Is my generator big enough?

[jungleexplorer]

I have have a Coleman 2500 watt generator and I am wondering if it will pull my rooftop AC on my 19ft travel trailer? My rooftop AC is a Duo-Therm Model: 57915-541. It does not say how many watts it pulls on the plate that I can find. What do y'all think?

[ol_Bombero-JC]

jungleexplorer wrote:
I have have a Coleman 2500 watt generator and I am wondering if it will pull my rooftop AC on my 19ft travel trailer? My rooftop AC is a Duo-Therm Model: 57915-541. It does not say how many watts it pulls on the plate that I can find. What do y'all think?

Just an "FYI" -
You will find *LOTS* more generator info on the *Tech Issues* forum here.

Try some searches (any generator topic) limited to that forum.

~

[Fredzo]

westend wrote:

jungleexplorer wrote:
Every small engine mechanic I have talked to confirms that ethanol is destructive to most small engine for one reason or another

You'd have to define "destructive" for me to believe that.

Think about this for a moment. If the amount of water in a fuel tank is that great that water would be separated and introduced into the engine, the engine wouldn't run. If it's a partial mix of water and fuel, steam is created and should exit the exhaust with each combustion stroke. If water retention is that great an issue, every Briggs and Stratton engine with a vented fuel cap that was left outside for storage would have failed due to the water that enters the cap and resides in the tank. There are millions of small engines operated daily that are using ethanol blended gas, along with cars and trucks, that suffer no ill effects.

FWIW, at one time, I serviced a fleet of different small engines (125 or so). During winter storage every fuel system was topped off with ethanol blended fuel and a stabilizer was added. 4- 5 months later, the equipment was brought back into service and every engine started with no ill effects except for 10 engines, all 6 hp. Kawasaki's. All of those engines had a clogged primary jet. I maintained this fleet for 5 years and the procedures remained the same except for the Kawasaki's, which we drained and fogged. Sometimes, it's about the design of the fuel system and not about the fuel.

This is the exact procedure that I use on my boat. The MoHo is used year-round, so I just make sure it's started , both engine and genny, monthly, and that a load is put on the genny.

[jungleexplorer]

westend wrote:

jungleexplorer wrote:
Every small engine mechanic I have talked to confirms that ethanol is destructive to most small engine for one reason or another

You'd have to define "destructive" for me to believe that.

Think about this for a moment. If the amount of water in a fuel tank is that great that water would be separated and introduced into the engine, the engine wouldn't run. If it's a partial mix of water and fuel, steam is created and should exit the exhaust with each combustion stroke. If water retention is that great an issue, every Briggs and Stratton engine with a vented fuel cap that was left outside for storage would have failed due to the water that enters the cap and resides in the tank. There are millions of small engines operated daily that are using ethanol blended gas, along with cars and trucks, that suffer no ill effects.

FWIW, at one time, I serviced a fleet of different small engines (125 or so). During winter storage every fuel system was topped off with ethanol blended fuel and a stabilizer was added. 4- 5 months later, the equipment was brought back into service and every engine started with no ill effects except for 10 engines, all 6 hp. Kawasaki's. All of those engines had a clogged primary jet. I maintained this fleet for 5 years and the procedures remained the same except for the Kawasaki's, which we drained and fogged. Sometimes, it's about the design of the fuel system and not about the fuel.

Hey, I am just stating what the professionals that repair small engines have told me, you can believe it or not. I know from my own personal experience that ethanol blended gas has caused me way more problems with my own small engines. I used to run a lawn care service with my brother when I was a young man. I never did anything to my lawn equipment when I stored it for the winter. Ever spring, after sitting all winter with the gas in it, all my equipment would start and run just fine and I never had a fuel issue with them. After they started putting ethanol in gasoline, I have had to buy countless (or have them repaired) weed eaters, lawn mowers, rototillers etc, because I forgot to drain the ethanol gas out of them before storing them for the winter. Now, those are the facts. I just don't understand what some peoples love affair with ethanol blended gas is. It is not necessary and there is no great benefit to using it, and there are many detrimental downsides aside from what it does to small engines. But hey, if you like it and think it is superior in function and presents less problems then non-ethanol gasoline, knock yourself out; I myself will use propane.

[westend]

jungleexplorer wrote:
Every small engine mechanic I have talked to confirms that ethanol is destructive to most small engine for one reason or another

You'd have to define "destructive" for me to believe that.

Think about this for a moment. If the amount of water in a fuel tank is that great that water would be separated and introduced into the engine, the engine wouldn't run. If it's a partial mix of water and fuel, steam is created and should exit the exhaust with each combustion stroke. If water retention is that great an issue, every Briggs and Stratton engine with a vented fuel cap that was left outside for storage would have failed due to the water that enters the cap and resides in the tank. There are millions of small engines operated daily that are using ethanol blended gas, along with cars and trucks, that suffer no ill effects.

FWIW, at one time, I serviced a fleet of different small engines (125 or so). During winter storage every fuel system was topped off with ethanol blended fuel and a stabilizer was added. 4- 5 months later, the equipment was brought back into service and every engine started with no ill effects except for 10 engines, all 6 hp. Kawasaki's. All of those engines had a clogged primary jet. I maintained this fleet for 5 years and the procedures remained the same except for the Kawasaki's, which we drained and fogged. Sometimes, it's about the design of the fuel system and not about the fuel.

[azrving]

jungleexplorer wrote:

westend wrote:
You can overcome your ethanol issues by using a fuel additive/stabilizer. Yes, stored gasoline can be problematic but glazed cylinders or glazed rings are not a part of that. Gasoline with ethanol added doesn't destroy power equipment engines, it usually clogs the main jet so that they don't start. Higher horse power outboard engines are a different story. The modified ignition temperatures have been tested and documented to cause engine problems. I have a certification plaque for power equipment that says I'm qualified to work on small engines, not necessarily to comment on them, though, lol.

Or better, we can buy non-ethanol gasoline (if you can find it) or we could just stop turning food into fuel, use it to feed the starving millions.

Every small engine mechanic I have talked to confirms that ethanol is destructive to most small engine for one reason or another. I had brand new trash pump that I had only used once and let it sit for one month. When I tried to start it, it ran for a few minutes a quite and would not start again. It was under warranty (or so I thought) so I took it in for repair. The mechanic said that the ethanol gas had separated in the tank and had caused glazing on the cylinders. He had to replace the carburetor and the rings. The cost was $175, but the warranty (I found out) specially stated that the it did not cover engine damages as a result of using "ETHANOL LADEN GASOLINE". The mechanic told me that even fuel stabilizers ethanol gasoline will separate in as little as 2 months and that the only way to prevent damage to the motor was to run it completely dry every time I used it with ethanol gas. I followed his advice ran it dry each time I used it and the motor ran find for three years and I moved over a 20 million gallons of water with it, and then gave it to a friend who drills water wells and he is still using it today. My point here is this; yes, you hold your tongue just right and take all kinds of special precautions and you can prevent ethanol gas from destroying your engine, but the majority of people do not (nor should they have to) and it is causing huge amount of unneeded waste. That, and it is just plain stupidity to turn food into fuel in a world where there are millions of people that are starving for lack of food. But that is another subject.

Yes, the bottom line is to drain it. One of my last jobs was at a JD dealer. When we had a storm 40 gen would come in. 98 % were bad fuel. It's not a generator issue, it is as you are saying a fuel issue.

People would be totally ticked off because many of them would buy the gen and take it home, never read the directions, never pay attention to the paper we gave them and gas it up and try it out then wheel it into the garage and forget about it.

Sometimes when helping them load it up after repair I would say "would you like to not come back here"? often times it got their attention and I would say then listen closely to what I telling you.
1. Don't store fuel in the tank. EMPTY
2. At minimum run it out of fuel and put the choke on and wiggle the genny as it dies out so as to suck as much fuel out of the bowl as possible.
3. Better yet run it until it stops. Open this little screw on the carb bowl (if equipped) or loosen this center nut for the bowl and let the fuel drain out.
4. There could still be a problem of hard needle rubber or stuck float in 2 years but this is the most you can do.
5. Do all of the above and now put seafoam in the tank and flush the carb by doing the drain thing.

I do the seafoam thing and store my gas in a red plastic 6 gallon jug. I then rotate the fuel by dumping it in the car and have gone 6 months

We hung a notice paper on every piece of equipment repaired that said. DO NOT USE FUEL THAT IS OVER 45 DAYS OLD
Having fuel in a sealed fuel can isn't so bad. The problem comes in when the fuel sits in the carb bowl. The bowl is vented to the atmosphere. As the fuel evaporates it gums and chemically eats the aluminum. Fuel system destruction is not new, it's just worse.

I was repairing small engines 45 years ago that you would swear someone urinated and vomited in the gas tank and carb. The fuel was stale.
This isn't new it's just different and of course, worse now.

[jungleexplorer]

westend wrote:
You can overcome your ethanol issues by using a fuel additive/stabilizer. Yes, stored gasoline can be problematic but glazed cylinders or glazed rings are not a part of that. Gasoline with ethanol added doesn't destroy power equipment engines, it usually clogs the main jet so that they don't start. Higher horse power outboard engines are a different story. The modified ignition temperatures have been tested and documented to cause engine problems. I have a certification plaque for power equipment that says I'm qualified to work on small engines, not necessarily to comment on them, though, lol.

Or better, we can buy non-ethanol gasoline (if you can find it) or we could just stop turning food into fuel, use it to feed the starving millions.

Every small engine mechanic I have talked to confirms that ethanol is destructive to most small engine for one reason or another. I had brand new trash pump that I had only used once and let it sit for one month. When I tried to start it, it ran for a few minutes a quite and would not start again. It was under warranty (or so I thought) so I took it in for repair. The mechanic said that the ethanol gas had separated in the tank and had caused glazing on the cylinders. He had to replace the carburetor and the rings. The cost was $175, but the warranty (I found out) specially stated that the it did not cover engine damages as a result of using "ETHANOL LADEN GASOLINE". The mechanic told me that even fuel stabilizers ethanol gasoline will separate in as little as 2 months and that the only way to prevent damage to the motor was to run it completely dry every time I used it with ethanol gas. I followed his advice ran it dry each time I used it and the motor ran find for three years and I moved over a 20 million gallons of water with it, and then gave it to a friend who drills water wells and he is still using it today. My point here is this; yes, you hold your tongue just right and take all kinds of special precautions and you can prevent ethanol gas from destroying your engine, but the majority of people do not (nor should they have to) and it is causing huge amount of unneeded waste. That, and it is just plain stupidity to turn food into fuel in a world where there are millions of people that are starving for lack of food. But that is another subject.

[azrving]

Only one thing matters when it comes to the generator winding side and that is hertz. 60 hertz is 3600 rpm. Yes the gen may do it on propane but it's going to be through the governor and a wide throttle opening. So if on propane go about 20 % larger. Well...they dont give you the option to increase horse power in a particular wattage range. They sell you a little larger unit because it's on propane.

So X unit on gas will often be upsized slightly for propane. Same issues with elevation and power.

So as pinao originally said, you would basically consider it to be about 20% smaller because it's on propane. That's just how I would describe it.

When working on a portable generator, to increase or decrease the hertz, you adjust the governor speed. 3600/60 hertz. It's the ac sine wave/winding design. Rotor and windings are flashing past each segment at 60 times per second.

Some units that are 1800 rpm are wound differently but have to be still putting out 60 hertz. I have never worked on those but it seems like a great idea to slow the engine as a lot of a generators noise is from the mechanical side not the exhaust side. Any engine will be quieter at 1800 rather than 3600.

You cant put a Honda muffler on a champion and have a Honda.
I have worked on generators that people have tried to over muffle and it increased the back pressure too much and melted the control panels and wiring. The muffler/exhaust is not just noise, it's heat.

You can do it but the exhaust system has to be large and be able to remove enough heat. It defeats the intent of a portable generator. A lot of the Hondas or Yammies price isn't in the muffler, it's in the engineering and tolerances of the engine.

[azrving]

jungleexplorer wrote:

pianotuna wrote:
Hi,

Here is why you loose wattage from a generator:

I am not sure if I understand how this data relates to the output of the generator. Generators (portable power plants, to be technically correct) consist of two separate parts, the actual generator that produces electricity and the motor that turns the generator. The output of a generator is related to the output capacity of the actual generator, not the torque capacity of the motor. As the amperage draw on a generator increases, so does the torque required from the motor. Portable power plants have a governor that automatically increases the amount of fuel to the motor as the torque requirements increase. So the reduced energy of propane vs gasoline have no direct correlation to the output capacity of the generator. It just seems to me (and I am probably wrong), that with propane, the motor would just consume more fuel to achieve the torque necessary to achieve the maximum potential of the generator.

I understand where you are coming from. I guess the other way to look at it would be not so much in watts when it comes to propane but in engine size. Yes it would use more fuel but it would be at a higher throttle opening. So in overall sizing of the unit the engine is now running at 20 % more throttle opening. So it all depends on how a person is approaching it. If it's from an engineering prospective it gets sized according to a certain expected life span vs load and engine wear.
That's why people go back and forth about all this stuff. Someone will say can my engine/gen do this or that. People will respond and possibly say no, dont do that, then they come back and say I did it and it's working so you are all wrong.
The part that isn't taken into account is engine wear, fuel use or heat production as the unit is at the edge of its capacity. It's sort of like towing capacity, yes it will pull it, but do you want to or should you. When being over capacity with a tow rig lives could be lost, when over doing it with a generator and ac unit all you will be out is $600 or $700 for ac and a generator.




I

[jungleexplorer]

pianotuna wrote:


The engine only has so much HP and is rated on gasoline. If you convert it to propane it has less HP. When you have less HP it does not have enough to pull the amount of watts that the generator pulls.

IOW's the engine will not have enough power.

If the maximum torque capacity of the motor is precisely balanced with the maximum torque needed by the generator when operated with gasoline, I guess what you are saying would make sense. But if the motor is a little oversized (which is how I would design any power plant; to account for all unknown variables, if you know what I mean?), then there would not be any or very little reduction of wattage potential. It all depends on what the torque potential of the motor is, which would take detailed knowledge of the power plant design, which I don't know. The only way for me to really tell would be in actually testing though.

If my calculations as far as wattage are correct (13.8 amps @ 115 Volts = 1587 watts), then 2000 watts should be plenty to run my AC with a little to spare. But you and I both know that practical application beats theoretical calculations every day of the week. Especial now days, when power plants never live up to their listed potential, as a result of poor manufacturing quality and controls.

[westend]

You can overcome your ethanol issues by using a fuel additive/stabilizer. Yes, stored gasoline can be problematic but glazed cylinders or glazed rings are not a part of that. Gasoline with ethanol added doesn't destroy power equipment engines, it usually clogs the main jet so that they don't start. Higher horse power outboard engines are a different story. The modified ignition temperatures have been tested and documented to cause engine problems. I have a certification plaque for power equipment that says I'm qualified to work on small engines, not necessarily to comment on them, though, lol.

[azrving]

jungleexplorer wrote:

rjxj wrote:
Well.....the manual valve may be ok for testing and very temporary but I would go with a regulator.

Are you talking about the mower or the generator?

Every propane system should have a valve/regulator

[jungleexplorer]

rjxj wrote:
Well.....the manual valve may be ok for testing and very temporary but I would go with a regulator.

Are you talking about the mower or the generator?

[azrving]

Well.....the manual valve may be ok for testing and very temporary but I would go with a regulator.

[Turtle_n_Peeps]

jungleexplorer wrote:

pianotuna wrote:
Hi,

Here is why you loose wattage from a generator:

I am not sure if I understand how this data relates to the output of the generator. Generators (portable power plants, to be technically correct) consist of two separate parts, the actual generator that produces electricity and the motor that turns the generator. The output of a generator is related to the output capacity of the actual generator, not the torque capacity of the motor. As the amperage draw on a generator increases, so does the torque required from the motor. Portable power plants have a governor that automatically increases the amount of fuel to the motor as the torque requirements increase. So the reduced energy of propane vs gasoline have no direct correlation to the output capacity of the generator. It just seems to me (and I am probably wrong), that with propane, the motor would just consume more fuel to achieve the torque necessary to achieve the maximum potential of the generator.

The engine only has so much HP and is rated on gasoline. If you convert it to propane it has less HP. When you have less HP it does not have enough to pull the amount of watts that the generator pulls.

IOW's the engine will not have enough power.