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Messages - BruceM

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Generators / Re: ST3 Noise and vibration
« on: Today at 01:30:15 AM »
Glad that it was just the usual ST-3 split phase snafu.  They can really moan and groan with sounds that say imminent failure.

You can carry a split phase situation with the ST-3 by adding a transformer with dual 115V windings, or adding two transformers  with 115V secondaries if you need more than 1500W of power.  The load on each 115 split phase must be below the rating for that secondary winding.  Spendy and a bit wasteful (40 watts iclle current for 2- 1500W tranformers) but its the best you can do with an ST-3, typically.

You can drive the Antec primaries with either 115 (primaries in parallel)  or 230V (primaries in series).

Regarding grounding of the neutral.  Sure, its nice to have the neutral grounded in one and only one location- if you ever intend to power the greenhouse from the house service - or someone might do that via extension cord, then making the greenhouse a normal code compliant sub panel with separate neutral and grounds being supplied by a grounded neutral/safety ground generator is probably best- assuming generator unplugged if house power is connected.  If the greenhouse was remote and so the generator is the only potential power source, then it could be set up just like main panel with the grounding rod connecting to the ungrounded generator ground and neutral tied to that at the panel.

Multipoint grounding of the neutral is a no-no as it causes current to flow through the safety ground which can then act as an "alternate neutral".  Bad news as the safety ground is NOT intended to be a current carrying wire within the home, it should be a relatively safe earth ground except only for clearing faults in an emergency.

Generators / Re: ST3 Noise and vibration
« on: December 06, 2023, 04:36:56 PM »
The ST-3's that I have experience with all can not tolerate ANY load imbalance.  Nothing to be done except to run either 230 or 120V. If you need both, step up or down via transformer for the smaller load, or step down near point of use if going some distance.  I recommend for high efficiency toroidal transformers.

I have also used smaller transformers in parallel to increase capacity with a suitable fuse for each transformer. The Antek transformers will handle huge surge loads.  A warning-  because of the high efficiency wound silicon steel cores, they do have high inrush current so soft start may be required on something like an inverter.  The ST-3 has no trouble with them.

I will note that I have seen significant variation in ST-3 stators, in particular, along with great differences in harmonic winding and clearance between rotor and stator. These affect waveform distortions, regulation, etc.  A pity no one has yet identified a single source in China that is reliable and has consistent higher quality. 

Listeroid Engines / Re: is my water (cooling)tank too high?
« on: October 31, 2023, 05:36:41 AM »
Yes, I think that the diluted Aviation Gasket sealer trick (Hotater?) was originally posted about 18 years ago.  I also tried it and it worked great.

Listeroid Engines / Re: Excavating the Pit of Doom
« on: October 12, 2023, 03:07:52 PM »
Plastic concerns me for the area near the hot exhaust inlet.  Also, by price I think Hugh's setup with concrete blocks is likely much cheaper.  I'm just surprised at the amount of carbon black he has collected.  Makes me concerned for the 3 inch  leach field rock approach though it will hold a large amount before being choked off. We  perforated a pipe section about 8 feet long at the inlet.   There is not much coming out of the 4 inch PVC perforated section (standard for leach fields) with riser at the end of the trench- no sound, no pulses of air, and just the smell of earth.

Hugh's pit fuffler has the advantage of being readily serviceable.  We may have to dig up the trench near the inlet perforated pipe at some point for my neighbor's setup, but since its propane, it may be a long time before that is needed.

Listeroid Engines / Re: Excavating the Pit of Doom
« on: October 12, 2023, 04:12:43 AM »
Hugh's high soot quantity in his pit type muffler points out the need for an exhaust viewing capability with pit or earth (leach field) type mufflers.

On my neighbor's 8/1 conversion to propane,  we put in a T in the 2 inch pipe leading to the leachfield muffler and put the stock Pot type CS muffler on that  (knee height) while we were working out the bugs on the conversion (which is still running well).  The pot muffler is still useful whenever there is some cocern about engine health.  Normally the Tee is plugged and normal flow is straight through with no restriction or turn.


Generators / Re: Voltage drop on only 1 120v leg, 7.5KW ST head
« on: September 22, 2023, 01:00:40 PM »
38ac's good experience with the ST-15 for asymmetric 120V loads is normal-  it seems the smaller ST heads have more of an issue and most are best run at all 230V or all 120V.  I was hoping your 7.5KW ST head would be OK.  (And it almost is.) I use a step down transformer for 120V loads at my shop to avoid the problem. There is a great deal of variation in "ST" rotors and stators, at one time I had three ST-3's on my bench and all 3 of the stators were  different in length and wiring configuration.

Maybe for your application just knowing which leg handles the big asymmetric load better will be enough?

Generators / Re: Voltage drop on only 1 120v leg, 7.5KW ST head
« on: September 22, 2023, 03:19:44 AM »
Thomas's  "check connections" and PowderMonkey's comments are both good, the latter if you have an AVR with 120V, single leg sensing, which is a bad idea. 

You didn't mention an AVR.  Is is using the stock harmonic excitation?
Is this a new problem or have you never tested large 120V , asymmetric loads?  I ask because many (smaller than your ST-7) ST heads moan and vibrate badly with such a load, and regulation not good.

My first thought is to go over the basics via ohm meter:

I'd check the resistance of each set of the stator windings looking for a difference in values and documenting the resistance for future reference..

I don's see brushes or  the rotor as likely culprets due to the 120V leg voltage asymmetry.  But it never hurts to check connections, and document resistance of the rotor coils for future reference.

Best Wishes,


Generators / Re: ST head indicator light question?
« on: June 16, 2023, 02:42:35 AM »
Butch, I looked and did find an ebay seller with indicators offered for a wide range of voltages; but they are different for each voltage range offered. They were all LED indictors.   For DC, a different resistor for each voltage range for current limiting.  For AC, a diode or diode bridge with capacitor between AC and bridge and then a resistor for current limiting.  These would be fine for an AC power indicator, instead of a neon bulb.


Generators / Re: ST head indicator light question?
« on: June 15, 2023, 03:56:58 AM »
Butch, I'm not aware of a universal voltage indicator lamp of any kind. 
I checked and it seems small neon night lights are no longer being made, they are LED instead.

The neon bulbs Glassblower linked to seem a perfect replacement element for your ST power indicator.


Generators / Re: ST head indicator light question?
« on: June 14, 2023, 07:58:42 AM »
You can get a neon power indicator bulb replacement at Digikey or Mouser, or even Amazon.
You can buy them as small plug in, neon night lights also.

Other Slow Speed Diesels / Re: Still at work, original 6 hp Bamford
« on: May 14, 2023, 08:29:02 PM »
Hi Butch,
My health has been poor so struggling to keep up with the basics.  Not much going on to post here.  I did replace my UV wrecked Dorman plastic radiator overflow tank with an aluminum one to keep the Listeroid 6/1 going.

Its fantastic what you've done to restore those Bamfords!

Best Wishes,

Other Slow Speed Diesels / Still at work, original 6 hp Bamford
« on: May 14, 2023, 07:17:30 PM »
Ive been a fan of Bamfords since 38ac first showed one here many years ago.
I ran into this video that others might enjoy.

General Discussion / Re: Next! 16/2 Lister
« on: May 02, 2023, 03:15:50 AM »
Running a line shaft for an Amish wood shop-  What a lovely application for your 16/2 restoration, Butch. 
Lucky woodshop owner!

General Discussion / Re: Electric car question
« on: February 12, 2023, 08:37:14 PM »
+1 on Lister on free fuel plus solar charging an EV.
I enjoyed the Telsa video. Nuts for the noise levels but lots of fun to watch.  Diesel electric trains have long proven that approach.

Lister Market Place (things for Sale) / Re: Metro 6/1 setup and ready to go
« on: February 07, 2023, 04:59:43 AM »
Very sorry to hear you're having serious health problems, 32Coupe.  I hope you'll get a reprieve. 
Best Wishes,

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