Purchase of ex standby generator

In the U.S., the best way to do so something like this would probably be to simply run a long, 240V cable from your house to your workshop. Or, if you really did need 3-phase power, your best bet would probably be to get a large standby generator that runs on natural gas.

If you can find one that has been load-banked on a regular basis, it is a better situation than one that has just been sitting around between uses. Sitting idle is a horrible thing for an internal combustion engine, particularly if it's deisel. Also, there is a slight "memory" effect with generators that have been run at low capacity for most of their life, but that is not a big factor. If the problem is only the lack of three phase power, there are numerous effective remedies for that if you can get an adequate single phase service to the area.>

Also remember that a generator will have to run at about 1800 rpm regardless of the load, in order to maintain a 60 hertz sine wave. That means it's going to have some serious wear and tear after a year or so of continual run. A diesel will fare better on fuel with a varying load.

I'm not positive what sort of operation you are expecting, but there is a big difference between an "emergency generator" that runs intermittantly for a few hours at the most and a "prime power generator" that runs continiously. Typically the physical size of the prime power unit will be about 3-4 times that of an emergency unit for the same output rating.

Other differences are the rpm the engine runs at, which of course will determine how fast it wears out and needs overhaul. The emergency generator will require *significantly* more maintenance that a prime power unit.

Diesel engine maintenance is also affected by the load, and if the engine is run for significant periods of time with lower than the minimum load (e.g., less than 75% of rated power) the maintenance intervals will be shorter. That would appear to be a significant consideration with the type of load you describe.

An old engine will run basically forever if it gets the proper maintenance. Before you invest in the engine though, make sure you can find people to do the maintenance, and get a good estimate of what that will be.

There are other ways besides a generator if you have 1ø power close. A phase converter will make the 3rd phase if you need 3ø. There is something called a written pole motor also. Some other alternatives probably exist that would be a bit more durable and require less maintenance than a genset.

Dean