ST AVR upgrade

[gusbratz]

Hello to all, new to the fourm and lister's as a whole. I have been bit by the lister bug and am in the process of building a backup generator. I have ordered an 8/1 clone engine from diesel electric services and already had bought a 10kw st gen head off ebay. the st head appears to have no avr at all. just a dimmer that I can vary the field voltage with. I can't imagine that we would be satisfied with having to go out to the power house and adjust the voltage every time mama turns off the tap and the well pump kicks on and of so how hard is it to add an avr? I am tempted to buy one off ebay but now quite sure how many amps of field current it will pull or what avr to buy.  cunntly looking at these ones.

http://www.ebay.com/itm/New-1pcs-Automatic-Voltage-Regulator-for-Marathon-AVR-SE350-US2-/281480343045?hash=item4189892e05:g:nEAAAOxyLchRrECj

or
 
http://www.ebay.com/itm/282089253919?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

[dieselgman]

We use the 240volt harmonic-compatible versions sold by Tom at CGG. He has already gone through the trouble of vetting a variety of these types and settled on a couple of brands that perform properly and have minimum failure rates. Wiring in series with the harmonic winding works well... should go in place of your rheostat.

dieselgman

[BruceM]

CGG wasn't carrying the 240V units last I knew. Do NOT use the 120V for 240V, at least on the ST-3.  Even that tiny load imbalance makes noises on an ST-3.

The GB-160 AVR design is carried by a lot of sellers in China on ebay.  It is the 240V version identical to the 120V unit CGG carries.  These 240V units have worked well on my neighbor's St-3.  The 120V one from CGG failed in a few months.

http://www.ebay.com/itm/311412889591?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

The seller is:  ashleytrade1984* (14700 )
99.4% Positive feedback

We ordered a spare recently, worked fine, got it 2 weeks for $24 including free shipping.

By the way, the rheostat should be a one time, fixed adjustment, so long as you can live with a bit of voltage drop between unloaded voltage (set high) and full load voltage.  If you must have constant voltage regardless of load, the AVR is your best choice.

Best Wishes,
Bruce

[dieselgman]

Yes, it is the GB-160 that we have tried and had good results with - so far.

dieselgman

[mikenash]

CGG wasn't carrying the 240V units last I knew. Do NOT use the 120V for 240V, at least on the ST-3.  Even that tiny load imbalance makes noises on an ST-3.

The GB-160 AVR design is carried by a lot of sellers in China on ebay.  It is the 240V version identical to the 120V unit CGG carries.  These 240V units have worked well on my neighbor's St-3.  The 120V one from CGG failed in a few months.

http://www.ebay.com/itm/311412889591?_trksid=p2060353.m2749.l2649&ssPageName=STRK%3AMEBIDX%3AIT

The seller is:  ashleytrade1984* (14700 )
99.4% Positive feedback

We ordered a spare recently, worked fine, got it 2 weeks for $24 including free shipping.



By the way, the rheostat should be a one time, fixed adjustment, so long as you can live with a bit of voltage drop between unloaded voltage (set high) and full load voltage.  If you must have constant voltage regardless of load, the AVR is your best choice.

Best Wishes,
Bruce


Hi guys

I just took delivery of a ST5 from China yesterday down here at the bottom of the world - haven't even opened the crate yet.

I suspected it would have an old-fashioned mechanical voltage control in that dogbox - but maybe not?

I'd be interested in any experience-based thoughts on the things - you hear stories ranging from folks who love the simplicity of design to folks who regard them as only fit to weld a length of anchor chain to . . .

I'd be happy to, say, fit SKF bearings and a modern AVR?

My intention is for it to drive a large 24V charger for the battery bank when the sun isn't shining - and I guess take advantage of it's running to do anything needing the angle grider or the welder at the same time . . .that sort of approach

I'd appreciate any wisdom

Cheers, Mike

[BruceM]

I would recommend checking your rotor and stator windings on any ST head to make sure that they are copper.  If aluminum, consider the boat anchor application unless it is for a show piece where long term reliability is of no concern.

The only thing going for ST's is the price, and the lack of other choices until over triple the price for 4 pole, 1800 rpm head in the 3-5KW range. The variation between different units, even from CGG, is dismaying and includes the use of aluminum on rotor windings, huge variation in Z winding output, failures of Z windings. Winding failure on copper windings suggests the use of substandard insulation.  I'll know more when I've done some testing with a new mega ohm meter.

For the larger heads, Gary of DES has recommended the Stamford clones as being a good, reliable choice.  I would take his technical advice to the bank, myself.

[gusbratz]

i ordered my 10kw generator on ebay before i contacted des. it was 390$.  the inspection date on the shipping crate says apr of 1999 so not sure if it is old stock or what. i was surprised to find a spring mounted doghouse and amp hz and volt meters on it. i will be removeing the doghouse to build my own control panel. It looks to have copper winding in it unless they are copper coated AL.  i may bring the megger home from work and check the winding insulation before i run it so i have some base line readings.

[Tom]

Wow  that's a delux one.

[dieselgman]

Current crating technology (and for as long as I have been importing them) is of light plywood and metal brackets. That one has been sitting in a garage or back shelf for a very long time. The unit looks pretty nice with the extra hardware and instruments and you got an excellent price! Bearings and brushes are the first things I would inspect though - then the winding connections.

dieselgman

[mikenash]

I have been looking for an ST at a sensible price for literally years here. Looks like I night be too late to get anything worth while having.

Hi Mr Glort

FWIW I imported one from China to NZ:

$427 USD incl freight to port of Wellington

Something like $170 NZD handling at port

And about $140 NZD customs charges

Cheers, Mike

[38ac]

When electric is the topic I should be sitting on the bench but you might want to try the unit as is prior to adding the AVR?  I think ( maybe bad idea?)  that a 10KW head  is a different animal for feeding house loads than a 3 or 5 due to the fact it is not heavily loaded? Engine governing is of course a huge factor also. My ST head experience is slim as compared to Gary or the off grid folks here  but our stand by set is a 15KW ST powered by a 23HP rattle bang China diesel and I have yet to see the need for an AVR.  We have one of the new fangled processor controlled furnaces, and other house hold gadgets plus the well pump load and we live like the grid power is up when running the stand by set. We keep a Kill-o-watt meter plugged in when ever the standby set is running and the voltage stays at 122-125  I bought those #160 AVRs when we bout the heads (2) and they are still in the box.  Its one of those why add unneeded complication deals with me because when something stops I am challenged to find the problem. You should by an extra rectifier or two because the OEM one will fail under first heavy load  no matter which design it is.  I bought a bag of regular 1050 ( I think, been too long)  Bridge diodes on Ebay for cheap and bolt them to the metal box for heat sink.

[Tom]

I too have an AVR sitting on the bench. The ST5 with a balancing transformer works just fine on the harmonic windings as long as the RPM's are right. If the Z windings go out the AVR is plan B.

[gusbratz]

i may go that route, for now i ordered 2 gb160 avr's off ebay and will try and see how they perform compared to the rheostat. i took the generator apart and cleaned and repacked the bearings last night. now it is all back together. that 10k rotor is a real handfull to slip back in without scraping it along the windings. very heavy. i also installed zirk fittings on the bearings and screen on the bottom where the mice will try to get in. my 8/1 clone arrived in the mail today so i may start another thread and show how the process goes as i  pour a foundation and grout the engine.

[mike90045]

I have a spare diode bridge, and hope the Z winding never fails.

Electric wise, everything runs fine off the XW inverter.
 The 120V garage door opener does not like the Listeroid power.
 The electric spark ignitor for the gas oven, does not like Robin/Hatz/Subaru power.  Robin/Hatz/Subaru alternator has poor power factor capacity.

Till I get a scope out and look at the electric lines, I won't know for sure what it is.   Never did like plugging a scope lead into a wall outlet.

[mikenash]

When electric is the topic I should be sitting on the bench but you might want to try the unit as is prior to adding the AVR?  I think ( maybe bad idea?)  that a 10KW head  is a different animal for feeding house loads than a 3 or 5 due to the fact it is not heavily loaded? Engine governing is of course a huge factor also. My ST head experience is slim as compared to Gary or the off grid folks here  but our stand by set is a 15KW ST powered by a 23HP rattle bang China diesel and I have yet to see the need for an AVR.  We have one of the new fangled processor controlled furnaces, and other house hold gadgets plus the well pump load and we live like the grid power is up when running the stand by set. We keep a Kill-o-watt meter plugged in when ever the standby set is running and the voltage stays at 122-125  I bought those #160 AVRs when we bout the heads (2) and they are still in the box.  Its one of those why add unneeded complication deals with me because when something stops I am challenged to find the problem. You should by an extra rectifier or two because the OEM one will fail under first heavy load  no matter which design it is.  I bought a bag of regular 1050 ( I think, been too long)  Bridge diodes on Ebay for cheap and bolt them to the metal box for heat sink.

That's good advice 36, thanks

I have pretty close to zilch electronic skills and a tin box full of transistors & diodes and gubbins is a mystery to me.  So I'm a fan of KISS

Cheers