again. As stated without knowing how they are used in the town your requirements might be completely different.

 

[Nige]

Steve, when you say "standby" generators do you mean the only time they really run in anger is if the power supply from your local utility company fails..?
What do they supply power to, offices, a clinic maytbe, etc, etc..?
Also, as others have asked, do they have battery chargers and coolant heaters permanently connected to permit the sets to start and go to full load within a few seconds of the mains power going out..?
How many year total operating hours per year do they clock up, including testing..?

 

[Steve Frazier]

I had been laid off from this job in Jan. 2013 but have been rehired just in to Jan. of this year. I've been so busy with snow removal I haven't had time to look at these generators since I've been back. They kick on automatically when there's a power failure through an elaborate switching system in the building. They have block heaters and trickle chargers on the batteries and go through a test cycle once a week running for 20 minutes to a half hour. They run at full throttle, I don't know if there's a load on them or not. I'm not sure what's been done with them in my absence.

One powers Town Hall and the other a building that resembles a 3 story school. There's probably about 25 hours total run time per year during test cycles plus the occasional outage, usually amounting to just a few hours at most.

 

[Nige]

What sort of engine HP/electrical power are we talking about here and approximately what % of the generator maximum design output do they run at if the mains supply fails..?
Also it would help if you could find out if the 20-minute weekly test run is a load run or not.
I keep thinking of other things as I go along - do the alternators have any type of heaters to keep them warm and drive out humidity..?

Based on what you posted above the sets are designated as standby usage and that would indicate annual maintenance as regards oil & filter changes. However there may be other requirements for quarterly and 6-monthly maintenance, especially for the electrical side and the switching and control gear.

 

[old-iron-habit]

I would bet that the block heaters are big enough that the generators are keep at operating temperature while at standby. That is pretty much the norm for auto start generators with automated transfer switches. Are these building considered essential services building for any sort of emergencies such as a command center in a potential natural disaster?

 

[profrooky]

Hey Steve:

If you get me models and ser #s for the Deeres I can get you the Deere service schedule for the engine.

 

[Steve Frazier]

I'll work on getting the specs for both the engine and generator. It's a 6 cylinder turbo unit, I'm guessing between 150 and 200hp. I'm pretty sure it's a Kato unit.

 

[bunkclimber]

probably a 6059T or 6068T John Deere, pretty common 6cyl gen drive units