Kubota EL300-E 12v Inverter/Charger

[thomasonw]

how many amps will I be able to draw with the EL300 (4hp)?  around 100?  I'm wondering if there'll be enough power to turn a motor and heat the oil.

I am just now fine tuning that on my system.  I have an EB300 (6hp cont. at 3000rpms per spec sheet) and  am targeting 1790w, or 124A when the charging voltage is at 14.4v  I hope to soon have an EGT connected so I can perhaps fine tune this based on EGT, right now I base overloading on two things:

1) Presence of black smoke (exhaust water in my case)
2) Inability for motor to respond to slight changes in governor position.

The 'formula' I am using  is:
   Watts Allows =  HP * 746 * 40%               

I am assuming an overall system (Alternator, belts, etc) efficiency of 40%.  I will be adjusting this % efficiency number as I learn more.




Based on the above, your 4hp motor comes to:  1200w.  Depending on where you set your fixed voltage regulator, this translates to: 
     Amps = 1200/Vreg-Volts.

So if you set your Voltage Regulator to 14.4v, you would be able to support:
  Amps = 1200 / 14.4  = 83 amps


Still thinking you can capture some heat directly from the motor.  Maybe even run a 2" 'exhaust pipe' through the oil drum to get a bit more out of it???

Hope this helps.

-al-

[wiebe]

take the muffler up in heating the wvo seems simpler than take heat from the cooling system .

[JVD]

Thanks for the math Al.


I tried to test the alternator by sending the current to either of the exposed posts up top... no luck.  I'm going to pull it and look for a replacement.  I'd like to get one the same frame size as the motor is already bracketed and belted.


I'm still working on some simple heat exchanger to heat the WVO.   My ideas ideas are:

Coolant:
To modify the radiator cap so it has a fitting for a hose, and plug the overflow.   Add a FPHE or a coil running though the WVO.   Before the heat exchanger add a pressure release valve set at ~14lbs (what i assume the radiator cap is).   I'm wondering if natural convection would circulate the coolant though the FPHE.  The WVO will already be pumped to run the centrifuge.  I'd like to use a FPHE rather than a coil in the WVO, because i don't want the copper sitting in the WVO for long periods of time. 

Exhaust: Coil copper pipe around the muffler, or clamp a small radiator to the side of the muffler.  Bolt of these don't seem to be very efficient.  I'd like to avoid running the exhaust though the WVO directly as this seems dangerous to me.



The electric motor will use ~500w.. so with 1200w i can still get the oil to temperature electrically.  I'm going to go ahead and put the system together this way and then work towards adding some heating systems.


Next time i pull the motor out i'll snap some photos

[thomasonw]

Thanks for the math Al.


I tried to test the alternator by sending the current to either of the exposed posts up top... no luck.  I'm going to pull it and look for a replacement.  I'd like to get one the same frame size as the motor is already bracketed and belted.


I'm still working on some simple heat exchanger to heat the WVO.   My ideas ideas are:

Coolant:
To modify the radiator cap so it has a fitting for a hose, and plug the overflow.   Add a FPHE or a coil running though the WVO.   Before the heat exchanger add a pressure release valve set at ~14lbs (what i assume the radiator cap is).   I'm wondering if natural convection would circulate the coolant though the FPHE.  The WVO will already be pumped to run the centrifuge.  I'd like to use a FPHE rather than a coil in the WVO, because i don't want the copper sitting in the WVO for long periods of time. 

Exhaust: Coil copper pipe around the muffler, or clamp a small radiator to the side of the muffler.  Bolt of these don't seem to be very efficient.  I'd like to avoid running the exhaust though the WVO directly as this seems dangerous to me.



The electric motor will use ~500w.. so with 1200w i can still get the oil to temperature electrically.  I'm going to go ahead and put the system together this way and then work towards adding some heating systems.


Next time i pull the motor out i'll snap some photos

You know, if there are TWO exposed posts it is likely you need to ground one and send +12v to the other at the same time.  (Or actually, much less then 12v.)   IF you do indeed have two exposed posts you might try using an Ohm meter to see if they are connected (I think a field should give around 3-4 ohm reading), and no connect to the case.  (So, should show open between either of hte posts and the case, and show a few ohms -like 3-4 between the two posts).  If so, then it sounds like you have a floating field and just need to connect one side to gnd while the other gets power.  Before tossing it you might try grounding one side and BREIFLY toughing the other side to +12 and see if you get any current out.  But only do it for a very short time, as full field can quickly cause the alternator to put out tons of power...


And a wide idea:    IF all you are really doing is driving a DC motor and a heating element, then I would say perhaps you do not need to be very precise on voltage regulation.  Assuming you can find out where the field connections are, perhaps just using a large variable resister will be all you need to regulate things as well as adjust the load on the Kubota.  But if you are also recharging a battery, using only a resister can be risky - if one gets side tracked and leaves it unattended for even a short time...

On the heat exchangers, I think there are other posts in here about doing exhaust exchangers.  On the main water, again assuming you are going to only be using this while processing, then I would say:  make a plate to replace the radiator enterally - you want to get as much heat as possibly into the processing tank, not dump any of into the air.  Put a couple of fittings on it to pipe coolant in and out, run those pipes through your barrel perhaps with a small circulation pump.  Place an expansion tank up high - if you keep the temps down low you might even be able to get away without a radiator cap, just keep the whole system unpressured.  But I also know one can get remote expansion tanks with radiator caps on them as well...   OR, make another plate to put on the bottom of the removed radiator.  Replace the existing mechanical fan with a 12v computer one.  Mount a 200o thermostat switch back on the motor and use that to control the fan.  Then mount the radiator somewhere in the return path from you processing tank.  That way you will not be sending much heat into the air, but if the engine does start to overheat the fan will come on and cool the engine down.


It seems a lot is dependent on how you are looking to use this, but it you truly are only going to run it while processing, and are not looking to recharge a battery, you could really make things simple...

-al-

[bschwartz]

....Or to really throw a (probably not too smart) idea out there.....

Could you remove the radiator, install a plate, and instead of using water as the engine coolant, use the WVO circulating directly through the engine?  A small circulating pump to push the WVO through the engine into the processing tank, then the larger motor for the (I'm assuming) centrifuge? 

That could REALLY pull all the available engine heat directly into your WVO.

[JVD]

I have the alt off, and am going to bring it over to an alternator guy.  I hope to trade him my LN 2500 to get this one up and runnung. 

I think ill start out simple as the motors main use will be wvo filtration, and when i stumble on the right parts ill add on some more intellegent alternator controlling.

I found 2 Cummins EGR coolers at the junkyard.  I think people take them off to get more power.. so the .ew plan is to add one to the end of the exhaust and pump the veggie oil through it.  The exhaust is the perfect size it just needs an adapter welded on.

[thomasonw]

I found 2 Cummins EGR coolers at the junkyard.  I think people take them off to get more power.. so the .ew plan is to add one to the end of the exhaust and pump the veggie oil through it.  The exhaust is the perfect size it just needs an adapter welded on.

Huh - EGR coolers, nice find.     Had no idea about them, looks like a great solution!

-al-

[JVD]

Got the alternator apart, cleaned up the connections, and it worked.  It is internally regulated, and it is a one wire alternator.   Good news it'll provide power to filter my veggie oil... however it's not so good for charging the batteries.

I found a Bosch 136A alternator at the dump, as well as a VW EGR cooler (much better design than the Ford EGR coolers).   The Bosch alternator is externally regulated dual field alternator.  To use a smart regulator I just connect one field to 12v ignition, and the other to the regulator?   

Also where can I find a power curve for this alternator? 

[Dualfuel]

I do off-grid biodiesel. Even a 36 amp SI10 with two starting batteries will keep a 1/3 hp motor pumping cold WVO.
I would consider belting a powersteering pump to the Kubota, and pumping the oil directly with that...then there is nothing sensitive to fail when the oil is too cold or whatever other mishap possiibly happens.
Externally regulated alternators can be controlled in a pinch by attaching a automotive headlight to the field circuit. You don't get the nice topping voltage but it will allow you to vacuum the house while the Kubota powers the inverter.
If the EGR thing is too complicated, simply route the exhaust through a gas-water heater, to heat the oil. They make a pretty cool muffler if you find the one where there is stainless tubing flue tubing coiled in the tank.
And finally, there is always using DC voltage directly to heat the oil...the water tank elements are resisters that don't care how much voltage they have, but...low voltage=low heat.
Anyhow, been down the road you are on. Its a pretty cool lifestyle and I wouldn't go back. Have you thought of solar oil heaters mounted on the bus roof?
Also the best WVO pumps are Vickers Vane hydraulic pumps. Always leave the belt just a bit loose so if you do get some bone or something caught in the pump, the belt just slips. Works like a champ.  And yet one more...look for the motors with the extra out of phase starting circuit, Its like a dc starting circuit, and its real easy on the inverter.
BPJ

[JVD]

yeah, my system will work as it is now.. but we start driving in May, so I'd like to get it dialed in before then.

I've considered belting the PS pump to the Kubota, but i'd like to use an electric pump.  This is so while we're going down the road we can still filter WVO whenever I hook up the trucks alt to the battery bank.  There will also be a hot water heater element right before the centrifuge for this purpose.  I was going to just use the inverter... but perhaps 12v from the battery would be easier on everything.

Thanks for the tip on the pump.  I was going to try to find a hydraulic gear pump. bore out the supply and return, and weld in some bigger pipe.

I have thought of solar heat, but for water, not oil.  

I'm thinking i may just get this alternator on and going using a rheostat...  with a dual field alternator will I wire one full field, and the other to a rheostat?  Another thing that is fairly obnoxious is the belt on that alternator I have on it now slips terribly when i start it up.  

also to run this new alternator, i'll have to change the kubota to a serpentine pulley.   Anyone know of one that will bolt up to the flywheel? 

[thomasonw]

Hello.  Sounds like you have made some progress!

On the Kubota shaft, you can purchase a standard round shaft directly from a Kubota small engine dealer.  The Kubota part #: 19501-8451-0  is a 3.5" long  1-7/16" diameter shaft to which you can then attach any pulley you want.  Other shafts I know of are:
  19501-8451-2   1-1/2" x 3.5" PTO shaft
  14972-8451-2   1-3/16" x 2.17" PTO shaft
  14943-8441-3   46mm x 90mm PTO shaft

On the new Alternator, not sure I understand what a Dual Field alternator is.  I am thinking this means you have a couple of external terminals attached to the Field - so you can connect an external regulator.  If this is true, the two terminals are just the two end of one field.  You would attach one terminal to the regulator, and the other to either +12v or GND depending on if the regulator Drives High or Drives Low (P or N type).  Very flexible alternator, but not Dual Field???   Do you by chance have a part number from this Bosch unit?

[JVD]

Thanks for the shaft info!  that's good news.

I've done some more research on the alternator... here's where I'm at:  The serial on the alternator is: 0 124 525 105.  It's used on 06-09 Dodge Rams, and is externally regulated.   It is a Chrysler alternator, which means the regulator is in the trucks electronic control unit, or computer.   The reg often dies and what people do to replace it is this
(Image thanks to psycobilly64 @ dodgeforum.com).  Under the description of how to do this it says that the one field is receiving 12 volts, while the other is receiving 2-6 based on what the regulator supplies... I'm 95% sure that they are understanding this wrong and all that regulator does is controls the ground, it doesn't send voltage to both fields.  I assume that's what you mean by drives high or drives low?

So I'm also 95% sure that you can control either the field or the ground with a rheostat... and that it will be fairly simple to hook up an advanced voltage regulator.  

I'd still like to get a power curve for the alternator, and then I can size the pulley appropriately.    My guess is the alternator makes 70 amps at 2000RPM, and full output around 6000RPM... The pulley on the alternator is 2", so to get ~90 amps i'd really only want a 4" pulley.    Let me know what y'all think.  Thanks for the help!

Edit: i'm still trying to size the pulley because i'd like to just get the Sterling ProReg.  I was hoping I could use the B which is rated for 90 amps: http://sterling-power-usa.com/proreg-b-12voltadvancedalternatorregulator.aspx.  If my alt is rated for more, but belted for 90 I think i'd be alright.   Thoughts?   

[Dualfuel]

Hi again,
Look, I appreciate everybody on this forum having the patience to read my posts...I like this forum because the people here do a real professional job with their designs and setups. I like to be inspired to keep improving my stuff til it starts to rank a bit higher then "cobble".
That said, I am the "master" of cobble. I've lived on the road  in a bus, or truck for most of my life and know how to make do with anything. So forgive some of my suggestions if they are too crude.
If you want to pump oil and filter it while moving, you will obviously have somebody helping you. Consider a PTO with a hydraulic pump as your pressure source for the road. This setup should be very inexpensive if taken off a discarded single axle dump truck. In fact, these trucks are so worthless these days they are often priced right at or less then scrap value...so you buy it, strip the stuff you need, then sell the remains for a profit.
The picture of the regulator looks remarkably like every dodge external regulator I have ever seen in the 1980s or 1970s....hmmm.
One more bizzare idea is to use the serpentine belt on the flywheel itself. If the flywheel is flat, add a slight bead of belt dressing in the center, to form a small crown, and the belt will stay right there.
I know what you mean about the start up. Thats why I use headlights as the external resister. They only allow the voltage to rise to somethnig like 12.5vdc which limits the amperage drawn by the battery bank. Other wise the alternator smokes the belt...
BPJ

[thomasonw]

Thanks for the shaft info!  that's good news.
... I'm 95% sure that they are understanding this wrong and all that regulator does is controls the ground, it doesn't send voltage to both fields.  I assume that's what you mean by drives high or drives low?

So I'm also 95% sure that you can control either the field or the ground with a rheostat...

I think you are right on both counts.  You could confirm with a simple Ohm meter between the two terminal on the Alternator.  I am GUESSING you should see around 2-4 ohms, but it could be much less...  But hey, I would say you are on the right path!  And you could always mock it up with a rheostat, start slow and see what happens...

Sterling seems to me making some interesting things, I am sure the regulator you pointed out would work fine.  Of course, if all you want to do is bulk charge the batteries - perhaps a fixed (but adjustable via a POT) truck regulator would work as well...  IIRC, I picked one up for around $30, but do not remember where....

And perhaps those Dodge forum folks can help you with the power curve.  But if it is OEM Dodge, that info just might not be available...     

Do you know if the Sterling has a 'belt saver' feature?  Something that will let you 'reduce' the max amps produced?  I know some of the Balmer units do, where you can set it for say 60% duty cycle.  It is how I ran my alternator on my Kubota DC generator before making the integrated regulator / controller.

-al-

[JVD]

I can pick up that regulator for under $100, and if the alternator isn't producing more than 90 amps it should work safely.   It has a slow start feature to limit the belt slip.  If that doesn't work I'll add in a rheostat downstream of the reg to slowly ramp up the current myself.

I can't find any info about alternator output, so i'll just have to go with something.   It's for a Dodge Ram 5.9 which has a 7.25" crank pulley.  Probably idles around 750rpm and highway speeds at 2000rpm.  3.64:1 ratio (alt pulley is 2") so that's 2730-7280rpm at the alternator.  

Most power curves for alternators look like this:

So finding that spot where it produces 90amps is going to be tough.   I'm thinking it'll be somewhere between 3000-4000 RPM or a 3-4" pulley.  Anyone have a source for pulleys with a 35-36mm bore?


Edit: trying to keep this on the cheap side I may buy/salvage this idler pulley:  http://www.summitracing.com/parts/dac-89057/overview/  90MM pulley = 3.5 inches.  The bearing is probably a 6203 so if i can pull it i'll be left with a ~ 40mm bore.   Looks like they come on Ford 7.3 Powerstrokes.