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Old 04-25-16, 06:00 PM   #28
Robaroni
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You're matching your load more closely with the lower speed but a smaller generator regardless of frequency would have saved you more.

The reason your African generator used more fuel at 60HZ was because it had to run higher speeds to reach the frequency, not the power. Again, if you only needed 15KW you could have used a smaller generator that matched the load closer regardless of frequency. A 20KW generator running at 60 Hz would have used less fuel than your 50KW generator at 50Hz. Your generator was above the power your needed at night regardless of the frequency so running at the lower speed saved fuel.
There is a point of diminishing returns, running a 60Hz generator at no load uses less fuel than a 50Hz generator running a load. If you needed 50KW during the day and you could get it with 50 or 60HZ you would have realized very little if any saving. It depends on the range your engine gets its best efficiency at, if that's the higher rpm than during the day 60Hz would yield better fuel savings.
Power out equals power in minus efficiency losses.

What is the highest power you'll need? That's basically the generator you want. Don't worry about frequency, power needs are the important factor.
Rob
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