Portable Generator questions

Greetungs All, I have a small generator (700 watt, 850 surge) that I use to keep the fridge running when the power is out. It is a robust unit made by Robin and is at least 20 years old. It has an accurate analog voltmeter on it. I tested it by comparing to a digital meter and by directly connecting just the meter to the 115 volt, 60 Hz mains. The label says that the generator puts out 60 Hz but when checked with an oscilloscope (TEK 465B) it shows about 50 Hz. Even though the fridge seems to run fine it sounds different than when operating from the mains. The meter on it shows the voltage as being 115 volts and the motor is running at the nameplate RPM. So what could be the reason for the 'scope showing the lower Hz and is there anything I can do about it? This generator uses brushes on a slip ring to energize the field winding and has some type of transistorised voltage regulator. Thanks, Eric R Snow

Reply to
Eric R Snow
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It might have come from Europe or something - doesn't it have a nameplate that tells you what the output freq. is _supposed_ to be?

It might be as simple as an RPM adjust, since the voltage is regulated, but anyone here would need much more information about the unit itself; otherwise we'd just be guessing.

Thanks, Rich

Reply to
Rich Grise

Small generators generally need to be adjusted so that the voltage and frequency are about 5 to 10 percent high with no load. Both will drop under load. I would try setting the engine speed up a bit. I would also suspect the oscilloscope calibration. The frequency cannot be incorrect when the engine speed is correct if it is a direct connected generator.

Don Young

Reply to
Don Young

"Eric OR Snow"

** Test it with an electric clock or clock radio.

See how much time the clock loses over a few minutes.

....... Phil

Reply to
Phil Allison

What would that accomplish above and beyond looking at the signal with an O'scope? I would think the scope would be the preferred method and the clock using the 60Hz as a timbase would be the "I a'int got no scope" option. If his O'scope showed about 50Hz I would think it is about 50Hz.

Jim

Reply to
James Beck

To remove any doubt about the scope calibration, sync the scope horizontal sweep to commercial power, and look at the generator output. When the engine speed is correct, the waveform on the scope should be stable, or drifting very slowly one way or the other.

Reply to
Peter Bennett

"James Beck"

** A scope trace may be out of calibration, maladjusted or misread.

** The clock method is vastly more precise and fool proof.

** Time to improve your thinking - f*****ad.

....... Phil

Reply to
Phil Allison

Phil, Take you medicine.

Reply to
Tom Biasi

"Tom Biasi " = Jerk Off Scumbag

Go choke on a dog turd - cuntbrain.

Reply to
Phil Allison

Peter Bennett wrote in news: snipped-for-privacy@news.supernews.com:

or look at the powerline frequency on the scope, if its ok then the other measurement is likely ok....

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Reply to
me

I'll have to remember these lines for those times when someone disagrees with something I say, maybe, at a party.

You must hang with a tough crowd, Phil, or get beat up a lot. Or, and here is the real deal: with your undersize penis, skinny little chicken arms and receding hairline, you are too chickenshit to have this type of conversation with another real person, so you choose a medium to offend where there is virtually no likelihood of consequences. it's unfortunate for the rest of us that you're such an offensive and antisocial bastard, because what you say seems to have a degree of technical merit.

So sad....

Sorry for the rant, group.

Reply to
Dave

"Dave the Asinine " MeToo" Fuckwit. "

Go choke on a dog turd - cunthead.

Reply to
Phil Allison

May be yes, but it is the tool of choice and BOY would it need to be out of calibration for it to show 50Hz instead of 60Hz.

Huh????? MAYBE, more fool proof, but I doubt more precise. Plus, he can see any distortion in the sine wave. Do that with your clock.

So, someone questions you and they are a f*****ad? OK......

Jim

Reply to
James Beck

"James Beck"

Another congenital moron f****ng up a potentially useful NG.

....... Phil

Reply to
Phil Allison

All you gotta' do is leave. No need to beat yourself up.

Jim

Reply to
James Beck

"James Beck"

Another congenital ASD f***ed moron f****ng up a potentially useful NG.

....... Phil

Reply to
Phil Allison

Please, stop top posting. People will think you are some mean spirited asshole and not the self flagellant that you really are. Now, be an adult and go away quietly.

Jim

Reply to
James Beck

If he could do that, he wouldn't need the Talcum powder! ;-)

--
Service to my country? Been there, Done that, and I\'ve got my DD214 to
prove it.
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Reply to
Michael A. Terrell

"James Beck"

Reply to
Phil Allison

Yep, been in the coin op business for almost 25 years. I make no attempt to hide what industry I work in or what my email or web address is. Why would I? You really need to have your meds increased. Such a spewing of hate and anger EVERY time someone questions something you say. Now, since you are so much higher and mightier than I am you will have no problem holding your tongue and going away like an adult, but no, you will have to respond once again to fulfill your compulsion to get in the last word.

Jim

Reply to
James Beck

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