Fairbanks Morse Z lightplant

Hello,

I have a Fairbanks Morse Z 32volt light plant and I was just curious to see if anyone can tell me it you can "turn down" the voltage cutout on this so I could run the engine a little slower than top speed of 500 rpm and still make a light or two work.

Thanks,

Tim

Tim;

Connect a volt meter to the out put and regulate the speed of your engine untill you get it down to around 12 volts and that voltage equipment is fairly easy to come by. I have a 12 volt Tiny Tim generator that I use a radiator fan from a modern car to keep me cool. I mounted it in a wooden box with 1/2" hardware cloth to keep some one from getting their hands in it. The motor has a permanent magnet field and by turning the plug over you can run it in either direction. 12 volt light bulbs are easy to come by as well.

"DELCO DON"

Thanks for the reply Don, but I think that I worded my question a little wrong. I have a 32V light bulb hooked to my light plant and the generater doesnt seem to even start to make any current to about 450-500rpm. It's like someone just turns on a switch at that speed. At low speed there is no current flow. I was just wondering if there was somewhere that I can ajust the cut-out on the unit.

Thanks again,

Tim B

Tim;

I'm sorry but I don't know that much about the Fairbanks generators I would think you could do some thing to make it start charging at a slower speed. If it were a Delco you couldn't slow it down to make it charge less. They were made to opperate at the maximum output. There was a guy in our engine club that took a Model-600 and put a float carburetor on it with a throttle on and slowed it down to run a 12 volt bulb. I don't know what he did with the reverse current relay to keep it latched up. He may have fastened it up. I have never given it much thought. I like to make mine run as they were intended to.

Maybe Gus or some one will help you with the details of the Fairbanks.

Don't give up some one will come to your aid.

"DELCO DON"

Almost all these old generators have to get up to a certain speed before they self generate enough field current to make them start producing any real power. Question, if the unit is once up and producing electricity, what happens if you slow the engine back down. Does the output voltage suddenly drop off, or does it just become less.

If the output just starts slowly dropping off, you may be able to make the unit start producing power at a lower speed by exciting the field with a battery for a moment after starting the engine. You just have to make sure that you momentairly connect with the same polarity as it normally is when the unit is up and producing power.

There is usually some residual magnetism in the pole pieces of the field coil assembly that allows the generator to start producing power as soon as it starts rotating. In your case, there may not be sufficient residual magnetism in the pole pieces to make the unit start producing power until it gets rolling over at a fast speed.

The output of the generator is used to supply the field current and it becomes sort of like, which comes first, the chicken or the egg. You have to have field excitation to produce power and you need power to produce the field excitation. That little amount of residual magnetism in the field pole pieces is what allows the generator to sort of lift itself by it's own bootstraps initially.

That may not be your problem, but you might want to consider the possibility.

Thanks for the info everyone. The generator does drop in voltage just a little bit at just a fifty or so rpm's slower.

What is happening is that when I have the engine running off of the terminal wire for the buzz coil and it miss's a beat or two, the engine will shut off because of no current being generated.

Thanks again everyone.

Tim B

Tim, The regualtor is not adjustable. If you want to run at a lower speed you can re-pulley the generator. I have a 1 1/2 and a 3, the three seems to want to shake my trailer a it's rated speed. I replaced the pulley with one abot 3/4" smaller than the original and it helps a lot. The slower engine speed shouldn't be a problem as long as you don't run a large load. Happy generating.

Thanks again Gus,and everyone else.

I guess that I will just keep running it at the rated speed. It's just old and I didnt want to rush the ol' gal all day long at the shows.

Tim B

If you have a battery set, you can run the outfit as it was intended to, that is, run your lights from the battery and start the plant occasionally to charge them. That will give you some quite time in between to discuss your plant with fellow enthusiasts.