# RPM to produce power.



## Jeffro2015 (Dec 29, 2020)

Hello, I have an old unmolested generator that I know little about. It had a throttle "lock" on it where I see it has been removed which to me sends up a red flag. When started I can idle it down and it produces no electricity. When revved up I can get it to produce 120V and 220V. To me it seems like it's winding pretty tight since it's 3/4 throttle. Its a big 20hp motor I figured it wouldn't need so many RPM's. Also I can rev it more and it puts out over the 120V and 220V. Does anyone know if I have a normal generator or do I have issues? Thank you!


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## Jump (Nov 19, 2020)

delete

Jump


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## drmerdp (Apr 10, 2018)

3600 RPMs are necessary to produce proper power. Its not something that can be idled down. You have a standard 2 pole alternator.

Only inverter generators can run at less then 3600 rpms and produce 120/240v @ 60hz.


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## jkingrph (Sep 18, 2017)

I have a Honda EB11000 with I think that same engine. Specs on that engine show it puts out the rated hp at 3600 RPM.

Mine has a eco mode, where it does slow down under very light loads, I honestly have not checked voltage or HZ when it is slowed in econo mode. The minute it senses a load it revs back up.


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## Jeffro2015 (Dec 29, 2020)

jkingrph said:


> I have a Honda EB11000 with I think that same engine. Specs on that engine show it puts out the rated hp at 3600 RPM.
> 
> Mine has a eco mode, where it does slow down under very light loads, I honestly have not checked voltage or HZ when it is slowed in econo mode. The minute it senses a load it revs back up.


Thank you for the reply. since yours has eco i think our situations are not comparable. I will try to check the rpms though.
thanks again.


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## Jeffro2015 (Dec 29, 2020)

drmerdp said:


> 3600 RPMs are necessary to produce proper power. Its not something that can be idled down. You have a standard 2 pole alternator.
> 
> Only inverter generators can run at less then 3600 rpms and produce 120/240v @ 60hz.


Thank you for the input. she sure sounds more like 5000 or so before it produces. Should it be able to overproduce like mine does? It's possible that the 220V is the sweet spot at 3600. I wioll have to try to find out how to check rpms. any other suggestions is sure appreciated. thank you!


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## Matt88-8 (Dec 27, 2018)

Jeffro2015 said:


> Thank you for the input. she sure sounds more like 5000 or so before it produces. Should it be able to overproduce like mine does? It's possible that the 220V is the sweet spot at 3600. I wioll have to try to find out how to check rpms. any other suggestions is sure appreciated. thank you!


Don't mess around with sound. Check the HZ at the plug. If you don't spin the generator at 3600rpm you won't make 60HZ you likely have a automatic voltage regulator so voltage won't be a good way to measure anything.

Sent from my SM-G973W using Tapatalk


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## iowagold (Jan 22, 2020)

amen matt!
ok op here is what to do!
yup load up the gen a bit with 2 1500 watt 120 vac space heaters one on L1 and the second on L2
the throttle on these gens should be fixed speed with a gov for load speed control.
set the gen speed at 60hz
no load should be 61 hz max full load should be 59 hz
the v twins most of the time do not have an eco mode like on the inverter units.
they are a construction gen set... so they act different under super low or no load.
if you are to use one of these for home back up make sure to do all of the proper stuff for proper connection.
and do not run them in the construction site eco mode.


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## BobS (Aug 26, 2020)

I have the tri-fuel version (approx 17 years old). There is no eco mode. Set the rpm's to 3720 or 62Hz for no load. It should be approx. 60 hz (3600 rpm) at half load (approx. 5-6 kw). If you use the generator near its max. load, you may want to increase its no load rpms to 3780 or 62.5hz as the hertz decreases as the load increases especially if you are using battery backups (UPS) in the residence. Most UPSs work within a narrow range of hertz (usually 62.5 to 59).


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## Jeffro2015 (Dec 29, 2020)

Matt88-8 said:


> Don't mess around with sound. Check the HZ at the plug. If you don't spin the generator at 3600rpm you won't make 60HZ you likely have a automatic voltage regulator so voltage won't be a good way to measure anything.
> 
> Sent from my SM-G973W using Tapatalk


Thank you Matt very good information and much appreciated.


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## Jeffro2015 (Dec 29, 2020)

iowagold said:


> amen matt!
> ok op here is what to do!
> yup load up the gen a bit with 2 1500 watt 120 vac space heaters one on L1 and the second on L2
> the throttle on these gens should be fixed speed with a gov for load speed control.
> ...


thank you IOWAgold for the detailed information. I will print this and save it. I'm n ot where the generator is but I will sure use it once I get back home to dial it in.


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## Jeffro2015 (Dec 29, 2020)

BobS said:


> I have the tri-fuel version (approx 17 years old). There is no eco mode. Set the rpm's to 3720 or 62Hz for no load. It should be approx. 60 hz (3600 rpm) at half load (approx. 5-6 kw). If you use the generator near its max. load, you may want to increase its no load rpms to 3780 or 62.5hz as the hertz decreases as the load increases especially if you are using battery backups (UPS) in the residence. Most UPSs work within a narrow range of hertz (usually 62.5 to 59).


Thank you BobS. Your information is priceless! You guys are unbelievable. Thank you so much for taking the time to give me such a precise and detailed answer!


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