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predator 9500 inverter voltage output measurement

tarbash2024

Apr 21, 2024
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I bought a predator 9500 inverter generator a few years back.
I am running into a problem with it, it does not run my 240 AC appliance.
I tried measuring the voltage using a multimeter, but the readings fluctuate
all over the map. Same for the 120 ac outlet, even though
i can run power tools using that outlet.
Is this normal for inverter output. What is the best way to measure RMS voltage output of
the inverter. The sam multimeter gives steady readings for my utility power and another generator, although
that generator does not have an inverter.
 

Harald Kapp

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I tried measuring the voltage using a multimeter, but the readings fluctuate
all over the map.
You sure used the AC measuring range?
Did you measure the inverter's output with an attached load, e.g. a lamp? A small load may be required for the inverter to give a meaningful output.
I am running into a problem with it, it does not run my 240 AC appliance.
Has it done so before? Or is this a new aplication never tried before?
 

73's de Edd

Aug 21, 2015
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Do you also have or can you borrow an old school conventional analog / pointer style meter like a Triplett or Simpson.
I'll just bet that family of meter technology / response will then TOTALLY ignore those WILD variances encountered when using a digital type of metering.
 

Delta Prime

Jul 29, 2020
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I'll just bet that family of meter technology
How much do you want to bet?
predator 9500 inverter generator
That is rated for 7,500 WATTS &
That get to you.(This is only an example ) Refrigerator (700 watts), laptop (200 watts), five to 10 lights (250 watts), smartphone charger (20 watts), home security system (100 watts), TV (100 to 150 watts), 10,000-btu air conditioner (1,000 watts). PLUS: Well pump (1,250 watts), sump pump (900 watts), and gas or propane furnace (800 watts) OR ONE OF THESE: 8-inch burner on an electric range (2,000 watts), dishwasher (1,500 watts)
 

73's de Edd

Aug 21, 2015
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I'll just bet that family of meter technology /
Just on that snippet . . . . .
It is SOLELY referring to the METER technology of the Simpsons and Triplets and their dry plate rectifiers AC-DC conversions and the inherent limitations in snail speed response of a moving coil type of meter movement to any fast changing transitions.
 

Bluejets

Oct 5, 2014
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That get to you.
Be careful quoting handling capacity of generators in relation to any motor.
They will draw 4 to 6 times (depending on type) at startup and drag the output voltage down.
Result being the genset sags and the motor never gets away, at worst, burns itself and/or the gen windings out.

As for the genset in question, it was never made clear if it was even capable of producing/running 240V AC.
Any spec sheet available...???
 
Last edited:

tarbash2024

Apr 21, 2024
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You sure used the AC measuring range?
Did you measure the inverter's output with an attached load, e.g. a lamp? A small load may be required for the inverter to give a meaningful output.

Has it done so before? Or is this a new aplication never tried before?
I did some more experimenting. I added a load and the voltage reads steady at about 127 volts per leg now. I guess the inverter doesn't put out a voltage unless it senses a load.
 

tarbash2024

Apr 21, 2024
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Be careful quoting handling capacity of generators in relation to any motor.
They will draw 4 to 6 times (depending on type) at startup and drag the output voltage down.
Result being the genset sags and the motor never gets away, at worst, burns itself and/or the gen windings out.

As for the genset in question, it was never made clear if it was even capable of producing/running 240V AC.
Any spec sheet available...???
The user manual and the outlet states 240 volts ,30 amp output. Uses an lm14-30 connector. They didn't provide a spec sheet on the inverter itself.
 

tarbash2024

Apr 21, 2024
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How much do you want to bet?

That is rated for 7,500 WATTS &
That get to you.(This is only an example ) Refrigerator (700 watts), laptop (200 watts), five to 10 lights (250 watts), smartphone charger (20 watts), home security system (100 watts), TV (100 to 150 watts), 10,000-btu air conditioner (1,000 watts). PLUS: Well pump (1,250 watts), sump pump (900 watts), and gas or propane furnace (800 watts) OR ONE OF THESE: 8-inch burner on an electric range (2,000 watts), dishwasher (1,500 watts)
I measured the amps on my 1.5 hp well pump at steady state. It was about 12amps at 240 volts. I also have a 1.5 hp booster pump. Between the 2 of them they would use most the generator's output. The awg of house wiring is the main limiting factor. I can pump up to 30 amps safely. But I think the generators spec'd at 30 amp probably max out before hitting 30.
 

Delta Prime

Jul 29, 2020
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@Bluejets
You no longer have the privilege of addressing me. Reactive power absorption in larger induction motor starting cycles means it is possible to compensate for In-Rush starting currents, as well as harmonics, using capacitors that includes super caps, that generate reactive power.
Large induction motors are extremely inductive during start-up, and supplying reactive power to these systems may be more effective than supplying energy from the grid.
Large inrush currents occur in several devices such as induction motors and transformers. surges occur in large electromagnetic devices when they are switched on to induce the magnetic field. And the problem is not just at the motor terminals but the entire power bus.
Ignorance is bliss so you won't read this....
Habyarimana, M, Dorrell, D.G & Musumpuka, R (2022) Reduction of Starting Current in Large Induction Motors Energies 15(10) 3848 [online] mdpi.com. Available at: https://www.mdpi.com/1996-1073/15/10/3848
 
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