Generator Electrical Engineering Question

[dodge man]

I had a spun bearing in the front wheel hub of a car once, and peening the hub left it pretty loose. I went to a machine shop and they used "shim stock" to fill in around the loose bearing. It was a roll of paper thin material, I think brass, and tightned the bearing up really well. It think it comes in different thickness. It was not the greatest fix in the world, but it was a restored show car and didn't get driven a lot. For a generator that doesn't get used a lot, it may fix your bearing problem.

 

[E/S]

I am confused, on a 120 / 240 v system shouldn稚 each phase be 120 degrees out, not 180 degrees?

E/S

 

[dangier_VA]

Meant to say .020" slop-my error. The end bell has a steel sleeve in it now. Sounds like the best idea at this point.

 

[BobRip]

I am confused, on a 120 / 240 v system shouldn稚 each phase be 120 degrees out, not 180 degrees?

E/S

Should be 180 degrees. For a 3 phase system it is 120 degrees.

127 to 129 is not a real high voltage. By the time you run some wire between it and the load you will loose some voltage. I have not heard, does this unit has a voltage regulator? Is it adjustable?

My generator runs at 62 hertz when unloaded and drops down as you load. Of course if you run yours at higher hertz (and it has no regulator) it will put out even more voltage.

 

[E/S]

If it is 180 degrees, tell me how that is possible?
On normal electrical service 120 v. is 1 leg of the 3 phase line, 240 v. is 2 legs of the 3 phases and then you have 240 v. 3 phases with all 3 legs.
I see no conceivable way you could change the phasing, short of some kind of equipment not normally used in electrical services.


E/S

 

[LD1]

If it is 180 degrees, tell me how that is possible?
On normal electrical service 120 v. is 1 leg of the 3 phase line, 240 v. is 2 legs of the 3 phases and then you have 240 v. 3 phases with all 3 legs.


E/S

Because that is incorrect.

I dont understand exactally how it all works either, but 3-phase power lines running down the road have the 3 main wires (each phase) and then the ground. If you have 3 phase service, it requires 3 transformers.

Out here in the rural sticks, we only have single phase power. 1 Hot wire, and then the ground (neutral). I only have those two wires comming to my house, and I only have 1 transformer, but still have 240v and not the 120 as you suggest anly 1 phase would be.

 

[mbohuntr]

Sychronizing the phases is important in that if you are indeed adding the phases together to get 240, each phase must be 120 volts, and at the correct timing and polarity. a phase is determined by the timing of the magnetic field. If you think of two identical roller coasters moving in tandem, their combined height at the top in that instant of time is the total of their respective heights. If one has already gone past top in that moment in time, the combined height(voltage) is less. If they are 180 degrees apart, and have the same polarity, they will cancel each other out. I would think they are 180 degrees apart, and opposite polarity. I'm no generator tech, but I do have quite a bit of theory in my education. I would think generator sine waves are dirty, and most modern circuits should invert them, and then generate their own clean sine wave, like a windmill would. A tech will have the solution.

 

[BobRip]

If it is 180 degrees, tell me how that is possible?
On normal electrical service 120 v. is 1 leg of the 3 phase line, 240 v. is 2 legs of the 3 phases and then you have 240 v. 3 phases with all 3 legs.
I see no conceivable way you could change the phasing, short of some kind of equipment not normally used in electrical services.


E/S

If the two generators are in phase (0 degrees) then the voltages track each other. i.e. they are both positive at the same time and both negative at the times time. If you put these generators in series and they are at 0 degrees then the voltage between the two will read zero since they are at the same volts. This is like taking two D cell batteries and put the negatives together. If they are both new, then you will read very close to zero volts between the two positive terminals. What you want is 180 degrees out of phase. So when one is negative then the other is positive. This way the voltages add and you get 240 volts between the two hot legs of the generator. This is like two D cell batteries with the negative of one connected to the positive of the other. The unconnected terminals will have about 3 volts between them.

I hope this helps. Drawings would be better.

 

[dangier_VA]

BobRip-This unit has what I think are voltage regulators that are sealed (no adjustment that I can see).

Going tomorrow to Warrenton, VA, looking to find a machine shop to replace the bearing sleave.

 

[BobRip]

BobRip-This unit has what I think are voltage regulators that are sealed (no adjustment that I can see).

Going tomorrow to Warrenton, VA, looking to find a machine shop to replace the bearing sleave.

Can you talk to the manufacture? Sometimes things that are sealed don't have to stay that way, but I bet they are alright.

If the voltage on each generator is 1/2 of the total voltage then you have it set up right.