Detroit 2-71 diesel

[XS650]

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Originally posted by Audity:

I'd be interested to check the output with a frequency meter to see how close it is to 60 hertz. Computers run fine on its power. It's right at 120v.

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Get a 220V light bulb or hook 2 110v bulbs in series. Hook one lead to you generator, and the other lead to you power company 110V. The lights will get bright and dim at generator frequency minus power company frequency.

That alone won't tell you whether you generator is fast or slow, just the magnitude of the differance in frequency.

 

[LarryL]

That series of diesel has to be the toughest engine in the world, and easy to work on. We had a 2-71 generator in the shop and an 8V-71TA engine in a converted Greyhound bus. There was nothing you could do to break either engine. And, funny, they only liked 40wt oil, Delo 400. We tried multigrade and even synthetic and nothing worked like plain old Delo 400 40wt. And both engines worked best when worked hard. On the bus engine, I liked how you could move engine accesories around to different mounting points with very little trouble. You can tell that these engines were designed by people that worked on them.

 

[Shannow]

quote:

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Originally posted by XS650:
Get a 220V light bulb or hook 2 110v bulbs in series. Hook one lead to you generator, and the other lead to you power company 110V. The lights will get bright and dim at generator frequency minus power company frequency.

That alone won't tell you whether you generator is fast or slow, just the magnitude of the differance in frequency.

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Given the generator connection requirements down here, that would be an illegal connection, and a big fine.

Would it actually work ?

You're sorta looking for a "beat" frequency.

Wouldn't the Diesel synchronise with the grid ?

OTOH, I may be a power station "sprocket head", who sees what happens when hard wired 300 tonne rotating masses get synchonised without synchronicity.

(BTW, one of the stations in Oz had the generator circuit breaker closed accidentally with a stationary shaft...350MW DOL start)

 

[tdi-rick]

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(BTW, one of the stations in Oz had the generator circuit breaker closed accidentally with a stationary shaft...350MW DOL start)

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whoa, any hints on where ??

 

[Jim Allen]

I worked on a bunch of 71 series engines (3-71, 4-71 and 6-71 mostly) back in my Army Sailor days, as well as 6-110s. Real brutes, all of them. Reliable as gravity most times, though I did see a couple that ran away. Some vessels used a hydraulic starter that eliminated all the electrical mess. You used a hand pump to charge an accumulator and that pressure operated a hydraulic starter motor. That was 35 years ago. If not available today, a setup like that could be built, I'm sure.

 

[Ken2]

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they only liked 40wt oil, Delo 400.

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Old Delo 400 straight 30 or 40 was OK in two stroke diesels. Modern Delo 400 isn't...Delo 100 is the right oil for these engines now.

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Wouldn't the Diesel synchronise with the grid ?

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IF you had the right instruments to match it to the grid, yes. It still must have a suitable governor to keep from either giving all the load to the grid and becoming motorized, or taking all the load until it trips.

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You used a hand pump to charge an accumulator and that pressure operated a hydraulic starter motor.

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Still available and used on ship's emergency diesel generators and lifeboat engines.


Ken

 

[Audity]

Interesting idea to check for a beat frequency using light bulbs. I'll give it a try with two 120v bulbs in series.

This unit has a strictly mechanical governor for controlling rpm and a straight-through drive to the generator. I haven't looked at how to adjust the governor yet.

Operating speed is quoted as 1200rpm, so it appears that frequency = rpm/20, or 3 cycles per revolution. I wonder if these were sold into 50-cycle applications with only a change to the governor, to run at 1000 rpm?

Syncronization is not an issue, it only operates in an island mode. There is no facility to interconnect and run parallel, just a big grid/off/generator transfer switch.

Just read the above, I'm showing my age by using cps rather than hz. Never got used to that terminology change, cycles-per-whatever is much more descriptive.

 

[416Rigby]

They use a 6-pole gen head that produces 60Hz at 1200rpm.