Micro CoGen.

Quote from: pekkap on December 09, 2012, 09:14:06 AM
Hello!

Winter is getting to be present here in finland. Just started changfa at -10C (14F i guess..). Hand cranking was too heavy so i used electric start. Started but not easily.

What kind oil you use in winter conditions? And how cold is it possible to start changa without glow plugs? Is there some fluids for diesel fuels that helps cold starting? I use cheapest 10W-30 and it is pretty hard stuff in -10C..

Here is what I use in this thread, do an internet search for "charcloth" to see how it's made and give it a try.

http://www.microcogen.info/index.php?topic=881.msg10868#msg10868

I cut the slip-on lugs off and replaced them with #8 ring lugs and screws/nuts with some short sections of heat shrink tubing over the wire to insulators of the lugs.  Just added insurance to allow for vibration.  The brass slip-on lugs just do not maintain tension and are brittle.

Main thing is good airflow across the diode package heat sink to keep things cool.

I am assuming you have U3,U4 bridged together.  220-230V available at U1,U2.

You have a 115v recept. across U1 to U3/U4.
You have a 115v recept. across U2 to U3/U4.

Are the voltage measurements approximately equal between U1 to U3/U4 and U2 to U3/U4
no load?

*U3,U4 become floating neutral, not bonded to chassis ground or also called an ungrounded centertap.  The neutral side (white wire) of your house receptable is "grounded" neutral, bonded in panel box.
Making contact with floating neutrals can be lethal, as you may be grounded and become a conductor to ground.  Just a warning.

Which connection under load makes the noise?  U1 or U2?

Have you Ohmed U1 to U3 and U2 to U4 unconnected to posts?

Are the readings similiar?

That's it for now.

Nice job on the radiator adapter plate!  BTW: did you install the cold water return
dip tube under your plate?  Mentioned this just in case.

If you decide to add the T-stat you can buy a 1" dielectric plumbing
union and a standard NAPA termostat will seal inside it between the
two halves.

I am almost tempted to redo these connections by getting #18 aluminum wire
and connecting the pole pieces with compression rings at the joints.  The solder
alloys and dielectric corrosion potential between those metals doesn't give me
much confidence either.

But then I'm still left with the problem the slip-ring connections are copper...geez.
Best I can hope to do is make a mechanical joint there as well.

My last option would be to take all four pole pieces in to the motor shop and have
them wound with copper.  So far I've put back in $180 in this head by getting stator
dipped and baked, new bearings and metal fan.

Leave it to the Lamers at Tawasi  to assemble their heads with mixed metals.
Again if anyone ever ships you that brand of gen head send it back!

Thanks for your comments.

I believe I've used a few shots from spray can of carb/choke cleaner, then finished
off with BG injector cleaner and green pad. Single edge blade can help on the stubborn
areas. Remember approximately the number of turns on your injector adjustment screw
if your tearing it down.  It's been a while since I did it on a Changfa mech. injector.

Quote from: Wizard on April 30, 2010, 12:35:12 PM
Another tip is get extremely fine sandpaper and high temp oil.  Oil coat wire and sandpaper, sand and don't clean off the oil on the aluminum.  Solder through the oil film.

Cheers, Wizard

Interesting, haven't heard about that one.  I ended up rosin-fluxing the pretinned copper stranded to each
aluminum lead with 60/40 and then sleeved it all with heat-shrink.  I sanded clean the aluminum wire before soldering.

Pulled reasonably hard on the joints but they seemed to hold.  Each pole measures 7.4 ohms at the new leads.

Will also be adding a 5A slow-blo in the field circuit.

Well I able to get my local rewinder to change their mind about ST heads.  They got out
of generator market years and ago only rewound motors and new sales.

Unfortunately this particular head (Tawasi) used aluminum wire in their windings.  Ended
up getting the stator windings clear expoxied and baked.  They also polished their
stator laminations in the bore.  Picked up a can of Vanguard Red dielectric paint Class F,
looked like Glyptal to me.  Painted my rotor field coils with that.

Wasn't easy soldering the tinned stranded copper wire extensions to the aluminum pole wires.
Sanded the ends and rosin fluxed then covered the splice with heat shrink.  Waiting for my new
metal fan from Tom Osborn to complete the reassembly.

If these windings ever go then will have then rewound with copper.  The motor tech said he could
do that and might possibly have to adjust the number of turns depending on the change from
metric wire  to awg.

Costco was carrying Kill-A-Watts when I was there in March.

Red goes to keyswitch (+) to battery +

Ohm the green wires and determine which one is regulator
case ground.

The other two greens, one goes to COM and the other to "A" terminal for
the battery charging alternator.

"B" terminal can be switched to low/high charge application.  This is how I
interpret the drawings.

Here's some pix.

Any opinions on the use of synthetic or semi-synthetic type oils in the Changfa engines.  My main
concern is seal compatibility.  Not sure if their use would cause premature leakage.  For now I have
only 12 hours on my engine and that is using Rotella.

Quote from: vdubnut62 on April 27, 2010, 06:19:33 PM
Nice! I want to do something like that when I get my round tuit.
Hey Oilcan, is that plug in the top of the head where the punk goes for cold weather starting?
Ron

Actually, I pack the start plug with "charcloth" and it glows and self ignites as low temperature.  The
manual says to heat it with a torch but by the time you screw it back in it's kinda futile.  What few
low temperature starts I've done in Colorado with it the charcloth worked.  Making your own charcloth
is easy.  Keep it in a well-sealed container after it's made to keep humidity away.

You raise a good point about punk...I haven't given that a try.

Quote from: WGB on March 29, 2010, 11:24:55 AM
Anyone pull a radiator off a ChangFa type engine and put on a hopper?
If so can you give me some input?
Thanks

Take a look at my pix I posted yesterday in ST_STC Generator section of this forum.
See "OilCan's Gen Shack".  I made an adapter plate and ran coolant lines out to an
outside Honda zero pressure radiator.  Fitted a plumbing dielectric union to house the
NAPA 295 thermostat.

Quote from: rcavictim on April 26, 2010, 07:15:33 PM
Perfect!  BTW, that radiator outdoors is contributing to global warming. 

Yeah, I feel real bad about that when it's -8 in Colorado.

Har!

Never saw a part I didn't want...put me down!