Kubota EL300-E 12v Inverter/Charger

[JVD]

I just picked up a Kubota EL300-E(~3hp).  The motor was used on a construction sign to keep the batteries charged up.  It has a Lestek 9150 Alternator belted to it.

I live in a housetruck which has a solar panel, 12v bank, and 1500W inverter.  My plan is to use the Kubota mainly to power inverter, to run my WVO filtration system.   This system consists of a 1/3 hp motor, and the largest hot water heater element the Kubota will support.  I would also like to use the Kubota to charge the batteries when there is no sun.. however our electricity usage when not filtering WVO is very low.

I'm just getting into all of this, so feel free to point out all my errors 

Some questions:
Alternator:
I'm having a hard time finding any information about the Lestek alternator, as the company closed in 2004.  At the moment it's still on bracket.  I'm not sure if it's internally or externally regulated.  Anyone know some more information about this alternator?   I'm pretty sure it'll need to be replaced, but i'm on a tight budget so if i could use it, it would be great.   The model # is 9150 140amps.  I'll open it up and have a look when I get the time.  If i can't use the alternator, i'd like to at least use the bracket on the motor.  What type of mount is it?

If I'm trying to keep it simple should I just use a 14.4V regulator and rely on solar to properly top off the batteries?  Especially considering 95% of usage would be to run the inverter with a large load.  We'd only use it to simply charge the batteries if it was an "emergency".  Perhaps down the line I can add a three stage to also properly charge the battery bank.  (when I do it would also be pretty cool to tie it into the trucks alternator)

I'm thinking 140-160amp alternator 14.4v regulator.  Pulleys sized to output ~90-100Amps at the motors peak.   I'm also debating to add a rheostat or variac to manually limit voltage.  Do you think there will be a problem simply using the motor to limit current?

Any tips or comments are appreciated!

[mike90045]

...... Do you think there will be a problem simply using the motor to limit current?   

None at all, till the day you step away for 5 minutes, that turns into 30 minutes, then it will boil the batteries,
let the air out of all the tires, and put sugar into the gas tank 

[thomasonw]

Hello.  No idea about the Alternator, but I would think it would be like most other alternators.   

When I assembled my Kubota / DC generator I quickly found out it was easy to overload the Kubota, and there was no way I could pull more then say 120A from the alternator w/o seeing black exhaust discharge. I have an EB300 speced at 5HP cont., the EL300 being smaller would be even more of an issue.    So, I think a major consideration here is how to limit the Amps to prevent overloading.   

Selecting an undersized Alternator would work, but you indicate the alternator is 140A.
Under spinning the alternator could work, maybe that is what they are doing?  (How large are the two pulleys?)
Using some type of Amp Limited in the Regulator (in effect a programmable chopper in addition to the Voltage regulator function) will work - and you can find external regulator such as the Balmar ARS-5 or Max-Charge and their 'Belt Load Manager' feature.

I am wondering given that this unit was designed to maintain battery charge perhaps it already has some method designed in.  Have you been able to fire it up and see what voltage it regulates to, and perhaps see how it responds to a large load - say powering a space heater via your inverter?  You might be able to use it as-is, or perhaps with a simple modification if the regulator voltage is set too low - ala if it is set for 13.2v 'Float' Voltage, adding in a couple of diodes to the voltage sensing would bring it up to 14.4vor so..

And I would say if you want to keep it simple, your idea of using it for Bulk and part of Acceptance Charge then letting the Solar Panels finish things up would work fine.  When we run our DC generator we typical keep it going in until the Amps being accepted drop below 60a, then let the Solar Panels finish things up.

And have you considered using the cooling system as a heat source?  Might be simple to set up a thermal siphon arrangement to your WVO processing tank.

Finally:  If you ever want to Pimp-it-out, I have been working on an integrated regulator / throttle controller project for just this type of setup- you can read more here: http://www.microcogen.info/index.php?topic=2941.0  A key feature is actively managing the Amps being delivered as well as the voltage, thereby using all the engine capability at all points of operation.

Best of luck, I think I would 1st try to fire it up and see what it does. You might be very close to already having most, if not everything, you need for a simple setup.

-al-

[JVD]

Al,

Thanks for the reply.

I've fired it up, and I'm not getting anything out of the alternator.  This didn't surprise me however, as the two pins on top of the alternator are empty.  I was going to make a wire to the right pin to see if it's externally excited, and if it will then put out some power...  But when i started reading about all this, I decided to ask a few questions first, as I don't want to fry anything (thinking that if there was an external regulator, and it's been taken off... firing it up without it may burn out the alternator or something else).

I suppose i'll bolt it all back down, add the wire, and test it that way.

I'd really like to avoid buying a new alternator and a $300 controller, so it would be nice if it works. 

JVD

[thomasonw]

Hello.  Well, ya - that sounds like something is missing.  Seems likely that an external regulator was used, too bad it did not come with the unit.

I went to archive.org and there are several captures of the old Lestek company, you might look through them (takes a bit of work as some of the images are missing, but if you look at the links you might be able to find some info).  Here is one example:  http://web.archive.org/web/20040806120340/http://lestek.com/Alternators.htm
http://web.archive.org/web/20040413144358/http://poweralt.com/Installation.htm
http://web.archive.org/web/20040518204358/http://poweralt.com/Reg.&Alt%20trouble.htm
http://web.archive.org/web/20040517103751/http://poweralt.com/J18012V-Install.htm

and more here: http://web.archive.org/web/20040915000000*/http://www.lestek.com

It seems that Lestek was taken over by Pentexx.   http://www.penntexusa.com/dimensions.htm  There might be some old info on their web site as well.

Perhaps if you inspect the two posts you can determine if they are connected directly to the brushes (assuming this is a standard brushed alternator).  It sounds like it is an external regulator- but is good to be careful!

Being you have no regulator, I still think a major issue will be how to limit the total amps produced to keep from overloading the engine.  Perhaps look to see what diameter pulleys are currently being used, they may have set it up for less then MAX RPMs to keep the alternator down on the output curve.   If so, then any standard external regulator would work I think (assuming you use it as described - bulk and let solar finish things up).  But if not, then am thinking you would need some amp reducing feature on a regulator.  I would NOT go with a simple resister, as I suspect things would change too much over the charging time and you risk harming the batteries...

Hope this give you some more ideas.

Best luck,
-al-

[JVD]

thanks for all the research... didn't even think about searching internet archives. 

I have a LN 2500LC... Thinking about pulling it apart and attempting to use that regulator.

I was also considering using the waste heat to heat up the WVO.   The motor is water cooled, but it seems to simply use thermosiphoning to circulate the coolant.  I'm thinking about adding in a heat exchanger right into the top of the radiator.. using the overflow tank from a car with a fully pressurized coolant system.   An exhaust heat exchanger will be a bit more difficult as the exhaust already points directly down below the motor about 5"... The motor will be mounted under my truck, so there's not a whole lot of room to add a exhaust heat exchanger.

[thomasonw]

thanks for all the research... didn't even think about searching internet archives. 

I have a LN 2500LC... Thinking about pulling it apart and attempting to use that regulator.

I was also considering using the waste heat to heat up the WVO.   The motor is water cooled, but it seems to simply use thermosiphoning to circulate the coolant.  I'm thinking about adding in a heat exchanger right into the top of the radiator.. using the overflow tank from a car with a fully pressurized coolant system.   An exhaust heat exchanger will be a bit more difficult as the exhaust already points directly down below the motor about 5"... The motor will be mounted under my truck, so there's not a whole lot of room to add a exhaust heat exchanger.

If I remember correctly, the coolant drain valve on the bottom of the head will take a standard 1/2" MPT fitting.  (Maybe it is 3/8", I tried it once jsut hand tightening to see if I could use it for my coolant tap, but have not hooked anything up yet.)   Perhaps you could get a spacer machined up to sandwich between the existing air radiator on the top, and have a port out the side.  -OR- I have also seen someone punch out what looks like a freeze plug higher in the head (next to the injector) and tap that hole for a 1/2" (3/8"?)  MPT fitting.   

In either case, you could remove the current belt driven fan, replace it with a 12v computer fan (it looks about the same size) connected to a higher temp therm-switch.  Get real fancy and add a gate valve to the thermosyphon ckt to control the amount of heat taken form the engine, and allow the thermostat  / computer fan to be the 'backup' in-case too little heat is extracted.  Heck, if you are height limited you could just remote the radiator, make up a flat alumn plate to bolt to the to of the engine with some MPT fittings in it.  Then make up a like plate for the bottom the radiator and remotely mount it.  Again using a computer fan as needed.


I see no reason why you could not modify the LN 2500LC regulator to work - mostly will eb about modifying the brush posts to accept wires instead.  But I still wonder about how the max Amps are being limited. . .   My guess is they under spin the alternator, maybe at 1/2 its rated RPMs.   What size drive and alternator pulley are currently installed?  That might give some insight.

-al-

[JVD]

another great idea..  I'm looking into how to modify the radiator neck/cap.   I'm away from the motor for another week still, so I can't tell you about the pulley sizes.  I'll let you know as soon as I get back.

Do you know the differences between the EB300 and EL300? 

[thomasonw]

Do you know the differences between the EB300 and EL300? 

My understanding is the EL300 is a lower HP version or the EB..   Maybe 4HP cont vs. 7?

I did fine this posted with the EL300 specs:  http://www.microcogen.info/index.php?topic=2339.0

Looks like they spin it slower: 2,000 RPMs max, where the EB300 runs up to 3,000 IIRC.   I do not know if there are changes to the internal parts (ala the injector, etc), so it might be more then just a different governor stop setting.


-al-

[Henry W]

The EL300 has no counter-ballance shafts so it is limited to 2000 RPM.

The EB300 come in 2 differant speed ratings. (2600 and 3000 RPM)

Some of the E-series engines do not have glowplugs, starter or alternator.

The most sought after E-series engines of the bunch are the EA300-NB1 and the EA330-E3-NB1. They come complete with Radiator, Starter, Glowplugs and Alternator. The speed rating is 3000 RPM.

The EA330-E3-NB1 has a larger bore and peak torque curve comes on at lower RPM's than the EA300-NB1. The EA-330 series can be set up to match any of the load ratings of any of the engines in the E series.

Henry

[thomasonw]

Thank you,  I figured there was  likely more difference then where a set screw was positioned 


Do you by chance know what the difference is between an EA300 and an EB300?  When I purchased my Kubota (E-bay, ex tank-trailer engine) I was told it was an EB-300.  Try and I might I can not locate any markings on the engine, nor any info on EA vs EB. . . .

-al-

[Henry W]

There must be a serial number located on the block someplace. When facing the gearcase cover look at the right/front mounting foot. Sometimes the serial number is stamped on the edge of the foot. I will look at my engine when I get home. I will write some more about possible differances.

Henry

[Henry W]

I did some checking and there should be a serial number on the right front part of the engine mount/foot when facing the gear case.

I found some interesting info that surprised me.

The camshafts are the same on the EL300, EA300 and EA330 engines. I would imagine the EB300 camshaft is also the same but I don't have a part # to prove that it is.

The engine blocks are the same on the EB300, EA300 and EA330 engines. I don't know if the EL300 engine block is the same.

The PTO stubshafts are the same on the EA300 and EA330. They are 1-7/16" in dia. The EB300 stubshafts are different. there are three different SAE styles they are only 24mm in dia.

The injector nozzle piece for the EA300 and EA330 are different. The springs and all other components on the injectors are the same for the EA300 and EA330 engines.

Fuel Injection pumps are the same for the EA300 and EA330. The EB300 Fuel Injection pump is different. I would imagine the EL300 Injector pump is different from the rest.

It looks like the main difference in the in the fuel system in all the E series engines is the calibration of the injector pumps and injectors.



I do know:

The fuel injection timing for the EL300 is 19 deg. Before Top Dead Center.

The fuel injection timing for the EA300 and EA300-N are 21 deg. Before Top Dead Center.

The fuel injection timing for the EA300-NB1 and EB300 are 23 deg. Before Top Dead Center.

The fuel injection timing for the EA330-E3-NB1 is 25.5 deg. Before Top Dead Center.



For now, this is all the info I have on these engines. I will post more when I find them.

Henry

[thomasonw]

There must be a serial number located on the block someplace. When facing the gearcase cover look at the right/front mounting foot. Sometimes the serial number is stamped on the edge of the foot. I will look at my engine when I get home. I will write some more about possible differences.

Henry

Well, of course it was there.  I will swear I had looked SOOO many times before, even when the engine was not assembled into our DC generator.  But alas, it was there, looks like  E??-980990   Thanks.

-al-

[JVD]

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.

Also I don't have any experience with natural convection.  Will thermosiphoning be enough to move the coolant up to a drum full of WVO, and through a copper coil in the WVO?  or would something like this require a pump?