PTO Generator Question

[Harvest Moon]

A few months ago, I was planning ahead and purchased an old WinPower 12pt2 PTO generator.

Last week, I was glad I did. The power went out, I hooked up the generator and everything seemed to work well (sump pump, fridge...) Just for kicks, before putting it away I decided to check the Hz. They bounce between 114 and 134?!?! Power supply from the utility co. on the same meter reads from 59.9 to 60.1.

What does it mean?

 

[eatenabean]

I would use the meter on the generator to see what rpm to run my tractor at. Start your tractor out at a low rpm see what Hz you are at. Then slowly raise your rpm till your generator is at 60 Hz. Once you are at 60, I would load it again to see where it drops to and raise it back to 60.

 

[Harvest Moon]

It bounces between 30 Hz and 60 Hz at idle. I get a nice even 130 +/- 1.5 volts at 540 per the tach. But the notes above are based on the generator running at 125 volts.

Is this some kind of noise thing messing with the accuracy of my digital meter? Or is there some kind of short or something doubling the frequency?

 

[eatenabean]

The one thing I don't get is the Hz jumping from 30 to 60 Hz. The name plate said at 1800 rpm you should have 60 Hz. So for the Hz to be jumping from 60 to 30, you would have a 900 rpm swing. The Hz should be as steady as your tractor speed. Do you hear any surging like that.

 

[eatenabean]

One other thing. Where your pro shaft hooks up, is that gears or belt drive?

 

[Harvest Moon]

No surging, the tractor is in great shape and slightly oversized. It runs smooth and doesn't flinch, even with changes in load.

Just plugged in the old shop vac. to load it up a little and the Hz jumped to 172 -194 range.

I'm hoping it's the meter, but it still reads 59.9 to 60.1 on utility co. power.

 

[Harvest Moon]

Generator has a gear box with gear oil, not sure if there is a chain in it or not. Tractor PTO is all gears. It's all metal.

 

[eatenabean]

Have you tried different reading points, phase to phase, phase to ground.

 

[Harvest Moon]

I'm not that sophisticated but I think so. Tried hot to ground, hot to hot on the 240V receptacle and each hot to neutral/ground.

It reads over 400 Hz on one of the hots to neutral/ground on the 240V.

When it was all set up, my neighbor and I shared a spider box with GFCI breakers on it to distribute the power. The breakers didn't trip. Used both hot legs. No equipment problems at all.

So I think I have more refined questions:

1) Is it really possible to run a sump pump, fridge and even a TV if I really have 120+ Hz? Something would break, right?

2) So it's probably the meter? But what does that? Is it noise/interference?

3) But wouldn't that mess with the TV? The TV was very clean.

Thanks for all of your help and interest BTW!

 

[kennyd]

What are you using to test frequency?