Pdf regen on l3901

[Jy durocher]

My kubota 2015 l3901 just passed 400h. It goes into regen every 18-20 h. It drive me nut. I like this tractor a lot but hate the regen stuff.
Is 20 regen normal?

 

[85Hokie]

How is the tractor operating during those 20 hours? low RPM's or high RPM's?
If low RPMs - I would run it up and see if there is difference.

 

[Henro]

My kubota 2015 l3901 just passed 400h. It goes into regen every 18-20 h. It drive me nut. I like this tractor a lot but hate the regen stuff.
Is 20 regen normal?

18~20 hours? No regen here so no clue, but it doesn’t sound too excessive.

Did you mean minutes? Now THAT WOULD drive me nuts…

 

[Jy durocher]

Every 20 hours.
I do run the tractor at 1800 rpm most of the time. When i am on the backhoe: rpm at 2200

 

[85Hokie]

Every 20 hours.
I do run the tractor at 1800 rpm most of the time. When i am on the backhoe: rpm at 2200

For the next 20 hours - or hopefully it will be more, run it at 2400 all the way around.
That 2400 is not even max RPM according to the data.

The problem with Tier IV is that you have to get the screen at the exhaust really hot to burn those particulates off. You will not hurt the engine running it in that range.

 

[MapleLeafFarmer]

My kubota 2015 l3901 just passed 400h. It goes into regen every 18-20 h. It drive me nut. I like this tractor a lot but hate the regen stuff.
Is 20 regen normal?

Its about normal given your decision to only run at 1800 rpm per statement below. Why do you want to operate rpm's below designed operating range?

Run it a little hotter (2,100) and your duration between regens will go up and in the long run your diesel will thank you.

Also could switch to premium diesel, seasonally suitable and keep it fresh (and no bio diesel) and all will help you extend if this is important.

wondering why it drives you nuts though??? it happens in the back ground, you can keep working while it regens and on our 3301 the average operator can't even notice its happening.

FWIW... your not operating your tractor hot enough / rpm's fast enough like it was designed. Running at only 1,800 is too low for that modern tractor. If you are only working it moderately hard even in summer your tractors computer is probably going to scream at you with a bright flashing light on your dash trying to tell you to up your RPM's as you be not running your tractor hot / fast enough. Following the tractors instructions and your duration should increase

 

[TheOldHokie]

Every 20 hours.
I do run the tractor at 1800 rpm most of the time. When i am on the backhoe: rpm at 2200

My experience is close to 40 hours between regens if you keep engine RPM in the 2200+ range and avoid short run times.That allows the DPF to clean itself without help from the ECU.

Running at 1800 RPM or short periods causes soot to accumulate in the DPF and the ECU has to take over.

Dan

 

[Jy durocher]

Thx you all for your advise.
I didn't realize it was better to run it at 2200-2400 all the time. Will do. It all make sense now.

 

[mcmxi]

Thx you all for your advise.
I didn't realize it was better to run it at 2200-2400 all the time. Will do. It all make sense now.

I use the MX all winter long to push and blow snow and rarely does the tractor do a regen. I start out blowing downhill at 2,200 rpm for about 200 yards, then push snow on the lower driveway at 2,000 rpm for another 200 yards. I turn around at the bottom and then come back up the lower driveway at 2,400 rpm (it's fairly steep), then rinse & repeat. Coming back up the driveway puts the tractor under a good load and the DPF is hottest in those moments. When I'm clearing the parking areas in front of the house and garage I'm running at 2,200 rpm.

I putter around at 2,000 rpm and limit "idling" at 1,300 rpm as much as possible. You definitely want to get the DPF hot, but in my experience you don't need to run the engine constantly in the 2,200 to 2,400 rpm range. This strategy has worked well for me and I see significant fuel savings too.

 

[lugbolt]

2400? When I had one, it was at wide open throttle all the time. I don't think it had a regen but about every 50 hours. Put some earplugs in.

 

[fried1765]

For the next 20 hours - or hopefully it will be more, run it at 2400 all the way around.
That 2400 is not even max RPM according to the data.

The problem with Tier IV is that you have to get the screen at the exhaust really hot to burn those particulates off. You will not hurt the engine running it in that range.

So... help me understand this....
Pistons/rods/crank, etc., running at 1800 RPM (or less) wear ("not hurt") at exactly the same rate as those running at 2400 RPM?

 

[85Hokie]

Has nothing to do with that!

The fact that a computer is regulating the RPM to burn off those particulates at the time when the filter is clogged - then why not burn them off with using the machine as it WAS intended.

We have to get past the fact that running a machine at idle is a "good" thing - a diesel is meant to be run at a pump level RPM.

I tell you what - go to a commercial building site and watch them run a $500,000 track hoe, I'll bet it never sees idle, EVER !!! I have been in that situation and got my ass chewed for babying the machine.

A Tier IV is a PITA - putting around at high idle it makes it a jet propelled bitch - having the computer regen it every 20 hours, you have to be kidding me!

 

[TheOldHokie]

So... help me understand this....
Pistons/rods/crank, etc., running at 1800 RPM (or less) wear ("not hurt") at exactly the same rate as those running at 2400 RPM?

Hard to measure that in isolation. The facts on the ground are it ts a common rail diesel with DPF, governed max engine speed of 2700 RPM, and designed to run all day at 540 PTO speed (2400 engine RPM).

So do you think running at 1800 RPM with active regens every 20 hours results in more or less engine wear than running at 2400 PTO speed and halving the number of active regens?

It would be an interesting engine stand test. I would be inclined to bet on fewer regens reducing engine deposits and wear = longer engine life.

Dan

 

[fried1765]

Hard to measure that in isolation. The facts on the ground are it ts a common rail diesel with DPF, governed max engine speed of 2700 RPM, and designed to run all day at 540 PTO speed (2400 engine RPM).

So do you think running at 1800 RPM with active regens every 20 hours results in more or less engine wear than running at 2400 PTO speed and halving the number of active regens?

It would be an interesting engine stand test. I would be inclined to bet on fewer regens reducing engine deposits and wear = longer engine life.

Dan

I think you missed my point!
I don't care one iota about "regens", I will never have one.
Your comment seems to indicate that you believe that any engine run at 2400 RPM will last just as long as the same one run at 1800 RPM.
I DO NOT believe that!

 

[85Hokie]

I DO NOT believe that!

Ok - you have never worked commerical construction that I know of - you have never operated a half mil dollar machine - you believe all you want. Easter bunny, santa claus - unicorns, I care not. I just know that limping a diesel around does IT NO good!

KUBOTA designed it to run - NO WHERE IN THE manual does it say dperate at high idle - other than to warm the machine up!!!

Remember something - you do you, and the rest of us will do ............... US!

 

[fried1765]

Ok - you have never worked commerical construction that I know of - you have never operated a half mil dollar machine - you believe all you want. Easter bunny, santa claus - unicorns, I care not. I just know that limping a diesel around does IT NO good!

KUBOTA designed it to run - NO WHERE IN THE manual does it say dperate at high idle - other than to warm the machine up!!!

Remember something - you do you, and the rest of us will do ............... US!

You are correct,.....sort of...
But I have operated a 200 million dollar machine ,....for thousands of hours, though I do not see the relevance.

Onan has "limped" their 1800 RPM diesel generators around for MANY years
Lister-petter diesels run even slower......because it is bad for them ????.
It is a known fact that diesels in general, operate most efficiently at or below, 1800 RPM.
........and they last a long time!

 

[fried1765]

Ok - you have never worked commerical construction that I know of - you have never operated a half mil dollar machine - you believe all you want. Easter bunny, santa claus - unicorns, I care not. I just know that limping a diesel around does IT NO good!

KUBOTA designed it to run - NO WHERE IN THE manual does it say dperate at high idle - other than to warm the machine up!!!

Remember something - you do you, and the rest of us will do ............... US!

Why have you found it necessary to use intimidation, and personal attack?

 

[85Hokie]

You are correct,.....sort of...

It is a known fact that diesels in general, operate most efficiently at, or below, 1800 RPM.

Depending ON the Tier of the engine!!!!!! AND the size and the DESIGN!

All diesel operate in the same "manner" - some are designed to operate at a higher RPM , take the D902, it is in the BX23XX series - it works best at 3,000 PLUS - 3,450 is max rpm.

A Kubota V6108 engine for example has a high RPM of 2200 - but much of it's power come below that RPM.

One engine is screaming to make 23 hp the other makes that before the key is turned!

The OP asked WHY he is regenerating at 20 hours .......... it is because THAT engine needs to get the exhaust temps HOOOT - HOTTER exhaust burns those little bitty particles up and keeps that screen clean. The debate on wear is down a rabbit hole that would need to be looked at in another posting. AND even that debated will have different facts based not so much rpm - but rpm vs load!

 

[Russell King]

Onan HAS to run the 4 pole generator at 1800 RPMS to get the required 60 Hertz power supply out of it.

That is also assuming that the generator was built without any inverter technology involved to condition the output power.

 

[TheOldHokie]

I think you missed my point!
I don't care one iota about "regens", I will never have one.
Your comment seems to indicate that you believe that any engine run at 2400 RPM will last just as long as the same one run at 1800 RPM.
I DO NOT believe that!

I think you are the one missing the point.

We are talking about the operating characteristics of engines equipped with DPF and catalytic converters. What you may or may not ever own is of zero consequence.

A forced regen on those engines runs for 10 plus minutes at WOT and very elevated EGT. Raw fuel is introduced into the exhaust stream to aid in burning off soot and contributes to fuel contamination of the engine oil. The frequency of that process has to be considered in any discussion of comparative service life.

Increasing the operating speed of the engine from 1800 to 2400 RPM is going to add some incremental increase in sliding wear. It also reduces the frequency of active regen by a factor of 2X or more. That reduction in regen cyclez is very significant and could quite easily offset the reduced wear associated with the slower operating speed. Its also important to remember that the higher operating speed improves DPF performance and service life. Like it or not its part of these engines.

I will reiterate - the only way to know how those competing factors balance out would be controlled testing - e.g. an engine test stand or fleet testing.

My gut says the increase in sliding wear associated with an added 600 engine RPM is relatively insignificant compared to the increased wear and contaminatuon associated with overly frequent regens.

Unlike you I own a DPF equipped tractor and I have observed first hand how mildly increasing engine RPM greatly reduces the frquency of active regens. Thats why I generally operate my DPF equipped tractor close to 2400 engine (540 PTO) RPM regardless of the job I am doing.

If you can provide some reliable test data demonstrating I am off base in that belief I would certainly be interested.

Dan