# Old school military generator



## fdew

That is GREAT. I like those old 4 cyl generators. If you ever need info on it, here is a link.

http://www.smokstak.com/forum/forumdisplay.php?f=6

Consider bringing it to a local old engine show. 

Frank


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## HARRY304E

That's a beauty .:thumbup:


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## stuiec

View attachment 32531


I love this old stuff. So elegantly clean and un-cluttered. _ Very _cool. :thumbsup:


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## 8V71

fdew said:


> That is GREAT. I like those old 4 cyl generators. If you ever need info on it, here is a link.
> 
> http://www.smokstak.com/forum/forumdisplay.php?f=6
> 
> Consider bringing it to a local old engine show.
> 
> Frank


Thanks, I was really drawn to the engine when I first saw it. Later found out that it's a Contenential Red Seal. I can get the idle so slow that you can count the fan revolutions and the magneto clutch will click in.

It's actually a backup generator for a generator so even though it was made in 1961 it never saw much use. Mechanically it's like new but the outside is beat to crap. I spent a lot of hours hammering on panels so everything would close up properly but didn't have to do much on the inside.


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## 8V71

HARRY304E said:


> That's a beauty .:thumbup:


I'm a pushover for this kind of stuff. It's going to be my backup generator when I get a house built. This engine was used a lot in forklifts and easily converted to propane which I may do.


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## Big John

That's awesome, I bet that thing is an absolute work-horse. Now all you need is to drum-switch the stator leads so you can automatically change your voltage and phase-configurations. 

You come by it at an auction?


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## 8V71

stuiec said:


> View attachment 32531
> 
> 
> I love this old stuff. So elegantly clean and un-cluttered. _Very _cool. :thumbsup:


Yep, it's rare to see this nice craftmanship these days. That shorting busbar is how you set the generator up for the differents outputs. You can see the unused bars bottom center of the control panel picture in my first post. They are clamped down to a cover.


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## Vintage Sounds

Wow that's awesome. Where did you get it?


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## HARRY304E

8V71 said:


> I'm a pushover for this kind of stuff. It's going to be my backup generator when I get a house built. This engine was used a lot in forklifts and easily converted to propane which I may do.


Love it,I wish I had a camera with me in the old days .:thumbsup:


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## 8V71

Big John said:


> That's awesome, I bet that thing is an absolute work-horse. Now all you need is to drum-switch the stator leads so you can automatically change your voltage and phase-configurations.
> 
> You come by it at an auction?


Oh sorry, see my response to stuiec. Craigslist purchase. The last thing I did before offering money was look in the radiator cap. My heart sank when I saw a thick film of oil floating on top. So I bought it at a much reduced price knowing almost 100% that it had a cracked block or some sort of serious problem. Come to find out that the military puts that crap in the coolant systems to prevent corrosion so all was well.

It was not running either because the guy threw out the nice stainless plug wires and replaced them with standard rubber ones. They were just shoved into the magneto but they were a larger diameter and not going all the way in to the contacts in the bottom. The whole time he was telling me the generator just had a fuel filter problem. :blink:


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## 8V71

Vintage Sounds said:


> Wow that's awesome. Where did you get it?


Thanks....I found it on Craigslist.


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## 8V71

Big John said:


> That's awesome, I bet that thing is an absolute work-horse. Now all you need is to drum-switch the stator leads so you can automatically change your voltage and phase-configurations.
> 
> You come by it at an auction?


I wonder how this, possibly derated for the military, 12.5kw continuous duty generator compares to present day generators? Is the advertised power of home generators continuous duty? A drum switch would be nice but the shorting bars make it pretty easy to change around in a pinch. It also has an impressive amount of filtering on the generator output.

Here is a pic of another same model generator to give an idea of the size.


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## fdew

8V71 said:


> I wonder how this, possibly derated for the military, 12.5kw continuous duty generator compares to present day generators? Is the advertised power of home generators continuous duty? A drum switch would be nice but the shorting bars make it pretty easy to change around in a pinch. It also has an impressive amount of filtering on the generator output.


I have a 1947 Kohler that I take to engine shows. and a 1960 something Onan The differences between these and a modern big box store are amazing. First the old generators ran at 1800 RPM not 3600
Second the old ones had a 4 cylinder engine (The onan is 2 cyl)

My Kohler has a 4 cyl engine and develops about 3 hp (1200 watts) It contains 9 qts of oil, is water cooled. It was designed to serve as the only power source for a home or farm (Not a backup) and appears to have been designed for a service life of forever.

AND it is automatic start (senses a load and starts, remove the load and it stops.)

http://www.oldengine.org/members/frank/kohler1.htm


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## TOOL_5150

OK, the Y is Wye, the triangle is Delta.... what is Z?


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## 8V71

fdew said:


> I have a 1947 Kohler that I take to engine shows. and a 1960 something Onan The differences between these and a modern big box store are amazing. First the old generators ran at 1800 RPM not 3600
> Second the old ones had a 4 cylinder engine (The onan is 2 cyl)
> 
> My Kohler has a 4 cyl engine and develops about 3 hp (1200 watts) It contains 9 qts of oil, is water cooled. It was designed to serve as the only power source for a home or farm (Not a backup) and appears to have been designed for a service life of forever.
> 
> AND it is automatic start (senses a load and starts, remove the load and it stops.)
> 
> http://www.oldengine.org/members/frank/kohler1.htm


Wow....neat stuff! I go to a local show every year and really enjoy it.

I wasn't clear but I was mainly wondering about the duty cycle of larger permanent generators for home backup, Generac's etc.... Just curious if mine would handle about 15 or 17kw intermittant.

I can't remember the engine model, maybe F168? But it's the largest F with IIRC ~30-35 hp.


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## 8V71

TOOL_5150 said:


> OK, the Y is Wye, the triangle is Delta.... what is Z?


That's a new one for me too. :001_unsure:


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## Wirenuting

8V71 said:


> That's a new one for me too. :001_unsure:


I think its a 55/55 setup. 
Good for amphibious operations and field use. 
Don't quote me, it's been to many years since I saw that.


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## just the cowboy

I had a friend that bought one like that, ONLY problem with it was it was 400hz. 
He thought he got a good deal.


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## Awg-Dawg

TOOL_5150 said:


> OK, the Y is Wye, the triangle is Delta.... what is Z?


 
I think this is it.


http://www.electriciantalk.com/f2/generator-double-delta-1370/


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## 8V71

Awg-Dawg said:


> I think this is it.
> 
> 
> http://www.electriciantalk.com/f2/generator-double-delta-1370/


Thanks for that link. I'm trying to match up my schematic to a zig zag but I'm only finding 12 wire examples and I have a 6 wire. Maybe it's just a zig or a zag but not both? :laughing:


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## Awg-Dawg

8V71 said:


> Thanks for that link. I'm trying to match up my schematic to a zig zag but I'm only finding 12 wire examples and I have a 6 wire. Maybe it's just a zig or a zag but not both? :laughing:


Theres a lot of sharp guys on here, Im sure one of them can help you out.


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## 8V71

OK, it works out to the top diagram but without parallel windings.


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## 8V71

8V71 said:


> OK, it works out to the top diagram but without parallel windings.


I don't understand how this works. It is saying 120 volts between each line and neutral but it seems lopsided to me.


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## 64pvolvo1800

8V71 said:


> I don't understand how this works. It is saying 120 volts between each line and neutral but it seems lopsided to me.


Almost like buck boost on the one side, commonly called dogleg or zigzag.


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## 8V71

64pvolvo1800 said:


> Almost like buck boost on the one side, commonly called dogleg or zigzag.


That's where I'm getting lost. So that means the voltages are not the same in all 3 phases?


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## Meadow

Z=

Configuring a 3 phase for single phase generation, and yes, you do get 120/240. 

To this day almost all 100kw and below gen sets can be configured for single phase if 3 phase to start.


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## 8V71

64pvolvo1800 said:


> Almost like buck boost on the one side, commonly called dogleg or zigzag.





meadow said:


> Z=
> 
> Configuring a 3 phase for single phase generation, and yes, you do get 120/240.
> 
> To this day almost all 100kw and below gen sets can be configured for single phase if 3 phase to start.


I'm weak on 3 phase stuff but I think I see what's happening now....thanks! (phase angle)


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## gnuuser

my father has on and i think the engine was made by kohler but im not sure


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## 64pvolvo1800

8V71 said:


> I'm weak on 3 phase stuff but I think I see what's happening now....thanks! (phase angle)


This is true but caution taken, they can be 2/3 or even 1/2 the three phase rating depending on the winding meat. Usually you can do either double delta or zigzag for single phase. I prefer dd myself.


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## 8V71

64pvolvo1800 said:


> This is true but caution taken, they can be 2/3 or even 1/2 the three phase rating depending on the winding meat. Usually you can do either double delta or zigzag for single phase. I prefer dd myself.


I think this means 52 amps at 120 which follows what you are saying. But is there another 52 amps availiable between neutral and the other hot leg or just 52 amps total?


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## Big John

I don't know much about generator zig-zags, but my temptation is to say 52A total.

If you look at the Y and Δ setups, the current maxes out at 34.7A per winding.

The zig-zag looks like it works by taking the winding at the base of the delta and using that single winding to get 120V-N. The remaining two windings give you the other 120V-N (just like a normal open-delta would). And across the single winding and the end of the open-delta you end up with 240V (just like with two windings of a closed delta).

But I'm having trouble figuring out where the 52A comes from. It's like one winding gives the full 34.7A and another just half of that. And I can't figure out why.


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## 8V71

Big John said:


> I don't know much about generator zig-zags, but my temptation is to say 52A total.
> 
> If you look at the Y and Δ setups, the current maxes out at 34.7A per winding.
> 
> The zig-zag looks like it works by taking the winding at the base of the delta and using that single winding to get 120V-N. The remaining two windings give you the other 120V-N (just like a normal open-delta would). And across the single winding and the end of the open-delta you end up with 240V (just like with two windings of a closed delta).
> 
> But I'm having trouble figuring out where the 52A comes from. It's like one winding gives the full 34.7A and another just half of that. And I can't figure out why.


Well John, thanks for looking. I never questioned any of this until Tool_5150 asked what a Z was and it motivated me to search the net. For the Z configuration there is of course L1, L2, and neutral, so is one side stronger than the other? does the neutral current cancel if balanced? This is way over my head at this point, and it might be a non-issue with the actual 120 volt loads it may see in the future.


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## Big John

> ...This is way over my head at this point, and it might be a non-issue with the actual 120 volt loads it may see in the future.


 I hear ya, I just like to understand how things work. I'll see if I can find clear answers to your questions, because I'd be straight guessing at this point.


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## 8V71

Here is a cool (but worthless to me) feature that I would like to mention. The generator has a built in gasoline fueled heater to help it start and immediately come up to speed in cold weather. This was confusing to me at first because the blower draws a good bit of current from the batteries and it might run them down in cold weather and then the generator wouldn’t crank. This is how I found out that this model is a backup generator for another running generator. There is an umbilical cord running between this generator and the running one feeding it 24 volts to operate the heater and keep a charge on the batteries.

Engine coolant flows into a coil of tubing inside of the heater that circulates it through the rest of the engine by thermal convection. The heater exhaust is piped into a box on the bottom of the oil pan and then to a gap between a double wall battery box where it eventually exits out of a hole. It’s scary sounding, like an oil furnace burner, but it runs pretty clean.

I didn’t take any pictures of the heater but here is one I found on the web. It sits behind a cover right below the electrical control panel.


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## MTW

My attempt at a bobelectric posting:


Sqr root of 3.


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## 8V71

MTW said:


> My attempt at a bobelectric posting:
> 
> 
> Sqr root of 3.


Right back at ya!


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## MTW

8V71 said:


> Right back at ya!


:thumbup::laughing:


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## 64pvolvo1800

8V71 said:


> I think this means 52 amps at 120 which follows what you are saying. But is there another 52 amps availiable between neutral and the other hot leg or just 52 amps total?


52 per leg of 120. Do the math and you'll see 6kw per leg (52a x 120v = ~6,000watts) 
Ideally, if you only have 120v loads, you want to balance them.


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## millelec

this is an interesting surplus site. you do have to watch out for the 400 hz gens, as there are a lot of them offered there as well. 

http://www.govliquidation.com/

I like the 6x6 trucks, they offer one that has a mini-machine shop in back.

http://olive-drab.com/idphoto/id_photos_m944.php


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## RICK BOYD

*416v 3 phase ???*

a friend of mine has a military 60 kw powered by an Allis Chalmers
and it puts out every voltage , hertz & phase I ever heard of 
plus ( 416v 3 phase) ?



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## 8V71

64pvolvo1800 said:


> 52 per leg of 120. Do the math and you'll see 6kw per leg (52a x 120v = ~6,000watts)
> Ideally, if you only have 120v loads, you want to balance them.


Good deal....thanks. :thumbsup:


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## 8V71

millelec said:


> this is an interesting surplus site. you do have to watch out for the 400 hz gens, as there are a lot of them offered there as well.
> 
> http://www.govliquidation.com/
> 
> I like the 6x6 trucks, they offer one that has a mini-machine shop in back.
> 
> http://olive-drab.com/idphoto/id_photos_m944.php


I signed up with them a few years back and bid on a sweet diesel genny mounted on a trailer with canopy. I work just a few miles from Fort Meade and took a look at it before I bid. The generator was pristine and it went higher then my bid.

An internet friend that has this same model gasoline generator is a military buff and he has a 6x6 truck. He started out with an older olive drab one, sold it, and a few months ago got a newer model with the desert storm colors. It amazes me how much machinery one can buy for relatively little money. He got both trucks from the site that you mentioned.


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## 8V71

RICK BOYD said:


> a friend of mine has a military 60 kw powered by an Allis Chalmers
> and it puts out every voltage , hertz & phase I ever heard of
> plus ( 416v 3 phase) ?


It looks like you could run that anywhere in the world.


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## Big John

So I ran it by one of our winding guys and he agrees with _64pvolvo, _52A per winding.

If you do the math on that though, it means you have a generator stator with almost 19kVA capacity, so my question was why you ended up with 34.5A per winding in a Y?

He thinks it's because of the size of the prime-mover or the limits of the excitation (which you can see peaks out at 22A in a zig-zag configurations), so that you only have 12.5kW of power available to drive the generator, and in a 208Y that necessarily knocks your current down to 34.5A.


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## 8V71

Big John said:


> So I ran it by one of our winding guys and he agrees with _64pvolvo, _52A per winding.
> 
> If you do the math on that though, it means you have a generator stator with almost 19kVA capacity, so my question was why you ended up with 34.5A per winding in a Y?
> 
> He thinks it's because of the size of the prime-mover or the limits of the excitation (which you can see peaks out at 22A in a zig-zag configurations), so that you only have 12.5kW of power available to drive the generator, and in a 208Y that necessarily knocks your current down to 34.5A.


Thanks John, I really appreciate that. :thumbsup: Is the 19kva figure coming from a calc. on the 3 phase?

P.S Leaving work now.


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## Big John

8V71 said:


> Thanks John, I really appreciate that. :thumbsup: Is the 19kva figure coming from a calc. on the 3 phase?


 Yes, because if each winding is capable of carrying 52A and you connect them in a 208Y you get 52A*1.732*208V=18,733VA


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