# modifying 3 phase generators ?



## Tirediron (Jul 12, 2010)

I have several 100 + kva generator heads, 1800 rpm, is there an economical way to convert the out put to DC to feed battery banks. Or is it possible to pull power off of the legs to get 60 cycles at a lower speed ?? 
selling them and buying smaller gens is not an answer that I am looking for.


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## Coastal (Jun 27, 2013)

I've converted one from 3 phase to single phase....not to DC though. Get 200 battery chargers from Canadian Tire?


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## LincTex (Apr 1, 2011)

Yes - - To all of it. 
Well, sort of....

To get DC you will need rectifiers (diodes), there is no way around that. Then you have the freedom to spin them at whatever RPM you want as long as it's within range (and you can adjust field strength). 

You would still need to run your DC output through some sort of charge controller, PWM preferred.

To get AC at 60Hz - yes, it is possible as long as the windings make that feasible. 12 leads reconnectable, yes? Delta and Y possible? What form of voltage regulation is available?


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## LincTex (Apr 1, 2011)

What R you gonna be spinnin' them with?


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## LincTex (Apr 1, 2011)

http://www.smokstak.com/forum/showthread.php?t=47678

http://www.smokstak.com/forum/showthread.php?t=111718

http://www.smokstak.com/forum/showthread.php?t=23666

http://www.smokstak.com/forum/showthread.php?t=21178


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## Tirediron (Jul 12, 2010)

I have several 3306 PCT cats, not real fuel efficient at 1800, unless you use the load, I want to run one at 900, preferably on waste oil, I will try to figure the winding sequence out and post it later


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## LincTex (Apr 1, 2011)

Tirediron said:


> I want to run one at 900, preferably on waste oil,


No, you will "wet-stack" way too bad. Those Cats hate low RPM work.


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## LincTex (Apr 1, 2011)

http://www.thedieselgarage.com/forums/showthread.php?t=69819



> Cat hasn't had pre-cups since before there were emission laws.


That kills your plans for waste oil use, right there. The only good successes I have seen with waste oil were ALL "pre-combustion chamber" type injection engines, NOT direct injection. My Cummins is direct and really, it hates anything over 10%-15% used oil.


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## LincTex (Apr 1, 2011)

I know the heads are 100kva, but how many watts are you REALLY tring to generate?

Engines that do well with used oil are older early 80-early 90's Ford V8's (International Harvester/Navistar) and two-stroke Detroit Diesels (which will supposedly run on straight waste oil with some pre-heating of the fuel)


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## Tirediron (Jul 12, 2010)

they are industrial pre-cup engines, if I advance the Cam about 2 teeth, and put a tiny snail on the compressor side, I think It should work, the stroke/ bore on a 3306 is pretty high, And they bolt right to the gens, I would like to be able to pull about 15 KVA peak per phase, assuming I can draw off of all three, but the load would be a lot lower most of the time, maybe 5 KVA per phase, all said it may be easier to just gear the gens so the head runs 1800, and just wire it up normal. With gearing I could run the cat at 1200,


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## LincTex (Apr 1, 2011)

if you start swapping turbo housings, make sure you build a balanced unit - if you change to a smaller compressor, then you will never spool up because your turbine housing is too large. At that point, it's best to just get an entire turbo from a smaller engine. 

Ages ago, I saw an old farmer had built his three phase gen from a V8 555 Cummins and ran the gen through a truck transmission. He had already passed, so I don't know what the reason for it was - maybe what you are trying to do here.

45Kva at 1200 rpms... hmmmm, that might be doable. For gearing, I would use a large multi-V belt drive, like 2 or 3 10-rib belts with pulleys around 9" and 12" in diameter. Very expensive (you could also use multi 6-rib automotive belts, but a lot more! 6-7?). Using a truck transmission would destroy efficiency, you may as well just run at 1800 RPM because the fuel burn rate would be the same.


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## Tirediron (Jul 12, 2010)

just using them as they are keeps coming up as the simple answer, I guess the next test is to check the actual fuel consumption at lower loads, maybe it will be acceptable, the 555 probably needed to be geared down to get it into the power range??, now there is a slobbering engine. If listeroids weren't so damn expensive, I would just belt drive my shop tools.


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