st generator head

berrybus · March 29, 2010, 07:02:34 PM

i have a st generator that has set for 2 yrs. it wont put out any power. i read something about recharging the thing with a 12 volt battrie but cant seam to get it to work. any sugestions?thanks thanks jim.

Sean · March 30, 2010, 01:19:08 AM

A little more information will help. Is "ST" the brand? What model is it? Rating and other specs?

Also, is the motor running and the head spinning, just not making power? Where are you measuring the voltage?

If the generator was working fine before it sat for two years, "flashing the field" is not the most likely issue, which is what I think you are referring to when you say "recharging."

-Sean
http://OurOdyssey.BlogSpot.com

berrybus · March 30, 2010, 06:57:25 PM

this is a china made generator head. its a 15kw direct drive. i cant get any voltage reading on any wiring . i have tried to figure out how to flash the thing but every thing i read dosent give enough information on how to do it in detail. its strange how it worked before.thanks jim.

Lin · March 30, 2010, 08:43:22 PM

Does it have a reset button or fuse somewhere?

Sean · March 30, 2010, 10:54:48 PM

Quote from: berrybus on March 30, 2010, 06:57:25 PM
this is a china made generator head. its a 15kw direct drive. i cant get any voltage reading on any wiring . i have tried to figure out how to flash the thing but every thing i read dosent give enough information on how to do it in detail. its strange how it worked before.

Again, if you are getting no reading at all on a generator that was previously working, it is unlikely to be a residual magnetism issue. Much more likely to be an open circuit someplace.

Without a make, model, or wiring diagram, it will be next to impossible for anyone to help you by typing on a bulletin board. There are too many unknowns (regulation, field excitation, stator wiring, etc. etc.).

It could be as simple as a blown fuse, or maybe a bad transistor in the regulator (if any).

As much information as you can provide here will make things easier. Photos, markings, wiring diagrams, anything.

-Sean
http://OurOdyssey.BlogSpot.com

robertglines1 · March 31, 2010, 06:43:00 AM

I have seen these on E-Bay for around 600 . First I have heard them mentioned here .Has anyone else had experience with them? sounds like Jim has a bad experience.Maybe simple fix:inquiring minds want to know..under ST generator head..have engine would build own gen set..

NeoplanAN440 · March 31, 2010, 09:53:15 AM

hi,
im running a st5 on my Listeroid and a st12 on a Witte.

have you checked allready the brushes and slip rings??
does your head allready have the AVR??
weak point on these is mostly the bridge rectifier!!

check for ac voltage in front of the rectifier and dc voltage going to the brushes!!

NeoplanAN440 · March 31, 2010, 10:28:20 AM

if you have no power on these connections,

remove the two field wires from the rectifier (AC side) and check resistance!!

then you can check the resistance on the rotor (DC side of rectifier)
or remove brushes and check on the slip rings!

if these are all there,i can walk you trough how to energize the rotor field via a battery!!!!

but two years sounds not likely that you need to do that!!!

as said,newer heads have problems with failing AVRs (you dont need that)
or the old design has bad rectifiers!!

i had one failed rectifier in 5 years of running up to 12hrs a day.
i removed the AVR on all my setups,as the st is stable enough as it is!!!

Sean · March 31, 2010, 02:14:06 PM

Does your head look like this?

-Sean
http://OurOdyssey.BlogSpot.com

berrybus · March 31, 2010, 05:28:02 PM

yes the picture is it. thanks jim.

Just Dallas · March 31, 2010, 05:48:44 PM

Removed

Sean · March 31, 2010, 05:54:59 PM

Please open the terminal box and tell me if you have a single jumper/strap between U5 and U6, or a pair of jumpers/straps, one U1-U6, and the other U2-U5. Or also let me know if there is some completely different combination of jumpers.

-Sean
http://OurOdyssey.BlogSpot.com

Sean · March 31, 2010, 05:57:11 PM

Quote from: Now Just Dallas on March 31, 2010, 05:48:44 PM
Is that the Harbor Freight Generator head? It sure looks similar, even though it's a different color.

Dallas, the picture shown is a Dong Feng. I believe HF sells Chicago Electric.

-Sean
http://OurOdyssey.BlogSpot.com

Chopper Scott · March 31, 2010, 06:21:46 PM

I knew a guy named Dong Feng that painted people's faces on a grain of rice. No wait..... it was Hung Lo and he painted your face while you ate rice.... I can't keep em apart. CRS I guess..

Hartley · March 31, 2010, 07:19:52 PM

I have 2 of the ST-10 Generator Heads.

According the the manual that I once had, all you had to do to
re-magnetize the fields was to momentarily hook a 6 or 12 volt battery
across the output leads (120/240) for a second or three.

That would zap some residual magnetism back into the armature.

That's all I have ever had to do even after sitting for a long time.

All ST-Heads are basically a universal design, not much different
between them other than capacity. They all run @ 1800 rpm. They
pretty much are built like a battleship and very heavy.

I bought mine from the same supplier as the Changfa diesel engine
that I have on one. The hardest part is hand cranking a horizontal
diesel engine and still being able to walk 5 feet afterwards.

Dave....