Author Topic: ST Heads in the Pacific NW  (Read 17036 times)

adhall

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ST Heads in the Pacific NW
« on: January 20, 2007, 05:43:36 PM »
I am looking for an ST head in operation and powered by a Lister(oid) engine anywhere near by. I live about 50 miles West of Olympia, WA.

My purpose is to make some electrical and mechanical measurements in order to help further the development of an automatic voltage regulator.

If you would like to help me out, please PM me.

Best regards,
Andy Hall
JKSon 6/1, 5 kW ST Head, 1992 Dodge RAM Cummins 5.9L Turbodiesel, 2001 VW TDI 1.9L Turbodiesel, 2006 Jeep CRD Turbodiesel, Yanmar FX22D Diesel Tractor

Copybell

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Re: ST Heads in the Pacific NW
« Reply #1 on: January 20, 2007, 07:39:35 PM »
Andy,
   I live on the other side of the country from you, however I am happy to make any measurements you require and relay that information to you.  My generator heads are ST models, one 5KW, one 15KW.

Copybell
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adhall

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Re: ST Heads in the Pacific NW
« Reply #2 on: January 20, 2007, 09:53:56 PM »
Copybell:

Thanks for the offer.

Here are some things I would like to measure:
  • Rotor resistance
  • Rotor voltage under load
  • Rotor current under load
  • Generator output and Z winding voltages due to residual magnetism only (i.e. no field current) at rated speed
  • Engine speed variation

The object of measuring the output and Z winding voltages with no field current is to determine if there will be enough voltage produced to power the regulator at start up. Before making this measurement, it is important that the generator be spun down with the load disconnected.

Measuring the engine speed variation could be done by coupling a DC tachometer (or a permanent magnet motor--even a "slot car motor" would do) to either the engine or generator shaft and measuring the maximum and minimum voltages generated.

If you have any questions, please let me know.

Best regards,
Andy Hall
JKSon 6/1, 5 kW ST Head, 1992 Dodge RAM Cummins 5.9L Turbodiesel, 2001 VW TDI 1.9L Turbodiesel, 2006 Jeep CRD Turbodiesel, Yanmar FX22D Diesel Tractor

Jim Mc

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Re: ST Heads in the Pacific NW
« Reply #3 on: January 21, 2007, 02:23:59 AM »
Another way to measure speed variation, assuming you don't have a digital scope:  Take the AC output from  he ST head, attenuate it 1000:1 and feed in into your laptop's audio line in.  Record the waveform, and then us a audio editor (Audacity, maybe-  used to be free...) to analyze/find the zero crossings. 


dieselgman

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Re: ST Heads in the Pacific NW
« Reply #4 on: January 21, 2007, 09:55:13 AM »
Andy,

The Chinese ST style generator head appears to be pretty much the bottom of the barrel for quality and technology but they do come with optional AVR packages from the manufacturer if so specified. If you or other list members are interested, I can forward more detail and also some suggestions for better quality generator heads for this application. There are many available that are better suited to North American and perhaps European functional standards, can be regulated to within 0.5% and have much higher quality control. I do not accept the substandard approach to these parts based on initial cost and I am surprised that so many accept the ST as the right combination for their Lister(oid) powered generator sets. After my first batch of these, I definitely will not install any more of them. In my opinion they represent a false economy just like the lower quality Indian Listeroid constructs do. I believe that most of us would prefer to own, operate and work on original Listers if they were readily available at decent prices, in the case of the genheads this is a clearly available option.

On the other hand, perhaps there are those who welcome the challenge of repairing a new engine or resolving the myriad little problems that result from a poorly executed manufacturing process that lacks accountability for quality control. To each his own, but I am not one of those types. Just give me good quality for my $$$ and leave the real junk in the third world where it originated.

Gary
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ALL Things Lister/Petter - Americas
Lyons Kansas warehousing and rebuild operations

hotater

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Re: ST Heads in the Pacific NW
« Reply #5 on: January 21, 2007, 02:31:26 PM »
Gary---

How many ST heads are you basing that on!?

I have two of them....one is as you say.  The other is a VERY well made genhead.  The paint is the same. The looks is the same, until you get inside and then it's a totally different machine.

Quote
After my first batch of these, I definitely will not install any more of them.

Maybe you bought a bad batch of heads?   
« Last Edit: January 21, 2007, 02:34:30 PM by hotater »
7200 hrs on 6-1/5Kw, FuKing Listeroid,
Currently running PS-Kit 6-1/5Kw...and some MPs and Chanfas and diesel snowplows and trucks and stuff.

mobile_bob

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Re: ST Heads in the Pacific NW
« Reply #6 on: January 21, 2007, 04:05:40 PM »
Tater:

i think you made a valid point,

when for instance a st5 can be had from anywhere between 145lbs and 245lbs,, you gotta wonder which ones he ordered.

it stands to reason that the light heads , are probably not only light on iron, but light on copper as well, which makes for more issues.

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

hotater

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Re: ST Heads in the Pacific NW
« Reply #7 on: January 21, 2007, 04:21:24 PM »
I have to say, the first ST head was a great learning experience....and that's a major part of everything I get interested in.  It had more things wrong with it that suited my shop than I could have imagined from an electronic, and therefore TOTAL mystery, machine.

  It's heavy enough and sure not a light weight model, but the castings looks like they were done on an habachi grill with the roughest machining I've ever seen. 
 The shaft had .090 of end play and both bearing seats had been rough turned and then lathe filed to "fit".  Both seats were barrel shaped.
 The drive end bearing housing was so loose it eventually wore out til the rotor started rubbing  on the stator.  THAT will get your ear's attention, but the lights still burn.   ???

It blew the diode bridge (?) but George's little plate and replacement makes more sense than the original and is 'sho nuff tougher.

The new ST is it's littermate in the looks department and it has (had) the same chintzy dog house and silly red light, but inside...!  Inside it's VERY well fitted and finished...totally different from the castings to the fit and finish.   AND, it puts out power.  In my book that makes it perfect.      ;)
7200 hrs on 6-1/5Kw, FuKing Listeroid,
Currently running PS-Kit 6-1/5Kw...and some MPs and Chanfas and diesel snowplows and trucks and stuff.

dieselgman

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Re: ST Heads in the Pacific NW
« Reply #8 on: January 21, 2007, 05:22:54 PM »
I did not import my ST heads, I purchased from a well known supplier that everyone else mentions here, and paid the premium price. These were the very heavy heads but that is not the measure of a good device. No doubt these will suffice most homeowners' power needs until it comes to motor starting loads and more sensitive loads calling for close regulation or very clean sine-wave output. At any rate, I normally use the Marathon Lima MAC designs in all heavy 3-phase applications and Newage/Stamford for single phase.

There are Chinese manufactured equivalents to these - almost exact copies, and they are looking pretty good from all angles. I'll report our results here once we have hands-on the new products. 18 month warranties and the largest manufacturer of such hardware in China sounds pretty good from the start. BTW Cummins, Lister/Petter, and Perkins are OEM partnered with this outfit.

As far as voltage regulation and the ST heads go, I made mention of the fact that the manufacturers offer this option as well for this head, just in case someone is trying to 're-invent the wheel' because they didn't know this option was available for resolving some of the issues present in the basic design. The bare single-phase ST is the cheapest 4-pole generator head out of China.

Gary
diesel-electric.us
ALL Things Lister/Petter - Americas
Lyons Kansas warehousing and rebuild operations

Jim Mc

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Re: ST Heads in the Pacific NW
« Reply #9 on: January 21, 2007, 06:38:17 PM »
...I can forward more detail and also some suggestions for better quality generator heads for this application. There are many available that are better suited to North American and perhaps European functional standards, can be regulated to within 0.5% and have much higher quality control. I do not accept the substandard approach to these parts based on initial cost and I am surprised that so many accept the ST as the right combination for their Lister(oid) powered generator sets....

I'm curious.  Say a guy decided to use a Newage Stamford 10 kVA single phase, 4 pole, 2 bearing head.  What might he expect to pay for that?  Value is a performance/price ratio.  I've no doubt these are better made, but we need to know the price to assess the value ourselves...


mobile_bob

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Re: ST Heads in the Pacific NW
« Reply #10 on: January 21, 2007, 08:00:17 PM »
Gary:

you made a few points

1. you seem  to be of the impression that an st head is deficient in motor starting capability.
compared to what? if there is one thing they seem to excell at, it is motor starting.

2. i suppose they might be overall less of a gererator than a stanford newage or lima or some other american generator, but at a small fraction of the cost.
not many folks want to or are able to spend 2 grand up, for a genhead

3. the st head for what it is, is a tough reasonably well regulated, reasonably clean power source,
sure it has some wave form issues, but not many folks have a need for many kwatts of pure sine wave power, and for what they need in pure power there
are better ways of getting it than through the use of a high price generator head.

4. a relatively handy DIY'er could if pressed, tear down his st head, and with a pencil, paper and a few digital pics, stip and rewind it if the need arises.
the US heads are out of the reach of the average DIY'er when it comes to repair.

are they perfect, no... nothing is perfect. Genheads just as all mechanical things have inherent issues, so you make some comprimises
for my dollar the st head is damned hard to beat.

for 1/4 to 1/5 the price, i can arrive at many ways of handling my critical need pure sine wave needs. the st head is more than sufficient to handle all other needs.

i am curious though,,, what loads can you not start with your st head? were you not sized correctly? did you try to start a 10 kwatt load on an st head driven by a 6/1?
your report seems  drastically in the minority of users reports.

bob g
otherpower.com, microcogen.info, practicalmachinist.com
(useful forums), utterpower.com for all sorts of diy info

dieselgman

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Re: ST Heads in the Pacific NW
« Reply #11 on: January 21, 2007, 10:15:07 PM »
I expected this to generate some heated responses based on what I have read in the Forum. I do agree about the price/performance ratio that applies to common sense decisions in these things. We are after all, putting a $120 device along side a $1200 device or trying to compare a Chinese KIA to an American Cadillac. The comparison is inherently unfair simply based on that ratio. I am also somewhat bent towards the higher end products because this is the quality level our customers have come to expect and sometimes demand in America. The price comparison really is a factor of 10 in real numbers (not 1/4 or 1/5) when putting the ST alongside a Marathon. Shipping will be comparable for any heavy chunk of copper and steel - good, bad, or otherwise...

Leaving the American $2000 heads aside, there are a large number of other options that would make a viable discussion here though. From the best Chinese manufacturers we can identify many variants of the ST head and copies of the high-end heads for anywhere from a very nominal price increase to about triple the going ST price. They would include  ST with AVR, STC, STT, SLG, SFPW, SD, SDC, TZH, TFW models. My business model calls for evaluating quality above price but knowing full well that many on this forum and elsewhere have limited budgets; I will be importing and doing further analysis of the current options. If we come up with some contenders, they will come to the forefront. Some of the other European designs also appear worth looking into. French and Italian models ...

I have heard or read many reports of various problems with the ST heads and I'm sure that a big part of what we are hearing about represent the variances from different low-buck manufacturers. This is an avoidable pitfall.  Fortunately, China presents a different business culture altogether from that found in India and I have been pleased with their responsiveness to the priority of needs inherent elsewhere in the world. It is hopeful and probable that these are going to be the new premium players (despite the negative impacts and adjustments caused in other economies).

Anybody interested in a good Marathon copy at 1/3 the price if all other quality and design factors are addressed??? This is what we will be assembling and offering with our original Listers. More later on...

I know that AVR devices will defy the average DIY person when it comes to diagnosis and repair but that is generally handled by simply having a spare on hand to swap-out. As to rewinding and repairing rectifiers/rotors/stators, equal skill and difficulty is presented by any of these devices. Except for some of the Euro designs using metric wire sizing, it is hard for me to see anyone judging one rewind more difficult than the next. Not a job many would undertake but still possible given the right knowledge, tooling and supplies.

Gary
diesel-electric.us
ALL Things Lister/Petter - Americas
Lyons Kansas warehousing and rebuild operations

duh

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Re: ST Heads in the Pacific NW
« Reply #12 on: January 22, 2007, 12:01:54 AM »
I've read the comments regarding ST heads, AVR, etc...

Having one myself mated to a 6/1, I use it extensively (for emergency use only right?)
Anyway, I have at least one household item that is fairly picky regarding AC: a Toyostove heater (Laser 73).
The Laser rejects the rock solid 120v 60hz modified sinewave output from the Trace 2412 (goes into error and shuts down) - however - it has no problem with the 6/1 ST3kw combo.

Below are two links to pics (1 of a volt track over a few minutes, the other of the Hz track for the same amount of time), and in addition to varying AC loads during the tracking, the DC side was pulling 50 amps and tapering back while supplying power to varying DC loads.... The gen head has no AVR and the test was conducted when engine was at operating temp and maintaining a scorching 375 rpm....

http://www.diesel-bike.com/Lister_Gen/ST_Voltage_track_375rpm_OnEngine.JPG

http://www.diesel-bike.com/Lister_Gen/ST_Hz_track_375rpm_OnEngine.JPG

duh

Copybell

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Re: ST Heads in the Pacific NW
« Reply #13 on: January 23, 2007, 03:18:15 PM »
Andy,

   Here are the measurements you requested:

     GENERATOR - Type ST-5   5KW rating  Wired for maximum amperage into a single 115V leg

     ENGINE - 6 HP Listeroid running @ 650 RPM

     LOAD 1,800 Watts

     Speed (Hz) is measured with a Kill A Watt meter

Rotor resistance - 15 ohms

Rotor voltage - under load, 58V 60HZ       no load, 30V 62HZ

Rotor current - under load, 1.69A 60HZ    no load, .87A 62HZ

Generator output residual magnetism only  4.8V

Z winding residual magnetism only 3.6V

Best regards,
Copybell
Omega brand 6/1
Fuking brand 6/1
Satyajeet brand 20/1
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adhall

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Re: ST Heads in the Pacific NW
« Reply #14 on: January 23, 2007, 11:11:11 PM »
Hi Copybell:

Thanks very much for your trouble and thanks also for the very useful information. There's nothing like some hard facts to clarify the mind.

I have to say that I'm dissapointed in the low output voltage without excitation. But it is good to find out about it now.

Out of curiosity, do you have any sense of how long it takes your generator to come up to full output? Does the voltage come up quickly or does it take a little while?

Also, have you ever had a time when the generator would not excite? If so, can you tell me what conditions led to that?

Best regards,
Andy Hall

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Hi duh:

I see that you posted a couple of days ago and I didn't notice it until today--sorry about that.

Thanks for the traces. Can you tell me what your sampling rate was on those? And would you be willing to send me the raw data you sampled to make the traces? (If you are, just let me know and I will pass along my personal e-mail address to you by PM.)

Best regards,
Andy Hall
JKSon 6/1, 5 kW ST Head, 1992 Dodge RAM Cummins 5.9L Turbodiesel, 2001 VW TDI 1.9L Turbodiesel, 2006 Jeep CRD Turbodiesel, Yanmar FX22D Diesel Tractor