Lister Engine Forum

How to / DIY => Generators => Topic started by: 1958steveflying on November 26, 2008, 10:28:22 AM

Title: 10Kw gen on lister 6/1
Post by: 1958steveflying on November 26, 2008, 10:28:22 AM
Hi All,
  I am rebuilding a lister 6/1 for my CHP system, my question is the only Generator i can get readily is a 10Kw, whilst i appreciate the engine would only be good for around 3 Kw (and thats all i need) are there any reasons why i shouldn't use this size.

  Thanks Steve
Title: Re: 10Kw gen on lister 6/1
Post by: matt on November 26, 2008, 01:12:09 PM
Hi Steve,

There is a fair bit of discussion on this very topic elsewhere on this forum.

Some say that it is wasting energy spinning a too large generator.
Others say the extra weight gives an added flywheel effect to help smooth the output a little and handle sudden loads a little better.

My conclusion is, if it is the only one you can get and is of acceptible quality don't worry too much and just do it.

At least if you overload it (for your engines capacity) you will not burn out the windings. All that will happen is your Listeroid will smoke and slow right down. However , this loss of Hz and voltage may cause havok for items being powered off it - you will need to check this.

Others are more expert on this issue than I.
 
If you stop an engine with an ST type generator under load, it may lose its residual magnetism (which can be rectified with a car battery connected to the windings in the right way).

All the best for your CHP project!!

Matt
Title: Re: 10Kw gen on lister 6/1
Post by: rcavictim on November 26, 2008, 01:14:47 PM
Aside from possibly seeing a slight decrease in total electrical output (compared to spinning a 3 or 5 kW head)because slightly more engine power is used up overcoming the extra windage losses of a larger genset head, I can think of no reason not to go with the 10 kW head.
Title: Re: 10Kw gen on lister 6/1
Post by: ronmar on November 26, 2008, 03:13:42 PM
Won't be as electrically efficient as the generator is way below it's rateing.  As mentioned, windage losses will also whittle ayay at efficiency.  A larger spinning mass can help with smoothing things out, but this mass is better applied as additional engine flywheel weight/heavier flywheels.  Depending on the generator head, you may also run into drive issues like some have, trying to apply torque in pulses to that large generator rotor mass that is resisting those forces.  This can result in belt chirping and added vibration and torque forces transmitted into the engine mount. 
Title: Re: 10Kw gen on lister 6/1
Post by: 1958steveflying on November 26, 2008, 05:39:12 PM
 ;D
  Thanks for all your replies,  At the moment its looking like my best option as right now i don't have any others lined up. At least it means if ever i need more power i can just upgrade the engine. My next issue will be the drive system, my lister has the plain flywheels. What would you all advise.
 
   Thanks again Steve
Title: Re: 10Kw gen on lister 6/1
Post by: ronmar on November 26, 2008, 06:34:35 PM
A serpentine belt runs great on the plain flywheels.  The micro v points are flat, so it runs like a flat belt on the engine flywheel face.  You also have a lot of contact area around the circumference of the large engine flywheel.  Plenty of contact to carry 3-4KW of generator load.    You will need a micro v grooved pully for the generator end as it's smaller diameter(8.25" to get 1800 RPM from a 24" 650 RPM 6/1 flywheel) will need the additional contact that the groves provide to transfer the power.

You might also be able to get away with a standard multi groove pully with the belts also run around the engine flywheel circumference and only the inner flat of the belt in contact.  Balancing tension on multiple belts is always problematic...
Title: Re: 10Kw gen on lister 6/1
Post by: Tom on November 26, 2008, 06:56:34 PM
I'm real happy with my serp belt system. It has almost 600 hours on it with no problems. And since mine is on the flywheel under the fuel tank it sees a bit of contamination and still no slippage.
Title: Re: 10Kw gen on lister 6/1
Post by: 1958steveflying on December 04, 2008, 07:13:45 PM
Ronmar/Tom, thanks for that, i will need 1500 rpm so 10 inch pulley is what i will be looking for.
  Steve
Title: Re: 10Kw gen on lister 6/1
Post by: 1958steveflying on December 07, 2008, 06:06:30 PM
Well i am very happy after a nice 320 mile round trip to collect the 10 Kw St generator from Pete at listerclones.co.uk today. A perfect transaction and a real nice guy to deal with. Now i have to source a 10 inch serpentine pulley and belt. Any info for these in the Uk would be great. Also does anyone have this setup and know the length belt that is used?

  steve

Title: Re: 10Kw gen on lister 6/1
Post by: oliver90owner on December 07, 2008, 09:53:00 PM
Didn't Listerclones have a supply or supplier?  Bit of a missed trick there, from his point of business view.

Belt will depend on your set-up, like the distance between engine and generator, but a bit of string will give you a good indication.  The belt/bearing/ pulley suppliers should be able to furnish you with the standard sizes of belt available.  Or google serp belts and pulleys, and go from there.

Me?  I reularly use Anglian Bearings in Peterborough for most belts and bearings I need.  They also stock, or can source, pulleys etc.  You local supplier will be in the yellow pages, I would have thought.

Regards, RAB
Title: Re: 10Kw gen on lister 6/1
Post by: adhall on December 07, 2008, 09:59:58 PM
Steve:

Regarding belt length:
Here is a link to a online calculator that will give you a belt length given the pitch diameters of the pulleys and the center distance between the shafts:

http://www.gizmology.net/pulleysbelts.htm

Of course, I can't guarantee the results, but I can say that I checked this calculation against my layout and was happy with the number I got.

Best regards,
Andy Hall
Title: Re: 10Kw gen on lister 6/1
Post by: 1958steveflying on December 07, 2008, 10:08:44 PM
Rab, thanks for that, Peter did give me a couple of links but doesn't supply and i have several to contact via Google searching etc, i posted the question on here just in case someone had a good supplier they could recommend from personal experience.
  Andy Cheers, that is a very helpful link.
  Steve
Title: Re: 10Kw gen on lister 6/1
Post by: RhodesRoundtable on December 07, 2008, 10:58:04 PM
Great link adhall

Any opinions on the Chicago 10KW 3600 rpm gen head quality? It appears it would be unsuited to 6/1 8/1 lister pair-up
2 pole rated 16hp
http://www.harborfreight.com/manuals/45000-45999/45416.pdf
Title: Re: 10Kw gen on lister 6/1
Post by: matt on December 07, 2008, 11:48:25 PM
Quote
Any opinions on the Chicago 10KW 3600 rpm gen head quality? It appears it would be unsuited to 6/1 8/1 lister pair-up
2 pole rated 16hp
http://www.harborfreight.com/manuals/45000-45999/45416.pdf

It would be ok for listeroid use. You just need to get the right pulley diameter on the gen to get the right gen rpm.

I suggest you start a new thread for this change of topic.

regards,
Matt
Title: Re: 10Kw gen on lister 6/1
Post by: matt on December 07, 2008, 11:57:11 PM
Quote
Well i am very happy after a nice 320 mile round trip to collect the 10 Kw St generator from Pete at listerclones.co.uk today. A perfect transaction and a real nice guy to deal with. Now i have to source a 10 inch serpentine pulley and belt. Any info for these in the Uk would be great. Also does anyone have this setup and know the length belt that is used?

  steve

Try here....

http://www.stationaryengineparts.com/

This guy in the UK has the largest range of "Listeroid" pulleys I have found anywhere on the net.
He will definately know the answers to any questions you may have regarding the belt length.

Let us know how you go.

regards,
matt
Title: Re: 10Kw gen on lister 6/1
Post by: RhodesRoundtable on December 08, 2008, 01:32:36 AM
matt,
not to be argumentative, but after consideration I concluded my question and input were pertinent to the thread. 1958steve is dealing with availability of a gen-head (specifically 10Kw). Therefore, it seems not at all like a change of topic. I would, however, like to adhere to forum etiquette and not step on the toes of veterans. Any agree it was not closely enough related, please let me know.

In any event, thanks for the link though matt.   
Title: Re: 10Kw gen on lister 6/1
Post by: matt on December 08, 2008, 12:40:37 PM
Hi Obfuscation,

I didn't mean to come across authoratative. Sorry if I was.

I suggested a new thread because the Chicago Gen Head you mentioned is an interesting alternative to the ST, and if it had its own thread it would attract more attention and then the responces would be collated in the thread. This facilitates easier later recall when all the info is together.

I have seen this generator many times on the net under many different brand names, and I am curious as to what these are like in comparison to our beloved ST Gen Heads.

How much were they asking for it?

regards,
Matt
Title: Re: 10Kw gen on lister 6/1
Post by: Tom on December 08, 2008, 05:19:05 PM
The harbor freight head, being a 2 pole 3600 rpm unit, would require a 4" pulley that might not have sufficient to surface area to handle the load. And due to the much higher ratio needed to get the necessary rpm's needed is much more likely to flicker worse than a 4 pole head. That said some vendors are selling similar lash ups, but I don't believe we have had any comments from an actual user.
Title: Re: 10Kw gen on lister 6/1
Post by: RhodesRoundtable on December 08, 2008, 08:23:47 PM
Fair enough matt, thanks for the communication.
The current price is $320 in store no shipping (I guess STs are about $400)
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=45416
They specify peak performance at 20HP.
HF and Northern Tool have been carrying these units for years and are probably the source for many net offers. I have seen them for around $289 last year. Also, they just sent me a 25% off coupon (usually 10%) that I let got to waste ($80 off that item for instance). If you are not familiar with harbor freight, they have very inexpensive tools, but they are cheap. China made really cheap stuff. One Note: There are 2 HF web sites http://www.harborfreight.com/
http://www.harborfreightusa.com/ (check the "see our current add on the left") They are, I'm told, independent and the former will almost always have higher prices. Below is an expansion on Tom's point about the 4" pulley and transmission loss problems that may be useful (accurate?). HF generator rpm requirements and drive ratio:
"A couple things to think about, 20hp @3600 rpm is the requirement to run it at full power (7200w). As for your setup, ie. 7 to one or 3 to 1, the hp requirements will change. Because you are stepping up, with 7 to 1 you need something like 140hp PTO hp to produce 7200w (60hp at 3 to 1). Likewise I would figure 20hp stepped up 7-1 would only produce something like 1000w before the tractor stalls. 20hp/7=3hp at gen, (6hp @ 3-1 ratio) figuring (7200w/20hp=360w per hp) You would be looken at 1080w and 2100w respectively. I am sure these are not exact figures and it does not mean it won't work. But if you are want 7200w you need the hp to get it (ie.. PTO hp x step up or an gen that will work at lower rpms). Regulation is another story and as stated in previous post, could be a real problem if your gov is not up to snuff. A miller 225 welder fit my needs just right at 7500w. But it has its own 20 hp twine cyl engine and internal reg. Good luck."

Best
Regards,
obfu
Title: Re: 10Kw gen on lister 6/1
Post by: SteveU. on December 08, 2008, 09:17:07 PM
Sorry, your quoted source for the ratio change requiring higher HP to produce the same WATTS doesn't make sense. I'll leave that convincing up to others.

15-1800 versus 3600RPM has been debated many times.
Basicly you WILL never get more than you are willing to pay for. Two pole is almost always nonservicable throw-a-away. Four pole is servicable; give to your grand children. Your choice.
One factor I've never seen discussed:  noise.

My gen head was availabe as both 2 pole/3600 and 4pole/15-1800RPM.
The four pole in a full 15db quieter.  That is huge.
My set up will be open mounted in my shop as a power and space heat source. With a slow soothing proven quietable Lister/iod driving. Life in the slow low lane.
I have too many 3600-13000RPM  fast lane screamers already.

All my own opinions
SteveU.
Title: Re: 10Kw gen on lister 6/1
Post by: rcavictim on December 08, 2008, 09:32:19 PM
Sorry, your quoted source for the ratio change requiring higher HP to produce the same WATTS doesn't make sense. I'll leave that convincing up to others.

15-1800 versus 3600RPM has been debated many times.
Basicly you WILL never get more than you are willing to pay for. Two pole is almost always nonservicable throw-a-away. Four pole is servicable; give to your grand children. Your choice.
One factor I've never seen discussed:  noise.

My gen head was availabe as both 2 pole/3600 and 4pole/15-1800RPM.
The four pole in a full 15db quieter.  That is huge.
My set up will be open mounted in my shop as a power and space heat source. With a slow soothing proven quietable Lister/iod driving. Life in the slow low lane.
I have too many 3600-13000RPM  fast lane screamers already.

All my own opinions
SteveU.

Steve makes some good points about the RPM, longevity, serviceability, etc.  3600 RPM is good for intermittent use, throw away kitchen blenders.
Title: Re: 10Kw gen on lister 6/1
Post by: oliver90owner on December 08, 2008, 11:05:34 PM
Being as this has not really been addressed in this thread:

A couple things to think about, 20hp @3600 rpm is the requirement to run it at full power (7200w). As for your setup, ie. 7 to one or 3 to 1, the hp requirements will change. Because you are stepping up, with 7 to 1 you need something like 140hp PTO hp to produce 7200w (60hp at 3 to 1).

Put straight.  Pure and utter poppycock!  Sorry but you need to go back to the text books and basic mechanics. :)

Hp is a rate of doing work (about 750Watts or 750 Joules of energy per second). 7 times the energy would mean that 6 times the original work done would be lost in the process?  As heat?  I think not.  In any instance.

The torque would certainly change , which is a function of speed and power, but the rate of work will not change.  The losses will be in transferring the energy from a low speed shaft to a higher speed shaft - there will always be friction losses.

Losses in tight arcs with belts are well documented - that is why they use cut-away belts (to reduce the compressive forces as the belt is turned in a tight arc).  You may notice that a belt will run hot warm due to the friction in the sheave and the flexing of the material.  This is the main loss in transmission power for these systems.  It does not really make a lot of difference whether the small pulley is driving or driven.

The general rule of thumb we use is 2 horse power per 1 kW electrical output.  This works for the normal run-of-the-mill set-ups we find in most places. 

This one recommends 20HP for 7.2kW or near 2.8Hp per kW. ! >:( That would seem to indicate a poor efficiency performance of the generator and probably reflects high copper losses (heat lost in the windings due to I2R and Ohms Law - due to skimping on the winding wire (cross sectional area).  More heat losses then means more cooling required and so leads to a larger fan and consequent power losses along with increased noise levels.  Also increases the likliehood of a burn out. It also reduces any transient overload ability that is useful for starting motor loads.

SteveU is about right re the quality and longevity.

Certainly for anyone running any appreciable hours, a 35% increase in fuel costs is a convincing argument for paying extra and recouping that extra capital cost while still having a serviceable unit at the end of the period, or the then continuing lower running costs.  A balance of short term gains over long term losses.  That unit appears to be little better than automotive alternator generators which are around 50% efficient (and efficiency falls as they get hotter)

Please imagine a step-up gearbox.  It would not use seven times the power to achieve its rated output.  It would soon glow red hot!!  Many tractor driven generators use a 3:1 increase in speed and some use 6:1.

Hope this does not deter you from posting but you do need to understand the difference between torque, power, energy, etc.

Regards, RAB
Title: Re: 10Kw gen on lister 6/1
Post by: RhodesRoundtable on December 09, 2008, 02:49:57 AM
Well, I guess that sets that straight!
Thanks Oliver
Evidently I didn't give enough credit to where I took this from, hence the peren (accurate?)
It sounded off, that is one reason I put it out there. I figured there could be something in tractor PTO's that I was clueless about. I See it failed your guys test. "poppycock! "  ;D
I did put it in quotes but I should have tagged the link
Post by Errin OH
http://www.ytmag.com/cgi-bin/viewit.cgi?bd=ttalk&th=326232

I appreciate straight talk even when the straight/crooked talkin is completely wrong, at least it is honest. Apparently no one was there to set this guy right, as I'm lucky enough to have here.
I know very little about this kind of stuff comparatively, and less about text books and basic mechanics. A somewhat light green, if you will. Most everything I know about this sort of thing is self taught, so I appreciate the expertise I have especially noted on this forum.
cheers

Title: Re: 10Kw gen on lister 6/1
Post by: lowspeedlife on December 30, 2008, 01:14:13 AM
I followed that link & it appears that someone did inform errin of his computational errors way back in febuary 2003, our very own RAB !! although he didn't use the word poppycock !!

     scott r.