Author Topic: Engine speed and Hz  (Read 1352 times)

glort

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Re: Engine speed and Hz
« Reply #15 on: June 09, 2018, 12:35:30 AM »
So the generator might have been designed to run at 3600 rpm and 60 Hz?

They are designed to do either one. It's just a matter of how fast you spin the engine.  You have 50Hz in your country, you spin at 3000. You have that Funny American power type system, you spin it at 3600.
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Johndoh

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Re: Engine speed and Hz
« Reply #16 on: June 09, 2018, 12:38:45 AM »
If your loads/equipment are designed to run at 50 hz then set the generator up for 50 hz.

Everything in the house that I have looked at says either 230, 240 or 220-240 V 50 Hz. I changed the position of the governor spring and the revs are just a whisker over 3000 RPM voltage is 234-235 volts and its a bit less noisy since I slowed it down. I like this generator because it was cheap and 5kv ish its got useful power more than I'd need. Because it has more power than the other generators Id like to connect it to the house via a proper changeover switch.
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Johndoh

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Re: Engine speed and Hz
« Reply #17 on: June 09, 2018, 12:46:08 AM »
Thanks Glort I will take your advice. My other generators are capacitor controlled and if I increase the revs I increase the voltage and Hz even I know this isn't regarded as a good idea.
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broncodriver99

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Re: Engine speed and Hz
« Reply #18 on: June 09, 2018, 01:15:28 AM »
I changed the position of the governor spring and the revs are just a whisker over 3000 RPM voltage is 234-235 volts

Sounds like where it should be. You set them to run a little fast at no load and once you add a load it should settle down to where it should be. As you load it up close to maximum you will see it drop a little more. Ideally if it has a good governor you should run about 51 hz no load, be dead on 50 hz about half way loaded up, and it may droop to 49 hz when you get up to full load. Your voltage will do the same thing.

broncodriver99

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Re: Engine speed and Hz
« Reply #19 on: June 09, 2018, 01:35:07 AM »
You have that Funny American power type system, you spin it at 3600.

Don't forget American Samoa, Anguilla, Antigua and Barbuda, Aruba, British Virgin Islands, Bahamas, Belize, Bermuda, Brazil, Canada, Cayman Islands, Colombia, Costa Rica, Cuba, Dominican Republic, Ecuador, El Salvador, Guatemala, Guyana, Haiti, Honduras, Japan, Liberia, Marshall Islands, Mexico, Micronesia, Montserrat, Nicaragua, Palau, Panama, Peru, Philippines, Puerto Rico, Saba, Saint Barthélemy, Saint Kitts and Nevis, Saint Martin, Sint Eustatius, Sint Maarten, Saudi Arabia, South Korea, Suriname, Tahiti, Taiwan, Trinidad & Tobago, Turks and Caicos Islands, United States Virgin Islands, and Venezuela.

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ronmar

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Re: Engine speed and Hz
« Reply #20 on: June 09, 2018, 06:33:54 AM »
Typically the only things really frequency sensetive are those things that use frequency for timing.  Induction motors are one such item so will run at a different RPM with a different frequency applied.  This might cause issues if their end load is not prepared for the higher RPM, such as blower impellars not able to accept the added centrifugal force... or the motor at a reduced RPM might not deliver enough torque to maintain the mechanical load and overheat.

With todays global markets, most electronics use switching mode power supplies to make the DC used by the device from AC.  As mentioned Most all have become universal and will accept 100 to 250 VAC at just about any frequency, so the plants are not making specific products for specific markets.

If your generator speed is mechanically governed, it will probably vary a little more than 1-2 HZ from no load to full load as mechanical governors MUST droop in RPM in order to increase the throttle as the load increases.  My slow speed listeroid runs at a little over 600 RPM with around a 3:1 belt drive ratio which delivers 1800 RPM and 60 hz with a 4 pole generator head.  I set it for 62HZ no load and it droops to right around 58HZ at full load.  More than acceptable for residential power...
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Johndoh

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Re: Engine speed and Hz
« Reply #21 on: June 09, 2018, 09:14:10 AM »
I changed the position of the governor spring and the revs are just a whisker over 3000 RPM voltage is 234-235 volts

Sounds like where it should be. You set them to run a little fast at no load and once you add a load it should settle down to where it should be. As you load it up close to maximum you will see it drop a little more. Ideally if it has a good governor you should run about 51 hz no load, be dead on 50 hz about half way loaded up, and it may droop to 49 hz when you get up to full load. Your voltage will do the same thing.

I think it's not far away 1% is 30 RPM. I don't think a mechanical governor is going to be extremely accurate. This is holy catholic Ireland so everything thats done officially is done half assed my home generated power may well be better than what the grid sells me. Our power needs would be quite small, 2 or 3 low energy bubs, television, fluorescent light, there is a well pump its 1/2 HP so probably 4 kw left for the oil boiler and fridge.
It is better to light a candle than to curse the darkness