Maintaining the diesel generator?

softdown

So I figure that engines should be ran a couple times/year for several reasons. Yet I seem to recall that running diesel generators without a load is "hard" on the generator. If so, what would be a happy medium? 

The guy who installed my solar was pretty smart so I only need to run the generator about once/year. That is usually because a battery gave up on living.

I figure that running the generator for ~fifteen minutes...every ~six months...helps keep things working properly. Fifteen minutes of no load run time is not a very long time. 

mike95490

In the off season,spring/summer/fall I run each genset about 15-20 min, keeps the oil in the bushings, helps dry out water and prevent injectors and fuel pump from sticking.  I usually do it in the morning and charge batteries as a load.   Modern diesels since 2005 or so, have pretty tight tolorances and run higher RPM's than earlier diesels, and are more resistant to "Wet Stacking" problems.

https://powercontinuity.co.uk/knowledge-base/what-is-wet-stacking/   &    https://en.wikipedia.org/wiki/Wet_stacking

mcgivor

In commercial applications a standby generator is generally run once per month for at least an hour on house loads and all fluid levels including start battery are checked, an annual full load test is conducted with a load bank and oIl changed. The schedule may vary, but the but the tests ensure that the backup system is available when and if needed. The genset needs to run at least long enough to reach operating temperature, in order to ensure all components are working as designed, records are kept to reveal any changes in temperatures, load, voltage, frequency etc. etc. which would reveal a potential problem before it becomes a major issue. Running without load is not recommended because working temperature will probably not be reached which is needed not only to prevent wet stacking, but also to vaporize condensation which can accumulate inside the engine, especially in cold climates without block heating. Another benefit of regular testing is that fuel is burned, which needs to be replaced periodically due to bacterial growth. Using a load bank such as space heaters is useful to conduct testing and allows the generator to actually work as opposed to run. The importance of conducting these tests are in direct proportion to how critical  the backup power is to the application and the value placed on the equipment. Personally I run once a week at ~50% load pumping water for at least an hour, checking oil level, voltage, frequency and all other relevant items, such as connections loose fittings etcetera.