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WHAT makes an Inverter Gererator so special. ???

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gary350

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Years ago I never heard of an inverter generator.

20 years ago I bought a 6000 watt generator to run the house after storms made electricity go off. Sometimes power was off for 2 days. Generator still runs like new its only been used about 5 times.

What makes an inverter generator different than this old generator I have?
 

gary350

Well-Known Member
The way I understand it is, gas engine turns a DC generator, the electronic inverter turns DC to AC. OK I under stand this.

On the RV camping forum 99% of the people claim, you must have an inverter generator the old construction generators will burn up every appliance you have. I tell people I have been running my house and RV on this old generator for 20 years they all think I am crazy or own drugs. They claim an AC construction generator will burn up a microwave or TV in 30 seconds then I tell them I been doing it 20 years they think it is a lie. They keep telling me, YOUR NOT DOING THAT........THAT IS NOT TRUE. Ok I understand no more questions.
 

shortbus=

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Aren't they like a generator and single phase VFD in one? That way the engine speed isn't as critical to the output frequency.
 

KeepItSimpleStupid

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Aren't they like a generator and single phase VFD in one? That way the engine speed isn't as critical to the output frequency.
Engine speed should not affect output frequency.

I had to pick a UPS for a PLC system that would keep the PLC operating while the generator kicked in. It does not appear to be well known that the frequency variation of the UPS input affects the UPS. Manager was complaining about cost.
 

MikeMl

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You wouldn't be asking the question if you have to sleep next to an inverter vs a conventional generator.

You wouldn't be asking the question if you have to buy gas for an inverter vs a conventional generator.
 

sagor1

Active Member
Also, many inverter generators have connections to allow parallel operation with another inverter generator, thus doubling its capacity. This can only be done because while the motors each generate the DC enough for one, the DC can be shared between two inverters regardless of loads. You cannot do that with motor driven AC alternators, the slightest difference in motor speed makes a difference in phase angle of the AC, and you cannot parallel them for higher loads.
 

crutschow

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Regular alternators have to keep running at a constant speed to maintain a constant power output voltage and frequency.
Thus, even if it's only powering a 10W bulb, it's still running at that high speed.

An inverter generator delivers a constant output frequency and voltage independent of the motor speed (within limits), so the motor can slow down for light loads and only has to run at the maximum speed when fully loaded.
Thus, noise and gas consumption are significantly reduced for light loads, compared to a standard AC alternator.
 

dknguyen

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Regular alternators have to keep running at a constant speed to maintain a constant power output voltage and frequency.
Thus, even if it's only powering a 10W bulb, it's still running at that high speed.

An inverter generator delivers a constant output frequency and voltage independent of the motor speed (within limits), so the motor can slow down for light loads and only has to run at the maximum speed when fully loaded.
Thus, noise and gas consumption are significantly reduced for light loads, compared to a standard AC alternator.
Does a non-inverter generator have issues with overvolting when it's at high speed while being underloaded? If so, how does it deal with it?
 

shortbus=

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Engine speed should not affect output frequency.
It does on a standard non invert alternator. Which is what these really are ,though they are called 'generators'. Run one under the set speed and frequency is too low, over speed and it is to high. On older worn 'generators' the worn throttle linkage/governor will not keep things quite right. But for most things it's acceptable.
 

AnalogKid

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Does a non-inverter generator have issues with overvolting when it's at high speed while being underloaded?
No. A non-inverter generator runs at a constant speed regardless of load, much the same way a car on cruise control runs at a constant speed regardless of its weight, going uphill vs leval ground, etc. A mechanical or electronic governor modulates the carburator to keep the shaft speed near-constant.

Speed regulation in a non-inverter gen has nothing to do with output voltage, and everything to do with output frequency. The output freq is directly proportional to engine RPM. On mine, the engine runs at 1800 RPM and a 2-pole generator puts out 60 Hz (3600 cycles/minute). The output voltage sags a bit with increasing electrical load, but that is due to wire size in the generator.

ak
 

gary350

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Engine speed will never effect the frequency. Generator is DC no matter what speed the motor runs the inverter makes 60 Hz. Engine runs only fast enough for generator to make enough power to run the load. Output 120vac stays the same only the amps change.
 

crutschow

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1800 RPM and a 2-pole generator puts out 60 Hz (3600 cycles/minute)
I believe you mean 4-pole.
The minimum is 2-poles, which requires 3600 RPM for 60Hz out.
 

AnalogKid

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Engine speed will never effect the frequency. Generator is DC no matter what speed the motor runs the inverter makes 60 Hz. Engine runs only fast enough for generator to make enough power to run the load. Output 120vac stays the same only the amps change.
If you are responding to my post #15, I was describing a *non*-inverter generator.

ak
 

gary350

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Yeah, I meant two pole sets. I don't often write about motors or generators, so I'm not as up on the lingo.

ak
What are poles? I took my 5KW generator apart once, like most generators it has 2 windings on the armature and 2 windings on the stator. I know some generators have more than 2 windings. I have another generator with 6 windings.
 
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