Test Run

Today's test run was meant to deal with the following characteristic I observed with the last run. With no load on the generator, engine speed is set to output 120 volts from the generator (no load). Then when a load of 1800 watts from a hairdryer is put on as a load, the line voltage drops to about 105 volts. I wanted to see if I could then set the govenor to push rpms up so that I'd get 120 volts out. No, it didn't work. Any attempts to increase engine speed with the generator under load were met with vibration and bucking. So I think that's about it, maybe an output of 1500 watts from this setup.

A Good Generator Setup

Here is the final setup. It works pretty well. I can make 120 volts with no problem and the unit is shown here running an 1800 watt hair dryer and a 100 watt light bulb. This is the maximum juice I can get out of this arrangment. Make sense since I'm probably only getting about 5 horsepower from the engine at this rpm.

A New Engine Generator Arrangement

I'm convinced from reading about power transmission that my belt length is too high. A formula I found is that the pulley centerlines shouldn't be more than sum of the diameters of the twopulleys. That would mean about a distance of about 12 inches in my case. I mounted the generator on the other side of the engine so I could get it closer. A picture of this arrangement is shown here.

Puzzle Continues

I rechecked the belt alignment and tried the engine - generator setup again. Once again, can't make more than 100 volts before the engine setup bucks like mad. This would be an engine rpm around 1500. Someone is not a happy camper. Back to the books.

Engine at 1800 rpm

I've installed the new 8 inch pulley on the flywheel of the engine. Setup the generator with a 4 inch pulley which I had from my Listeroid project. Fired up the engine and found that I couldn't make more than 100 volts before the engine started to vibrate and buck like mad. Now I'm really confused.

Chinese Diesel Generator - Try #2

I decided that I need to run this engine around 1800 rpm. With a generator speed that must be at 3600 rpm to make 120 volts, and the smallest pulley available with a 1 inch shaft being about 3.1 inch I made the decision to have a new engine pulley machined if cost is not excessive.

Meadow Valley Machine is going to make a new engine pulley 8 inches in diameter so with a generator pulley of 4 inches, I'm where I need to be.

A Puzzle

I made some rpm measurements by using a noncontact tachometer. The engine runs smoothly at speeds between 1500 - 2800 rpm without a load. When belted to the generator any engine speed above about 1600 rpm results in a lot of vibration. I checked belt alignment and tension several times. They seem to be nearly perfect but I don't have a stable setup. Have to go back to the books.

Chinese Diesel Generator - Try #1

Here, the engine is running a 5 kW generator by spinning it at 3600 rpm. With a 4 inch pulley on the engine and a 3.1 inch pulley on the generator, the engine speed is about 2800 rpm, its maximum rated speed. The engine is not too happy at this speed although it makes acceptable line voltage. I wouldn't want to run this setup without standing over it ready to shut it down at any time. Note the distance of the belts from center-to-center.