I spoke too soon when I installed my new ST3 head.
When I test ran the unit (unloaded) it was quiet and smooth.
Then I tested it with a balanced 240 volt ac load. Again smooth and quiet.
So I thought all was good.

Well ... today I tested it with a 1200 watt resistive space heater on one leg and only a 75 watt light on the other leg.
The growling and vibration was so bad that I thought something had broken in my system !
Terrible vibration every time I unbalanced the two legs, but just fine when the power is balanced.
A] Is this normal for an ST3 (do they need a balanced load all time) ?
B] Can it be fixed ??

Veggie

Here's some pictures.
The unit is wired for 230 volt and I am loading one leg more than the other when the vibrations and noise occurs.

Hi all,

I just installed a new ST-3 head that I had sitting in a crate for the last 10 years.
The wiring looked good and the windings are copper.
When I gave the system a test run (no load), the unit was surprisingly quiet compared to the 3600 rpm unit that I removed.
No screeching and electrical whining noises which both of my 3600 rpm heads made even when unloaded.

I now need to wire the head into my electrical system as two 120 volt outlets (one from each phase). That part is simple enough.
However, it is doubtful that the 4 open connections on the back of the junction box would pass north American electrical codes, so I'm
looking for ideas and pictures of what other members have done to re-wire, reconnect, or change the basic ST design,
Some people have replaced the metal box with a PVC "Scepter" j-box. Others use the stock metal j-box.

Please let me know what you did with yours, and send pictures if possible.
Here's what mine currently looks like....

<click picture to enlarge>

Does anyone speak (or read) Manderin?
The flywheel on my Changfa 195 has 3 markings.
I would like to know what the markings mean so that I can confirm the injector timing.
The manual says to rotate the engine on the compression cycle until the "mark"  (does not say which mark) lines with the notch in the water hopper and that will equal the required 18 deg. BTC.

Well ... mine has 3 marks, and mine does not have a hopper cooler, it has a factory radiator with no notches or markings. 

I have attached these pictures in case anyone can help identify the rotational degree values of these symbols.

<click on the pictures to enlarge>

Does anyone know what the average efficiency is for the ST style generators when running in the "sweet spot". The ST-3 in particular.
As I understand it, the newer design brushless 3600 rpm heads used on today's "screamers" are about 92%.
I was wondering if the ST heads fall in the same efficiency range.

Veggir

New build almost finished.
A Changfa R175 coupled to a 4kw head.
(Max output is more like 2.5kw)

The unit has an external oil filter which added almost a liter to the oil capacity.
I suspect I can extend oil change intervals with this mod.
Also added is a throttle linear actuator which will allow future automation such as remote start/stop and throttle control.
You can see the actuator open the throttle just before the engine starts.
When the actuator is extended all the way to full stop, it sets the engine at 60hz speed. The max extension (60hz setting) is adjustable via a slotted mount at the back of the linear actuator

The small fuel tank is a temporary installation for testing purposes.
I only ran it for a few seconds because the cooling system has yet to be added.
https://www.youtube.com/watch?v=-k1TiayS5N8

I'm looking for ideas.
I can only heat stored water to 212f, but sand can be heated to to 800 degrees and used as a thermal battery.
I don't want to go as high as 800 yet, but I would like to fill a steel tank (maybe 50 gallon size) an try to heat it to 400f.
Then insulate it just enough to still allow for heat to radiate for X number of hours.

Application: Run the lister for x hours to electrically heat up the sand to 400f.
Observe the system to see how long the system can heat the garage in winter.
Start engine .... heat sand ..... Start engine .... heat sand .....Start engine .... heat sand .....
Automate later.
Power the engine with waste oil.

Problem:
How to electrically heat the sand to 400f ?
Basic water heating elements will probably burn up.
I can provide 2kw to 3kw of electricity at 120 volts or 240 volts.

Any ideas for an electrical device to heat fully heat several hundred pounds of sand ?   

These voltage regulators are available all over EBay and Amazon for anywhere between $10 and $30.
Are they any good?
Are they even necessary?
I would think that sine wave conditioning would be a better product to push for the ST heads.
In any case, If any users found a benefit from installing a solid state AVR on an ST heat, please pipe in.
I have an ST-3 and I'm wondering if I should add an AVR ?

By the way ... what currenty controls the voltage on my ST head ? just the engine rpm?

GB160 AVR Automatic Voltage Regulator for Brush Single Phase ST Alternator
Product description
=================================
Features:
100% brand new and high quality.
GB-160 AVR(Automatic voltage regulator) is applicable to harmonic excitation, 1 phase brush generator.
It is suitable for ST series single phase110/220VACgenerator.
Made with flame retardant and heat resisting material, stable and reliable to use.
High precision, long service life.
Specification:
Voltage regulation rate:;±1.0%
Exciting voltage: 20-100VDC
Shunt current: 10A
Package weight: 274g (approx.)
Package List:
1 * Automatic Voltage Regulator