prensel

Member
Hi all,

I recently purchased a nos Aeroparts centre pto kit for my series 2a.
Also have I purchased a 25kVA pto generator which normally mounts behind a tractor. The pto generator is mounted on a sled kinda carriage that can be lifted by a tractor.
I have the intention of mounting just the generator (without the sled) under the series as a permanent fit (not as used behind the tractor with a removable shaft).
The nameplate on the generator says it shouldnt exeed 1500rpm but theres a reduction gear mounted on it that converts the 'standard' pto output of 540rpm from a tractor to 1500rpm for the generator.

Does anyone know what the rpm range is as taken directly from the centre mount pto ?
Would it better to remove the reduction gears and directly feed the pto output shaft into the generator assuming the pto output can go as high as 1500rpm ?

Regards,

Paul
 
I'm no expert in this but 25kva is a pretty big generator and 540rpm is not much faster than tickover so I would have thought the engine would stall at that speed trying to turn such a load. Running the engine at 1500 rpm will use a fair bit of fuel over long periods. I think the answer to your question is really to just try it and see. Am I miss reading 25kva? Should it be 2.5kva. I wouldn't think a 25kva genny would fit in or under a series.

Col
 
Hi, the rpm would depend on which gear the gearbox is in and I think the original fitment would have had a hand throttle and engine governor. The PTO is a direct drive from the gearbox output shaft before the transfer box you might find the ratio's from Ashcroft but you would need to know the suffix of your gearbox. Good luck with your project.
 
I'm no expert in this but 25kva is a pretty big generator and 540rpm is not much faster than tickover so I would have thought the engine would stall at that speed trying to turn such a load. Running the engine at 1500 rpm will use a fair bit of fuel over long periods. I think the answer to your question is really to just try it and see. Am I miss reading 25kva? Should it be 2.5kva. I wouldn't think a 25kva genny would fit in or under a series.

Col
The generator is 25 (twentyfive) kVA and dimensions are 30*30*60cm so I need to see where to mount it. But 30cm in height and flat against the floor should be possible I assume.
I only need to run it at intervals of 2 hours max for powering two 11kW chargers for recharging my electric racing/trackday cars when on the track (EV converted Mini Cooper S).
 
Hi, the rpm would depend on which gear the gearbox is in and I think the original fitment would have had a hand throttle and engine governor. The PTO is a direct drive from the gearbox output shaft before the transfer box you might find the ratio's from Ashcroft but you would need to know the suffix of your gearbox. Good luck with your project.

It's a 1966 109 diesel so hand throttle should be no problem. I have to look into the suffix of the gearbox not sure what it is at this time.
 
I've just done a quick calc and I recon that could need 50hp to drive it. That's allowing for the various losses. That's close to your peak output so you will need to match power curves. Will the generator have to run at a 50hz speed?
 
Put a 25kv generator on a 70hp tractor and you knows its working as the load comes on.
 
Makes sense. I did a quick search and 25kva gen sets have 2.5L to 3L modern engines so an old 2.25 looks more matched to 15kva. The engines designed for generators are rated at a lower RPM and a have bigger cooling systems. Its one thing to run a Series on a hand throttle for 10 mins on a PTO, but I think an hour could be pushing it. The mil spec series have a very large oil cooler to cope with static running.
 
I've just done a quick calc and I recon that could need 50hp to drive it. That's allowing for the various losses. That's close to your peak output so you will need to match power curves. Will the generator have to run at a 50hz speed?
Yes the generator is rated for 50Hz. The chargers are modified Tesla Model S (3-fase 11kW) chargers and they can run on anything between 100-240VAC, 50/60Hz.
So pushing the Landy to deliver 22kW for an hour or more could be a problem with the limited power or cooling it has ?
Would adding a bigger/better (water/oil) coolingsystem to the engine work or is it just the engine is not powerfull enough ?
 
Not as much room under the back as you think there is, dont forget the generator will need a mounting frame of some sort and associated bracketry.
Iirc there are two types of pto, std and heavy duty?

Just looked in the book, and it say max bhp the centre output pto can handle is 20 to 25bhp, or damage to the rear engine mounts may result, no mention if this is the std or heavy duty pto.

It also says an engine oil cooler rmust be fitted if the following are exceeded,
Power required
20bhp @ 1500rpm
24bhp @2000rpm
20bhp @2500rpm
10bhp @3000 rpm
Air temp above 20 degc
Running time above 30 minutes

So it would seem above and beyond a water pump/table saw the thing is not rated for heavy duty operation.
 
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The other problem with mounting a genny under the landy is that it will be prone to getting wet if the landy is used in bad weather.

Col
 
The getting wet thing is sure something to think about...
The generator is now mounted on a sled suited for mounting/lifting behind a tractor.
The proposed pto output shaft on the landy is somewhat at the same height as the pto input shaft on the generator.
So mounting the generator on removable/lockable wheels and just rolling it into place when needed might be a better option.
Now when I put the gearbox in 1st gear and rev the engine to 1500rpm, what would the rpm on the pto output ?
 
The more I look at the numbers the less I think the Series engine can cope, but that's not what would be on my mind. I think the "elephant in the room" is running a diesel generator for long periods at high power in a car park or pit area. I can see sentiment moving against this and I would expect that circuits will very soon mandate euro 5 or 6 engines for generators along with tough noise limits. I appreciate you are a racer not a climate activist (phew..) but Extinction Rebellion lost their high ground when a photographer got a picture of their hidden diesel generator. You don't want to be the person who undermines the green washed electric (aka renewable) racing meeting with fossil fuel. I think tracks will have to up rate their electrical supply pretty quickly and provide clean (at the point of use) electricity. It may be more fruitful to lobby for track chargers than faff about with generators. At worst the track could provide a EU5 silenced large generator at the far end of the site (behind a hedge..) and make it available to all as a stop gap. Our series is a camper and we are looking forward to getting out and about, so my past week has been faffing about with a 300W (ie tiny) generator and noise levels. Generators are pretty much banned from all sites now, ours could only be used away from any civilisation and its 72dB.
 
Well if I could at least charge with 11kW (one charger) it would help me a lot. I dont want to install CHAdeMo to the car and drive out of the pit area to charge at the closest public EVSE.
Anyway, one of the reasons not carrying an extra fuel-burner engine with me is exactly what you say about the diesel gens.
But using the allready needed diesel engine from the landy shouldnt be a big problem.
Apart from that most practicing days here are on weekdays when the main pit area is closed so no power available at all...
 
And on racedays they can put me near one of the takewaychipsfriermobiletrucks and i'll put some veggyoill in the landy. Nobody would now that i'm running the engine at the same time :)
 
I'm killing time before 4 hour zoom meeting on a UK energy technical committee, actually I'm retiring at this meeting, but what I'm seeing is that organisations really need to step up and those that are are getting the business. The idea that the track does not provide charging is not sustainable and neither is the one that there is no access to the chargers on practice days. I would expect rapid changes and personally I would not invest much time in my own provision but spend the time pushing the tracks to up theirs. In the long run its the only solution. Tracks are under a lot of pressure from near by residents (surely they knew there was a track when they moved there?) and this is about noise and emissions. Running a lot of generators could provoke a back lash just when the electric racing is making progress. Its a threat to the tracks and they are the ones that need to take action.
Don't' put veggie oil in the Landy !!!! It kills CAV pumps. I've done my own veg conversion and you MUST use an engine oil lubed pump or the quill shaft will shear on start.
 
Well if I could at least charge with 11kW (one charger) it would help me a lot. I dont want to install CHAdeMo to the car and drive out of the pit area to charge at the closest public EVSE.
Anyway, one of the reasons not carrying an extra fuel-burner engine with me is exactly what you say about the diesel gens.
But using the allready needed diesel engine from the landy shouldnt be a big problem.
Apart from that most practicing days here are on weekdays when the main pit area is closed so no power available at all...


Google Land Rover Broomwade compressor, and see the list of mods needed.

I wonder if you will get complaints about the diesel fumes/unburnt fuel whilst stationary running?
 
The more I look at the numbers the less I think the Series engine can cope, but that's not what would be on my mind. I think the "elephant in the room" is running a diesel generator for long periods at high power in a car park or pit area. I can see sentiment moving against this and I would expect that circuits will very soon mandate euro 5 or 6 engines for generators along with tough noise limits. I appreciate you are a racer not a climate activist (phew..) but Extinction Rebellion lost their high ground when a photographer got a picture of their hidden diesel generator. You don't want to be the person who undermines the green washed electric (aka renewable) racing meeting with fossil fuel. I think tracks will have to up rate their electrical supply pretty quickly and provide clean (at the point of use) electricity. It may be more fruitful to lobby for track chargers than faff about with generators. At worst the track could provide a EU5 silenced large generator at the far end of the site (behind a hedge..) and make it available to all as a stop gap. Our series is a camper and we are looking forward to getting out and about, so my past week has been faffing about with a 300W (ie tiny) generator and noise levels. Generators are pretty much banned from all sites now, ours could only be used away from any civilisation and its 72dB.


Rob cnan you even get Euro5 diesel gensets?
I have looked and all they go on about is noise.
 
I think so, reason I say that is that I run a Perkins in my series and I was looking at the new engines out of interest, obviously the Euro thing is a big deal and they make engines that comply but they also make generators. I'll look at bit more because its an interesting question. One of the big topics at my committee was hydrogen so perhaps that's how this will get resolved, I really don't know. I would expect tracks to be looking at putting in their own solar array and wind turbine (now that will upset the neighbours!) based upon this set up:
https://www.gridserve.com/braintree-overview/
 

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