OT maybe: Possible to power a generator with truck's diesel engine?

Have a 2013 Silverado 4x4 with the Duramax and Allison automatic.

I have read that GM offered the 3500 cab-chassis trucks with the option for a PTO.

Can I power a 3 phase output generator using the truck? Do I need a PTO on the transmission to do it or is there another way?

There is the below company that does aftermarket power generation add-on for trucks, using a PTO from the transmission . Anyone done something similar?
REAL POWER|Mobile PTO Shaft-Driven Electric Generators

Sure there is a way, but the answer you want is dependent on your requirement and you have not stated that. How many watts? What is the duty cycle? What is the maximum frequency variation allowed? Please define your needs.

I actually have a setup like that. Bought it at a auction not sure what it came off. Big thing is you would need to be able to set the cruise while in neutral. That way you can spin and hold the generator at the correct rpm.

We had several Miller 4 cylinder diesel powered welders. I thought they were capable of generating 3 phase power. Might be better served using one of these as they're already set up to do what you want. Relatively portable, their size and weight are the theft deterrent.

No personal experience.
Probably both yes and no.
Auto stuff is built to run 80-90% load for short times, and about 20-25% load the rest of the time.

Compare heavy vans, trucks, marine equipment in displacement boats, industrial generators, for HP vs mass and they are about 5x heavier for the same sustained output.
And typically/mostly run half the revs at the engine.
And they last forever, about 10-20-50.000 hours of use.

Marine displacement engines can often last 20-50k hours, Northern lights and similar, as can heavy machinery like earthmoving equipment.

Auto stuff might last 300k miles == / 60 == 5000 hours, as a minimax top end figure.
About 10x less longevity for 5x less mass (and 2-10x less cost, depending).

Certainly you can spin a generator, for some time, and if your HP rating is say 150 and you use maybe 30 hp, you are likely to do no damage short term. Imho.

It is one thing to use it as a genset at 30% load for say welding at a work site for hours or days.
Or powering a temp site for machinery, lights, ac, whatever.

Quite another if you are looking for 150 hp of power (on 150 hp rated output) on a continuous basis of hours or days.
I would suggest the auto engine will die (severely wear) in short order.
Like 2 days (8 hours) of 100% use would probably have worn out the auto engine, if gas.
And maybe 4 days of 100% use if diesel, depending very very much on the engine.

Mass is an excellent indicator of longevity in heavy sustained-load use.
A heavy diesel in a van of 150 hp, might have twice the mass of the gas engine in a 6 cyl car, or 2.5x more than a 4 cyl.
(Especially auto) Diesels should not run at very low loads == 10% for dozens of hours or more, without some peak load/revs in between.

Long story short, yes you can.
Do you expect the truck to be a truck after though or are you simply using it for a generator after the conversion?

Call up a company called Stamford. They make cheap and reliable gen ends.
Provide them the engine flywheel mount SAE number, rpm, voltage, kva... and they will provide a gen end that fits to it
Then comes the fun part of adding a controller/governor system. We always used deep sea brand controllers. Add a larger rad or much better fans to deal with the now stationary heat.
Lastly as stated above, don't expect wild hours of service from it. But it may do ok.

Coming from someone who manages a industrial gen/ electric motor repair shop, I would not bother. Find a not to ruined light tower or gen package at auction and buy it. Then it's all there done right. To code.
Just try to get one you've witnessed running and producing power.
Lot of bad equipment at auction.

steve-l said:

Sure there is a way, but the answer you want is dependent on your requirement and you have not stated that. How many watts? What is the duty cycle? What is the maximum frequency variation allowed? Please define your needs.

Click to expand...

To power the following equipment:

Industrial vapor steam cleaners: 480volt 48kilowatts and 380volt 18kilowatts

The steam cleaners would require the most power, out of all the equipment I would like to run. Frequency would have to be around 60hz. Continuous duty.

Having a standalone genset in the pickup bed takes up all the space and reduces rear-visibility. Don't want to be towing around a genset either.

Spud said:

To power the following equipment:

Industrial vapor steam cleaners: 480volt 48kilowatts and 380volt 18kilowatts

The steam cleaners would require the most power, out of all the equipment I would like to run. Frequency would have to be around 60hz. Continuous duty.

Having a standalone genset in the pickup bed takes up all the space and reduces rear-visibility. Don't want to be towing around a genset either.

Click to expand...

Well then, the answer is simple, no you cannot.

Stirling said:

Long story short, yes you can.
Do you expect the truck to be a truck after though or are you simply using it for a generator after the conversion?

Call up a company called Stamford. They make cheap and reliable gen ends.
Provide them the engine flywheel mount SAE number, rpm, voltage, kva... and they will provide a gen end that fits to it
Then comes the fun part of adding a controller/governor system. We always used deep sea brand controllers. Add a larger rad or much better fans to deal with the now stationary heat.
Lastly as stated above, don't expect wild hours of service from it. But it may do ok.

Coming from someone who manages a industrial gen/ electric motor repair shop, I would not bother. Find a not to ruined light tower or gen package at auction and buy it. Then it's all there done right. To code.
Just try to get one you've witnessed running and producing power.
Lot of bad equipment at auction.

Click to expand...

The truck is my sole mode of transportation, so definitely will need to remain a truck. Using the truck as the power source for the generator is attractive because of space consideration and less hassle than driving around towing a genset or light-tower power source.

All my equipment is stored in standard 2 car garages. There is no possibility right now for me to have the electrical circuits upgraded to 220volt of adequate amperage and install a phase converter to power the equipment. No space in the garage (inside or outside) to locate a genset or store a trailer mounted genset.

I want to sell off some of my equipment, but I need to power them up and run them before I can do so. I also would like to provide mobile vapor steam cleaning services ; my steam cleaners range from 3 phase 480 volt 48kilowatts to 3 phase 380volt 18 kilowatts . I am in a college autobody program ; my future plan was to provide soda blasting or vapor blasting services for the automotive restoration industry.

My plan was to just run the truck at idle when I need to power the equipment. I don't know the HP and torque rating for the LML duramax at idle, but full power is rated by G.M. as 397 HP and 765 ft / lbs . Idle is around 200 rpm.

steve-l said:

Well then, the answer is simple, no you cannot.

Click to expand...

What specifically is the problem? Not enough power at idle to power 48KW steam cleaner on continuous duty ?

Can I power a 18KW 380 volt steam cleaner? Or a 220volt 3 phase 21 amp pressure washer?

Should be doable. Look on ebay for the esd5500 gen controller. Needs a hall effect sensor, could probably mount it on the flywheel, and you need a solenoid to open the throttle.

I cant speculate as to what rpm you need to get 18 or 50kw from the engine. Maybe get a 1200rpm generator and direct drive it from the crankshaft through a 50$ honda civic cv axle(2 feet long, has a couple inches of axial travel), weld up a coupling between the generator frame and the front of your truck. Take the wheel hub from the same honda civic, cut it down and bolt it to the crankshaft.

The generator could have fold down legs like an ambulance stretcher. Roll it out the back of the bed, wheel it to the front of the truck and stick the cv axle in the hole.

regular 3ph 60Hz electric generators run at 1800rpm, rpm dictates 3ph frequency, so you cannot run diesel at idle or anywhere near that and expect 60Hz 3ph, if the engine torque curve allows for that, you can use a gearbox to speed up the output of the motor to the required generator speed to get those 60Hz, but that is another thing that can break, also induces some power loss, makes your electric power more expensive

next thing is the efficiency of piston engines, car engines are optimized for cruise speed, that is the rpm where they work efficiently, try to take the power from it outside that range - expect inefficient operation, diesel generator engines can have specific valve timing/lift and appropriate turbos (if it is a turbo engine ofc) for them to work efficiently in the rpm range required for the AC frequency the set has to produce

next is the truck being your sole means of transport, if you use the trucks engine to make AC and something goes wrong with the diesel, you are left with no means of getting anywhere on your own, that is a BIG problem IMO, I would never ever use my only means of transport in such a way, if your additional genset is acting up, you can drive somewhere to get it fixed or rent another one, if your sole car is down, things get expensive and complicated quickly

50kW continuous is a lot, regular car on highway makes something like 5-10kW, and you want to ask that poor diesel to work continuously 2-5x as hard as it is meant to, not a great idea, engine cooling might need some attention, I don't know, but I wouldn't expect those GM factory PTOs you mentioned to be expected to produce anything above 20kW continuously, unless there are significant design changes on that engine to handle that

Quick search shows about 100hp for 75kw. That's asking a lot from a truck at idle, I think the dmax high idle goes up to either 1500 or 1750. You would most likely need a separate throttle control. Which probably won't be cheap.

Go look at a 50KW generator end, then try to figure out how you would cram it under the truck and still have some ground clearance. I could be wrong, but I do not think you will find a PTO to fit a DMAX that would be suitable for driving a 50KW gen. Lastly, there is the problem of needing 480V and 380V, I'm not sure you can get both those voltages from a gen without at least reconfiguring the leads.

Only way I see this happening is if you mount the 50KW gen end in back of truck, cut out a slot in bed, disconnect drive shaft from rear axle and swing it upwards and connect to gen.

If your needs are 4.8KW you might get different answers.

What frequency variation is allowable, and how much power do you actually need?

Anecdotally, I have found undersized generators make wonderful soft starters for motors.

I would never say you can't do something, because that's like asking for people to prove you wrong, but ...

Generator diesels and vehicle diesels use different governors. The generator needs to run at a fixed rpm to produce a certain frequency. Usually that's 1200 or 1800 rpm for 60 hz.

In a vehicle, you'd like to be able to change speeds

The generator you are talking about would normally be about the size of a 4-71. That's not a small piece of equipment.

This idea seems like way more trouble than it is worth ...

Potatoes, galvanized nails, and copper wire. To create the a/c sine wave, just have two setups, and juggle them 180 degrees opposite. Done deal.



Seriously, wouldn't it be WAY easier and cheaper to snatch up an old DOT lighting/compressor/generator? I mean, if you could get past the 2 hour monologue, I'd tell you to contact thermite. He loves to talk about the 90 million gensets he has modified to run the free world.

Of course you can run a generator from a trucks diesel engine. How creative do you want to get, seeing it's your daily?

3 ton box truck, generator in the back and remaining space used to house the steam cleaners. Decals to match. But this assume a real business with actual needs.

Just because you have a Duramax /Allison 3500, Doesn't mean you have a gear in your transmission for a PTO. My 2013 Dura/Allison WORK TRUCK shows a optional PTO on my bill of sale, Pull the cover plate on the trans, and make sure there's a corresponding gear in there; The PTO drive assembly that bolts to the trans. case is quite expensive also. Dave [acme thread]
A dealer could probably tell by your Vin.# If it has the option.

You can not take high hp/continuous output from a standard PTO......it will fail in a few hours running...........high HP pto s for trucks normally use a unit inserted between the truck crank and flywheel in a separate housing with a geared takeoff.You often see these units in mobile equiptment,such as cranes...........the power output you are wanting is around 75kva......impossible thru any gearbox PTO.