Generator Electrical Engineering Question

[Soundguy]

used to make a big difference to tv's and monitors.. but now not so much.. heck.. even a while back you got the ones that worked on 50-60cps.

soundguy

 

[mbohuntr]

This has been a very interesting thread, I learned a lot!! :thumbsup:

 

[dangier_VA]

Me Too!! Thanks to all that replied! Vast database of information and experience on this board. Keep up the great work!
David

 

[Redneck in training]

Exactly. If you ever been to a grid distribution center, the frequency fluctuates more or less, same for voltage.

Power distribution actually counts number of periods per in example a day and makes them the same every day. If the grid runs slower during the peak it will run proportionally faster during the light load to make it up. The difference is fraction of Hz.
Do you rmeber the old synchronious motor clock? they were prety much exact over long term but somewhat off during certain part of the day.

 

[mbohuntr]

I work at a power generating station, and I find it fascinating how the speed and phases are aligned to connect to the grid. Then there is power factor correction, and protective schemes to be considered. The subject seems to be endless. Tesla was a genius...

 

[Steve_Miller]

Then there is power factor correction, and protective schemes to be considered. The subject seems to be endless.

I don't like this at all, causes all sorts of weird and wonderful things that no one can prove when something happens to your equipment.

Steve

 

[dangier_VA]

Got a chance to put the generator back together and test run it on a load bank. Overall the results are pretty good.

No load---59 cycles---127.9/125.1/253 volts
5000 watt load---58.4 cycles---118.8/120.1/239.0
10000 watt load---57.3 cycles---117.6/118.4/236.2

I then went back and adjusted the rpm to check voltage at each load and got the following:

5000 watt load---58.8 cycles---121.9/123.2/246.1
10000 watt load---59.0 cycles---120.5/121.7/243.3

There is 1 volt difference in the combined voltage when I tried to maintain 59 cycles, where it is not there when I let the voltage (rpm) drift down under load. Not enough of an engineer to know what is causing that.

Although this is a 15,000 watt generator, it would not see anything in the 10,000 watt range. Doubt the tractor would support much above 12,000 watts either (L3130). Have a new APC 550 watt ups and it seemed to like it and went online. Have not checked it with the APC 1550 watts yet.

This generator is old, heavy, and seems built well. There is a flywheel affect with varying loads. The main bull gear in the speed increaser is 3" thick,14" in diameter, and is about 50 pounds. It rides through better than a Coleman 6500 watt gas generator I used a while ago. When loads started or stopped, the voltage fluctuated all over the place. The lights went bright and dim a lot. I like most old equipment over new-built to last!

All this is with the heads 180 degrees out. Oh, and with no bearing noise! Good for another 50 or so years....
Comments?
Thanks,
David

 

[Soundguy]

any way to up the governed rpm so frequency is correct?

soundguy

 

[luscsmith]

With all of this knowledge on board I have two questions.
How are all of the generators that are on the grid put and kept in phase?
What is RMS? Root means square, Root and square of what?

Many Many Thanks, Scott

 

[luscsmith]

One more thing, discussions like this are one of the reasons I do read TBN.

Scott