? for those of you with an ST generator

[tinkerer]

Hello! I'm thinking of buying a ST generator head for my Yanmar project and had a question for those of you who own and use a ST head. Here it is : If you had to buy another head, would you buy another ST head? Have you had good luck with it? Any problems? Would you recommend a ST head?  By the way, my generator will be used as a backup generator. We usually end up using a generator, on average, a week total out of the year. We have had a few times we were out for a couple of weeks.

THanks!
Ben

[luv2weld]

I guess my recommendation would depend on your abilities and mental attitude toward maintenance.
And a little bit influenced by how much you want (or are able) to spend.

I think the ST's are great. But for a little more money, you can get a permanent magnet generator that
has no brushes. The only maintenance items would be the bearings. But you have to be more careful
around it. No welding, grinding or anything of that nature anywhere around it.

I have heard that the PM (permanent magnet) generators do not give the pulsing lights that the ST's give.

Ralph

[rl71459]

Hi Ben

I have a ST-12 direct coupled to a Isuzu/ThermoKing C-201 4 cylinder Diesel. I bought it on E-Bay
already built up this way. I have had it for 5 years now. It is obvious that mine has never been apart
(No Tool Marks or chipped original paint) I use it at least 6 times as often as you describe... Plus whenever there is an outage.

The Dog House did have all the screws replaced over time, and the wires to the volt meter have broken long ago.

But... It still has the original Brushes and bearings. As far as the power it produces, Everthing runs the same as on the grid, No flicker, I have central air as well as a Small machine shop 2 Lathes (1Ph Small)
2 Mills (3 Ph Bridgeport clones) 1 Surface Grinder (3 Ph) Drill Press, Welder, Air Compressor. The 3 Phase equipment is operated Via Home Brew Rotary Inverter (Motor w/Cap Start). Note: the shop never has all equipment running at the same time, But very often we will run 2 thru 4 machines simultaneeously and can do so while on the genny.

All that said... I am not very impressed with the appearance of the unit. It definetly resembles its cost!
(CHEAP!) Frankly, I expected it to fail long ago. And I am certain it will, Probably when needed most!

Rob

[Tom Reed]

I've got an ST5 with just over 1400 hours on it. It was used to power the construction of our off-grid home and is now doing duty charging batteries on cloudy days. Mine had the rectifier go almost immediately, the bearings go at about 100 hours and had a connection in the windings break at 850 hours. Since then there's been no trouble with it.   Fortunately it's been very repairable in the field so it's got that in it's favor. I'm now looking to replace it with a 3ph industrial motor to use as a dc generator to charge batts directly.

[tinkerer]

Thanks for your replies. I am fairly mechanical and I don't think I wouldn't be afraid of working on a generator. I've  overhauled engines, transmissions, automobile generators and alternators, starters and such. I'm the kind of person that would rather fix something thats broken rather than buy something new. but... with all that said, I don't want this thing to fail me when I need it the most. I can live without lights, AC, TV, etc.. but the main reason we need a backup generator is for our freezers and fridges and to run the well. It only takes one major generator failure and your freezers of meat and other produce are spoiled. It would only take one major breakdown and you could buy a little better generator head. We do have a small consumer "screamer" generator that is getting some major time on it. I know that sooner or later its gonna fail and my guess is "sooner" rather than later. I've worked on it some and I know its not something worth fixing. Thus the reason for building this setup with the small diesel yanmar.
I have done quite a little reading about the ST heads and they all seem to have a few bugs. If I could buy one and before I even use it, replace the bearings with better quality sealed ones, replace with a quality rectifier, make sure all connections are good and know for sure that its not gonna fail me I would definitely go with the ST. Even if the rectfier or a brush failed while using it, I could live with that kind of breakdown. What bothers me, is if something goes wrong with the stator or rotor while using it that I couldn't fix. Something that would require a motor or generator shop to fix. Are these kind of failures common? I know that these kind of failures could also happen with a better quality generator heal also. Maybe I'm being to paranoid, lol, but I just want this thing to be as reliable as it can be.  With that said, What do you guys think?? ST or no ST??

Thanks!
Ben

[sailawayrb]

As a backup generator and given the amount you indicated you will use it, an ST should easily outlive you!  The only thing that might bite you would be to lose the residual magnetism because of long lack of use or because you leave it connected when you shutdown your prime mover.  So you would want to be well versed in how to flash the field should this ever occur.  PMGs have the advantages previously noted (plus PMG would likely survive an EMP event if that's a real concern to you) but PMGs are also more expensive and have the issues previously noted.

I immediately got rid of dog house crap and just added a connector box:

http://listerenginegallery.com/main.php?g2_itemId=351

Bob B.

[vdubnut62]

Tom Osbourne @ Central Georgia Generator has brushes, bearings, commutators and voltage regulators for cheap.
I have 5 rectifiers salted away. Tom's units are copper wound so the above are about the only parts you should need.
ST's  are cheap, hard to kill and easy to fix in the field. If they aren't running, an EMP won't kill 'em.
Ron

[mbryner]

Agree w/ sailawayrb & vdubnut62.   I have a ST 7.5 w/ about 600 hours on it -- no troubles at all.   I also have backup brushes & rectifier from Tom Osbourne.   I don't expect problems, but I also keep a gas screamer in a container just in case the ST or Listeroid need something.

Marcus

[Ronmar]

Same here, have an ST-5 with about 150 hours on it.  I replaced the bearings and doghouse and use a solid state rectifyer.  Very easy to work on, and mine puts out pretty good power.  I am looking at another, larger one to make a tractor PTO generator:)...

[Geno]

I've got over 4000 hours on an Utterpower ST-5. I took it apart when I got it, replaced the bearings and sprayed it with Glyptol. I've gone through a set of brushes and had it apart another time to clean it and repair a wire that was rubbing on something. It runs a pretty sensitive inverter once there's a load on it and has served me well.

Thanks, Geno

[akghound]

I have an ST12 with thousands of hours on it. It has been our primary powe since 2007. We live off grid without solar or wind supplement. All ourelectrical  power comes from it. I have had to replace the brushes and of course replace the factory rectifyer with one fvrom Utter Power. Check out the Utter Power site for all the info on these you will ever need.

[tinkerer]

Thanks everyone for sharing your opinions and experiences!  I have decided that I will probably go with an ST head for my project.

Thanks!
Ben

[cujet]

I have an ST-15, powered by a twin Listeroid. If I were to do it again, I would purchase a higher quality generator head. The ST-15's waveform is not great and looks like many of the pictures posted on these forums. So, mine's not worse, but I find it difficult to deal with. I cannot run some of the computer UPS' in my house on the ST generator. Yet, my Subaru 5500W genset does fine. My ST only produces 109 volts per leg. So I had to use a "special" voltage regulator that uses one of the 120V legs as excitation power. I'll bet that "special" regulator is easy to find in an emergency,,,not.

What I find interesting is that a higher quality unit is not that much more expensive $600 for the ST and about $900 for a "real" gen head. And, you don't have to deal with replacing bearings, brushes, applying glyptol, installing a better rectifier and voltage regulator.

[tinkerer]

Cujet,
       Thanks for your input on the ST and for sharing your experience. I was curious what is the brand of the generator you can buy for $900 that is superior to the ST? Just curious as any quality brushless unit I looked at was around $12-1500.

Ben

[sailawayrb]

I think the waveform quality that people experience from their ST is more a function of their setup than anything else.  We know the Listers and Listeroids introduce a 5 HZ frequency because of the nature of their power stroke.  We know the magnitude of this 5 HZ frequency is larger for the twins than for the singles everything else being the same.  We know if you wire your ST for 240 (instead of 120) and one doesn't keep the electrical loads perfectly balanced (i.e., via a balance transformer) you will encounter voltage sag and often hear growing sounds.  And than there are folks who get creative about "balancing" their Listers and Listeroids which has the potential of making the 5 HZ power frequency magnitude larger than it would normally be.

Bob B.