3 phase generator

[trimguy]

Leroy Somer
Type LSA410L4
Model 40978/2

Is anyone familiar with this ? I just acquired one and was checking some things out. My voltage seems high, I checked it with 2 different testers, 1 said 252 volts, the other said 257 volts. All three legs read the same with each tester. Is this voltage to high ? I also believe I have a governor problem, but more on that later. Any help would be great.

[Southside]

How old of a unit is it? I had one years back that you had to dial in the voltage each time you fired it up, just a slight tweak on a knob with a needle that you could read. 

[trimguy]

Year 1992 . I don't recall seeing a knob . I will look tonight when I get home. 

[trimguy]

 

 

[sawguy21]

It sounds like your engine speed is too high,, dial it back to 1850rpm no load and check the voltage.

[trimguy]

What would be the best way to check the RPM's ? It doesn't have a tachometer on it.

[Magicman]

Is either end of the engine or generator shaft accessible?  If so there are many options available for direct contact tachometers:  LINK

There are also other options such as optical/photo or wired.

[beenthere]

Think I've heard of an rpm app for a smart phone. Giri comes to mind, but have not tried it. 

[trimguy]

A couple of pictures.

 


 
The round thing is not a knob, it's a transistor, or resistor, or something. I ordered the tachometer and the link from above, thanks @Magicman. Does anything look familiar @Southside, or anyone else?

[Ljohnsaw]

The round thing is not a knob, it's a transistor, or resistor, or something.

Capacitor

[Southside]

On mine the adjustment knob was on the motor side.  Thinking about it the adjustment was to dial in the Hz, but it changed the motor RPM. What are you showing for Hz at that voltage? 

[scsmith42]

If it were me, I'd check the voltage and hertz under a load. If both are high, decrease the governor linkage a turn or so until it within spec.

[sawguy21]

Is it gas or diesel drive? If gas a wireless tachometer held near a spark plug wire would give you engine speed. There are cheap ones that are reasonably accurate that use a wire wrapped around a spark plug lead creating an induction coil. I am not that familiar with diesels. Scott's method is more accurate if you have the proper tools.

[trimguy]

It's diesel. Can you check Hz with a voltage meter ? I have never had to check that before. I have never worked on a generator before, either . I will have to look at mine.

[scsmith42]

It's diesel. Can you check Hz with a voltage meter ? I have never had to check that before. I have never worked on a generator before, either . I will have to look at mine.

My Fluke will measure hertz, but my Ideal won't so it depends on the multi meter.
My 400hp Kohler has an adjustable voltage regulator. You dial in the engine rpm to achieve the correct hertz, and then adjust the VR as needed.

[trimguy]

I just walked out to the shop and looked at my voltage meter, it will not do Hz. I will see if I can find one I have to work tomorrow. I was thinking this was going to be a plug and play situation, once again I was wrong. Thank you everyone for the help so far.

[Southside]

It may be that the previous owner ran it full load or even over a lot so they kicked her up a bit to be over voltage with no load.  I am presuming you want 240V?  Should not be hard to address.  

Edit: I guess I take that back, looked at your tag, it says 208.  Have you checked the taps to be sure someone didn't cross a couple of lines?

[trimguy]

As in taps, I guess you mean the wires coming out of the generator that are numbered, one, two, three,...... this was originally set up for 110 V when The previous owner bought it. He had someone change some of the wire number connections to make it three phase Output.He didn't know what had been done . Just hired a electrician switched it over and hook it up to make his saw work.

[moodnacreek]

My 208V side is around 217V and that is fine for motors. As mentioned you could be running a little fast. 

[scsmith42]

As in taps, I guess you mean the wires coming out of the generator that are numbered, one, two, three,...... this was originally set up for 110 V when The previous owner bought it. He had someone change some of the wire number connections to make it three phase Output.He didn't know what had been done . Just hired a electrician switched it over and hook it up to make his saw work.

If you have a 12 wire alternator you should be able to rewire it into 240 or 480 3 phase.   Sometimes 240 single phase too.
The 12 wires should be labeled and the voltage output will depend upon the sequence in which they are combined.

[trimguy]

I bought a new voltage meter that will do Hz. Running with no load is 258 V, 62.5 Hz. Under load, the tablesaw read the same. Under load the planer drops to 116 V 33 Hz. The engine dropped way down on RPMs, tells me the governor is not kicking in. This is a Duetz F2L912. The tachometer that I ordered to check the RPMs won't be in till end of next week so I don't know exactly what they are. This is a 12 wire alternator. There is what appears to be a factory tie wire on the throttle setting, for whatever that's worth, I know parts wear. My questions are, Is a 62 Hz fine or is that to high ? Does anyone know about the governor on these? Where its at? I'm assuming by the fly wheel, but if anybody has any information before I start tearing apart would be great. I don't know anything about this set up.

[sawguy21]

It seems you have two problems. First the voltage is way too high, either the engine is overspeeding or the voltage regulator has gone awol. Secondly that rpm and voltage drop trying to run the planer tells me the engine is not up to snuff and somebody tried to jerry rig it. I suggest having a qualified mechanic look at it before you get in over your head, it will be money well spent.

[trimguy]

Thanks sawguy, but I do hope your wrong. My son knew somebody That had a tachometer, At idol is 1862 RPMs, with the planer on 968 RPM's. The tag all the engine says 1800 RPM. Shouldn't there be a governing system On this to kick the RPMs back up when a draw is put on it??

[moodnacreek]

This voltage output is confusing. If it is a 208 as tagged I think 1 lead would read 110V. If it has been reconnected for 480V, one lead to neutral should read 277V.  257V is right in between and I don't think the rpm is far enough off to do that but it's not dead so there has to be a fix.

[trimguy]

Mood, I agree there has to be a fix.😁 I just don't know what it is. 

 

I was tinkering on it earlier and had to do an eviction. It didn't fix my problems though. Tomorrow I will get how the alternator is wired.

[Southside]

What voltage do you want?

[trimguy]

I thought I wanted 240V ?? Is there an upside or downside to 208v versus 240v ?

[Southside]

Well technically 240V would draw less for the same work, but it would not really be an appreciable number.  The important thing is what voltage your motors are set up to run at.  

[trimguy]

 

 

 

 
Here is the tags off my 3 machines. 208v on all , and 220-230 on all. I don't know that it matters to me as long as I can get them all to work.

[Southside]

The only common voltage to all three is 208. The first one is 208/220  You have an alternator that is specd for 208.  I would check the taps, set it up for 208, verify voltage, and call it a day.  

[trimguy]

This voltage output is confusing. If it is a 208 as tagged I think 1 lead would read 110V. If it has been reconnected for 480V, one lead to neutral should read 277V.  257V is right in between and I don't think the rpm is far enough off to do that but it's not dead so there has to be a fix.

Is this right, 208v then one lead should be 110 ? Thanks southside , I hope to get a chance to mess with it today.

[Magicman]

Regardless of the voltage, the Hz has to be 60Hz  (cps)  and the correct RPM/load should keep it there.  The governor has to function properly.

[21incher]

This may not be relevant here but to check my RV generator volts and hz I had to use a meter rated for true RMS otherwise the readings were not accurate. I have no idea what the difference was.

[moodnacreek]

This voltage output is confusing. If it is a 208 as tagged I think 1 lead would read 110V. If it has been reconnected for 480V, one lead to neutral should read 277V.  257V is right in between and I don't think the rpm is far enough off to do that but it's not dead so there has to be a fix.

Is this right, 208v then one lead should be 110 ? Thanks southside , I hope to get a chance to mess with it today.

That is correct, with 208 service you get 110 off 1 lead and 208 single phase off 2 [if I remember] and 208 3 phase of all three leads. This means if you need 110 for controls or anything you don't need a transformer.

[scsmith42]

My advice is to fix the governor problem first, as that is most likely the source of your high voltage at low load and low voltage at high load problem.

Once the governor is operating properly you can tweak it for the proper voltage.

Personally I'd set it up for 230VAC at 60Hz.  208 will require larger wires and 220 / 230 are basically interchangeable voltages as far as the motor's are concerned.

[trimguy]

The tester I picked up just happen to be a true RMS. And that's where my luck ran out. Found wiring diagram to wire to 208 bolts. I wired it up, Everything checked good. Plug the tablesaw in, Everything's good. Plug the planner in, Everything's good, RPM's dropped to 1664 and the planner was up to speed. Was checking a couple other things, the planner started to slow down, how old out to the generator it was idled down And the magic smoke was coming out of the alternator. Now it is locked up. I'm just a little ticked and frustrated with myself at the moment. I want to thank everybody that commented and give me ideas to do on this, I really appreciate it. Now I have to figure something else out I guess.

[mike_belben]

Sorry to hear man.  


Does it have a belt drive "hoof" governor?  

[Oliver05262]

I know you said the smoke was coming out of the alternator, but I would be concerned about piston damage that occurred before you found and removed that rat's nest around the cylinders. The air cooled Deutz engines do not tolerate restrictions to the air flow and I've been down that route. Got real acquainted with Mike's old employer in Ludlow, MA.

[mike_belben]

I did work there for a spell, grew up right down the street. 

[hedgerow]

I know you said the smoke was coming out of the alternator, but I would be concerned about piston damage that occurred before you found and removed that rat's nest around the cylinders. The air cooled Deutz engines do not tolerate restrictions to the air flow and I've been down that route. Got real acquainted with Mike's old employer in Ludlow, MA.

I totally agreed with this statement. I would hate to guess how many air cooled Deutz and Wisconsin engines I have had to overhaul because of mice nest. They don't run very long with the air fins plugged before its scored a piston and cylinder. I don't even start one that's set very long without opening up the tin on the engine. 

[trimguy]

Mike, I'm going to say it doesn't. Does that make it better or worse ?


I ran it a couple of times after I cleaned the rats nest out. I realize that the damage could have already been started. Maybe that's better news, the engine could be rebuilt . I don't know if that alternator can be.When I get a chance I will Separate them and see which ones locked up. I have a lot going on, probably shouldn't have taken the time to mess with it. But, I was a little excited, just wanted to run one board through