Thermo King / Isuzu motors for generators

[pmsmechanic]

At 1800 rpm a 15Kw alternator would be a fit .

That's kind of where I was thinking too.

I'm at the point where I'm rethinking my end of the project. I'll still build the generator for the neighbor but I'm thinking that this is more than what I need for me.

Right now I have a 2200 watt inverter generator that is adequate for the house if the power goes off. I use this for night. The only thing it won't run is the pressure system. We can flush the toilets with a pail if we need to but it would be nice to have a shower. A sponge bath is adequate though.

I have a 2 cylinder air cooled Lister (7 hp) that I bought at an auction years ago. I have a 7500 watt generator that I plan to attach to the Lister. I realize that it's a lot more generator than the Lister will run but the original plan was to set it up to be able to run it either with a pto for when I needed more power and just use the Lister the rest of the time. I'm not sure it'll run the welder so I haven't ever finished the project. Now with Covid-19 there is time.

If the Lister will start my pressure system.... other than welding and a 5 hp air compressor I really don't need a larger engine running most of the time. I think for welding and running the air compressor a pto generator is all I really need. A 20 kva should be more than adequate for that. I think I'm going to finish off the Lister project w/o pto and see where I end up. Then we'll make some educated decisions.

 

[buickanddeere]

I would rather have more alternator that engine . To avoid high winding temperatures .
Conversely, an consumer grade alternator should operated continuous at 80% of rated current. Note I said current as too often prospective generator purchasers have $$$ signs in their head, add up watts and want the absolute cheapest genset. They do not understand that a 1500watt electric motor loads the system with somewhere between 1800-2000 Volt amps.

 

[Industrial Toys]

You can never compare someone that just wants a tool, as cheap as possible, to an Enthusiast. I mean my truck is as stock as the day it drove off the lot. Some guys couldn't handle that.

High winds yesterday. Power flickered for a moment, but held. Dratts! Maybe next time. Had one 7.5 set all warmed up.

 

[pmsmechanic]

I was brousing through the Central Georgia website the other day. There is good information there.

I found a hp/torque chart for the little 3 cylinder Isuzu. (model 3LD1) It looks like I have 21 hp at 1800 rpm on that one. Good for a little over 15,000 watts.

I looked for a chart for the Thermo King/Isuzu C201 engine. So far nothing. Even though the service manual mentions generator use there is very little information about those old rnotors being used as generators online. Maybe one of you will have better luck.



Line B is continuous torque and line D is continuous hp. And I just noticed that 1800 rpm puts it at the lowest fuel usage too.

 

[BrokenTrack]

The real question is not if people want a bigger generator or not...of course they do, they can live a little more comfortably if they do. So it is about spending the money, or putting time into a project, to get that bigger generator.

A better question to ask is, how much are you going to regret the purchase/build of a bigger generator down the road?

I have found, on the profound things, once the money is spent, you never think about it again, and are very glad you got what you got.

I know that with my building my own genset: I will never regret having more back up power, 60 days of fuel supply, an additional heat source for my home, and putting a lot less hours on my tractor. I will never regret doing the project, so why would I question it up front, or in the middle of the project? Like many things in life, you have to do the work up front, to reap the rewards later. I know that, so I start projects and finish them.

But the real question is: how often is a particular home out of power?

I lose my power quite often because of the rural location, and for extended outages. The last three outages in the last 6 months were for 24 hours, 72 hours, and 18 hours. So for me, I know the final project is worth the hours I am spending on it now. For a person that loses power an hour and then it is back on...yeah, it is a different story...

 

[BrokenTrack]

I have had micro-generators, small generators, and now a bigger one, and what I have found is, there is no comparison for convenience. It is what you do not have to do on a power outage that makes it all worth it.

With a bigger one, hard-wired into my home, I can walk anywhere, flip on a switch, and have light. That seems simple, but it is really nice: no running extension cords, plugging in lamps, heating water on the stove, trying to find a flashlight...trying to find good batteries for that flashlight....

Sure it took some work on my part to get to this point in life, but I have read the stories of people with small generators who are getting by, not realizing that their little machines are damaging some major appliances because they are trying to run too much, with too little volts/amps/hertz. I propose that pulling a burned up well pump out of a well casing 150 feet down is almost as much money and effort as buying or building a pto generator that has some size to it. And replacing a burned out refrigerator from a brown-out small generator would have the same cost as a pto generator.

I think a lot more appliances die prematurely from the use of small generators than what people realize, just because they seldom die while operating them with a generator. Instead they die down the road with the homeowner not realizing it was done because six months before it was running at 50 hertz for 8 hours during a power outage instead of 60 hertz.

We all have tractors which is why we are on here, so why not spend $1500 of a new one/$800 for a used pto generator of size, and have all the convenience thereof, instead of spending $400 for a smaller one, and then replacing appliances? To me that just does not make sense.

 

[BrokenTrack]

Of course convenience has a cost...

My parents have a 14 KW Generac Generator that is really nice, BUT it also cost them $6000 when they got done installing it. Good for them, they have the money, and wanted standby back up power.

So do I, and while I have plenty of money, I cannot justify spending $6000 to get it. But in life there is another way: if you do the work that you normally would write a check for, you get to keep your money. In other words, do the work yourself.

I am doing just that.

A purchased generator has an engine, fuel tank, and generator...all things I have, so I am putting them together. In doing so, I will spend 10% of what my parents paid, and get about the same thing. (Mine has to be manually controlled, but my wife can turn a key to get power if we lose grid-power.) The real price I am paying, is using my own time to build it.

To save $5400... It really is a good use of my time right now. Once it is up and running, I will never regret taking the time to build it.

Note: I LOVE my PTO Generator, and would not trade it for anything, so I highly, highly recommend them, because cost wise, they make so much sense. I am just switching to a dedicated engine because like PMSMechanic, I have a few diesel engines kicking around and can use them. There are reasons for that...good reasons...but a PTO generator is a very smart purchase for someone with a tractor for sure.)

 

[RalphVa]

I'm not an expert in sizing motors to generators, just a old retired chemical engineer who sized lots of compressors and pumps. Love the 12.5 kw Isuzu driver I have obtained from Central Maine Diesel in late 2012.

Doubt it needs much oversizing because it very seldom will get to full power because the operating kw load is generally waaaay below maximum. For instance, my average house usage is about 2.5 kw. So the 12.5 kw Isuzu sits there mostly unloaded a lot. Plenty of room for spike startups.

So, I'd think just applying a generator (like a motor) efficiency factor of about 98% to calculation of what kw a hp motor will put out would suffice.

Have no idea what hp the Isuzu I have is. Might be in the owners manual somewhere. If you want, I can look.

Ralph

 

[BrokenTrack]

Have no idea what hp the Isuzu I have is. Might be in the owners manual somewhere. If you want, I can look.

Is this the unit you have Ralph?

If it is, it says it is 22.5 horsepower.

Looks like a very nice unit.

Isuzu 12 kW Diesel Generator

 

[RalphVa]

Looks identical to mine, a 3CE1, except for the exhaust (mine goes out over the right side of the radiator) and the control panel (mine is perpendicular, over the generator and accessible at the end opposite the radiator). Mine also sits atop a 60 gallon tank. Think the tank is all part of the enclosure build. 22.5 hp sounds about right. I pulled the book. At 1800 rpm, it's 22.1 hp. It's 1.64 L.

This is the sweetest diesel apart from the VW TDI we had for nearly 7 years (VW bought it back). If you didn't hear the timer on the glow plugs but hear it start, you'd never know it was a diesel unless you stood close to where the exhaust is blowing and smelled it. No smoke ever. No clatter.

I found a fuel usage curve vs. kw somewhere. Could not find it in my file. Less than 0.3 gph at the average household usage rate of around 2.5 kw. It has run close to that. Thought it was right on the curve at 0.23 gph but think I overfilled it (up to the filler cap) once and think that put the total usage up a bit to near 0.3 now. Only have about 150 hours on it since early 2013. Changed the oil once at 50. No other maintenance other than keeping it clean.

Control panel on both the generator and circuit breaker box consume apparently a lot of amperage. My old outdoor Battery Tender finally bit the dust about a week ago. Got a new 1.5 amp one that charged it up from 2 days off tender to "green" now. Had to also go to about the largest marine battery that the local Central Battery has. A smaller one didn't cut it.

Ralph