Which gen would you use on the 13 hp cat diesel?

[panaceabeachbum]

I have one of the 13 hp cat/perkins engines coming from surplus center as discussed in the other thread.   https://www.surpluscenter.com/item.asp?Item=28-1726&UID=2009072813274344   


I plan to use one of the Chinese 8kw stamford clones from ebay   , ebay auction number    150342728389. 

The engine makes maximum torque at 2400 rpms , what speed would you gear the engine to run at?   Is there another gen you might choose for this engine? 

specs on the engine

http://www.cat.com/cda/components/securedFile/displaySecuredFileServletJSP?fileId=184036&languageId=7


http://www.perkins.com/cda/files/334130/7/402D-05%20Engine%20PN1812%20May09.pdf?m=97265&x=7

[mobile_bob]

one of utterpowers pm heads would be nice, preferrably the new 6kwatt head
it needs 3600rpm and the engine can deliver the same

that would be a nice clean setup in my opinion

alternatively a niehoff 275amp 24 volt nominal  direct drive would be a nice battery charger

or a pair of 110-555jho presolite/leece nevilles would be really cool to
although they would need belt driven

maybe even an induction generator? that would be cool for grid tie, and with caps as a stand alone in some
applications.

personally i wouldn't mess with an st head, for no other reason that the physical size gets a bit cumbersome.

bob g

[oliver90owner]

stamford clones

While on the subject of Perkins/Cat in another thread, we need to note that the 'stamford clone' part is now 'Cummins clone'.

Seems that everyone owns everyone else .

Regards, RAB

[xyzer]

I picked up a Kubota z482  that has about the same specs as the cat. http://www.nextgenerationpower.com/5kwrad.html. This is what they did. I have had no problems with the configuration ....yet. They have it running at 2800 rpm.  I think I paid $1750.00 for the engine gen setup and built a enclosure for it. It will use about .4gal/hour. Runs good.   
Dave

[Quinnf]

Mebbe I missed it, but one thing I don't see in the specs is how the engine's governed.  If it's variable speed, it might be unsuitable for generator service.  Nice engine, though. 

Quinn

[panaceabeachbum]

The engine is governed and designed for fixed speed operation .

I just got a message back from Perkins and they are reccomending engine speed of 2400-2800 rpm for gen use

[Quinnf]

That makes sense.  Max torque looks to be around 2500 rpm which should also correspond with the lowest specific fuel consumption, though they didn't show that curve on the torque/bhp/RPM plot

Quinn

[mobile_bob]

my recommendation for direct drive 3600rpm operation is based on the likelihood
of the genset running in an intermittent operation as opposed to a 24/7 offgrid situation

if you need to run it long hours, maybe then run it at peak torque, and likely best economy but
the compromise dictates you will get less power and more complexity (belt and pulleys)

personally i don't see the little engine as a competitor to the 6/1 for long term operation, but rather
a strong competitor for short run operation for when the power goes out due to storms

at which time it is likely you will either need or want max output from the genset, which will require the engine
to run at 3600rpm.

it comes down to a good understanding of what your needs are to start with, and then work the engineering to make
the proper choices to fit the need.

bob g

[panaceabeachbum]

Yes short run during hurricane season is my intent , something a little more reliable than the propane powered unit we have currently that my wife can walk over , flip the transfer switch and push a button to be back on line .
 I think its kind of a toss up on the comparison to the listeroid for longevity . I like the lister and am currently searching for a CS  but I can purchase 3 of the little cat deisels for the cost of one Indian built lister of similar out put , current pricing delivered to the door.
The man I spoke with at Perkins stated this engine has a service life of 6000 hours at 3600rpm and should be consdierably longer at 2500 rpm , thats 18000 hours for an out of the box engine (well 3 engines) for the cost of a single listeroid . 

I must mention that my above statement and math  are not meant to stir up a fight over listeroid reliability etc, I really like the lister and as soon as an original pops up I will have one of those in the gen shed also , right next to the other 4 generators that currently occupy the building . This one is just being put together as a push button solution to keep my high maint woman friend happy .

I have a spare PLC that I am going to program so a single push of the button will open the fuel solenoid, pre heat the glow plugs for a set amount of time and then engage the starter for a preset length of time or the engine starts , which ever happens first . The plc can also be set to monitor engine rpm, water temp , oil pressure and just about anything else and then go thru a preset routine depending on the situation/programming

[mobile_bob]

here is an interesting alternative

take your perkins/cat/shibura engine

set it up and run it at progressively slower speeds in an effort to find the lowest speed that it will run
and still do so relatively smoothly, lets say that speed is 1500rpm.

call this speed idle, and set your plc code to match this parameter

drive a pair of hd large frame alternators, such as the 110-555jho for ease use the 24 volt versions
connect the outputs of both altenators in series for 48 volt operation and both fields in parallel so that
a single 24 volt balmar or xantrex controller can regulate and take control of three step charging.

charge a set of golf cart deep cycle batteries 48 volts at about 225amp/hr is sufficient

use an inverter of 5-6 kwatts for perfect sinewave, rock solid 60hz power

now go back to the engine, and particularly the fuel rack
control the rack with a current solenoid with a shunt, using a bias spring
by tailoring this spring and useing the current flowing from the alternator to the batteries
you can alter the position or pull of the solenoid on the fuel rack
low load will pull the fuel rack up off of idle, medium load will pull to approx 1/2 throttle
and full load will pull the rack full open.

it does not need to be highly accurate, because we don't need tight freq control off the alternators
the inverter does that all by itself.

the plc/controller can initiate a startup, run at idle for a predetermined length of time, then close the relay to
trip on the balmar/xantrex which in turn will turn on the field of the alternators, after which time the dc amps delivered by
the alternators to the batteries via the current solenoid which controls engine rpm

now you have an engine that can idle and sip fuel quietly as possible, until there is a load, then it can throttle up
as much as is needed to suit that load, and you have batteries to buffer with and provide power in a black out long enough
to get dressed and go fuel up and do a startup of the genset if need be... or

the plc can be used to automate this process, and not do a startup if the blackout is of a short predetermined length of time
and do a startup if it is longer period of black out.

properly done, finely tuned a system such as i described will compete favorably with a fixed speed listeroid/st genset
in fuel consumption, leaving the question of longevity as the only thing left unanswered.

bob g

[panaceabeachbum]

thats a good Idea,  to this point I had only thought about programming the start up procedure and watching oil fuel and water temp with the plc , but the tought of using it for full engine management and controlling rpm /gen output based on load is a good thought  . I will have to put more thought into that approach as the plc I am using has a lot of unused I/O  and processing ability .

Would you think I should be monitering and responding to load at the inverter or watching batt voltage drop?

[mobile_bob]

i would do both load and battery voltage

battery voltage as a start que

load while the engine is running will keep the rpms in check and also keep the cycling
of the batteries to near nill, which makes them last many times longer.
one less cycle on the batteries today = one more cycle i can expect out of them down the road.

also by using the batteries, and a larger inverter i can support a much larger startup load than would be normal
to support off the engine driven alternator to start with,  and significantly larger short term loads than the engine
or alternator could support on their own.
 the batteries fill in the shortfall of amps from the alternator, only to be put back into the battery over a longer charge time
at the lower rate.

therefore it is possible to support for instance a 10kwatt load for perhaps an hour or more with a 4 kwatt alternator and a battery
bank sized to shore up the difference. so you supply the 10kwatt load for an hour and run the engine for 2.5 hours total (not counting charging inefficiencies) to put all back as should me.

or it is possible to support a 20 kwatt load for a few minutes using the same 4 kwatt alternator, a battery banks matched to the load
and a suitably large inverter to get the job done and then have to run what it takes to put it all back right again.

all the running could be matched to peak efficiency of the engine as well,

bob g
bob g

[panaceabeachbum]

I am liking the thought of this, would be the prius of gensets

[compig]

Really frustrating that I can't get one of these at a reasonable shipping price !!  I'm still waiting for the surplus centre to advise a sea freight price ! The battery charging , inverter route was my plan also.

[roverjohn]

Can someone please explain to me how Bob's idea is a good one?
1.It's crazy complicated.
2.What little fuel you might possibly save during run time is then wasted after the short run as your battery still has to be maintained as it's continuously self discharging.
3.Unless you have access to free Xantrexes, inverters, and forklift batteries it has to cost 3x as much if not more.
4.It probably weighs 10x more.
5.If something breaks in the Xantrex/inverter combo no one but an EE could fix it before the grid comes back up.

If you want to add cost and complication why not add a belt and drive a compressor that could then supply heat or AC/refrigeration which would be practical as it would lessen the gen load. Or add a big truck alt and use it as a welder for storm repairs. I don't want to dog on Bob as his plan could be made to work by someone like NASA, and he seems like a nice guy, but for most of us a plug and play genny would be a safer bet. Especially if your aunt needs power more than you and she lives ten miles away.