Found this advice for when running a converter off a generator (including inverter gens presumably)"•Do not run out of fuel! When fuel levels get low the generator will splutter causing the voltage to surge up and down, if this goes too high it will damage components within the Converter"This could easily happen in my case with my P2200 gen that has no fuel gauge, so I am wondering if the advice is correct about the voltage spikes. Must be others on here who might care too.--Also, Mex has suggested doing this on purpose as a timer limit for how long to be in Absorption, so that wouldn't fit with this advice. So what think? Thanks.

I thought inverter gens didn't produce spikes due to fluctuating rpm.

With a conventional generator, the change in RPMs will cause the frequency to shift, and the voltage to vary. Since the RPMs won't increase drastically, I wouldn't expect the voltage to spike high very much. Not so much an issue with an inverter type generator. The waveform is created electronically, and the engine speed varies to meet load demands anyway.I'm not too worried about this. Most RVs with generators have a conventional type, and they quit under load for a multitude of problems. I've been the RV community for a very long time, I've yet to read a post where someone had damage due to a generator unexpectedly shutdown. I have had damage due to a massive power spike (fallen power line) at a campground, but that's a different topic!

Inverter generators do sag the voltage when they run out of fuel. They also do it when they are shut down. My yamaha has a disconnect switch on it. I'd love to use the Pinella remote to do the switch off, before shutting down, but the relay is only rated for 15 amps.

The quote is from what make and model number?

I can’t see a genset with a voltage regulator or an inverter type giving high voltage spikes- not sure about the cheap contractor type that use a capacitor for regulation.The big problem with a voltage regulated set is it is trying to keep putting out ~120 vac, so the voltage regulator is boosting the rotor voltage, while the frequency drops.IOW, I’d be more concerned with the genset than the converter, most of which can handle a wide range of input voltages.

Voltage Spikes as Gen Runs out of Fuel? | Good Sam Community

13 Replies

valhalla360
Navigator
Oct 22, 2019
Sounds like they converter manufacturer is looking for excuses to throw out if a customer comes to complain...

Hey have you ever let the generator run out of gas...you did...well there's your problem and we won't cover it under warranty...regardless of if it had anything to do with the issue.
time2roll
Nomad
Oct 21, 2019
Pretty sure most generators will say to unplug before shut down.
Could just use a space heater on low and monitor voltage. No electronics to harm.
BFL13
Explorer II
Oct 21, 2019
time2roll wrote:
BFL13 wrote:
time2roll wrote:
The quote is from what make and model number?

See answer to question about what gen and why

https://powermaxconverters.com/bowfishing-gear/

Note this is about powering trolling motors mostly ( amps wrt to thrust, etc) so not same as RV battery charging. Some interesting stuff though.
Not buying it. How about an empirical test?

OK, you do it and let us know if your converter fries. :)

I see the advice above to do a cool down for the gen's benefit, so those who run out the gas to keep the carb clean, take note. I assume the cool down is to unplug all loads "early" and then let it run out of gas.
Wild_Bill_888
Explorer
Oct 21, 2019
The answer depends on the detailed design of the voltage regulator circuit. A high quality design will prevent big spikes.

To test yours, plug in a filament type bulb with various loads you normally have and watch for over bright flashes when it runs out of gas.

A compact lightweight generator running at a high power setting has a lot of excess heat stored inside the case. Running out of gas or shutting off with no cool down subjects non power components (rubber, plastics, capacitors etc.) to a temperature spike, aging the equipment.
time2roll
Nomad
Oct 21, 2019
BFL13 wrote:
time2roll wrote:
The quote is from what make and model number?

See answer to question about what gen and why

https://powermaxconverters.com/bowfishing-gear/

Note this is about powering trolling motors mostly ( amps wrt to thrust, etc) so not same as RV battery charging. Some interesting stuff though.
Not buying it. How about an empirical test?
MrWizard
Moderator
Oct 21, 2019
I would not worry about inverter genny
it's been mentioned many times its synchronous generators
And the damage is mainly to the generator, not to converter
DrewE
Explorer II
Oct 21, 2019
Any modern converter should not be harmed by such moderate input voltage changes. It may shut itself off, but that's hardly a problem when the generator is shutting down anyhow. A standard RV generator installation will have the voltage fluctuate and droop when it's turned off, anyhow, and there's not a lot that can be done about that.

Stopping (or starting) under load is a bit rough on a generator and is best avoided for that reason.
BFL13
Explorer II
Oct 21, 2019
time2roll wrote:
The quote is from what make and model number?

See answer to question about what gen and why

https://powermaxconverters.com/bowfishing-gear/

Note this is about powering trolling motors mostly ( amps wrt to thrust, etc) so not same as RV battery charging. Some interesting stuff though.
Chris_Bryant
Explorer II
Oct 21, 2019
I can’t see a genset with a voltage regulator or an inverter type giving high voltage spikes- not sure about the cheap contractor type that use a capacitor for regulation.
The big problem with a voltage regulated set is it is trying to keep putting out ~120 vac, so the voltage regulator is boosting the rotor voltage, while the frequency drops.
IOW, I’d be more concerned with the genset than the converter, most of which can handle a wide range of input voltages.
time2roll
Nomad
Oct 21, 2019
The quote is from what make and model number?

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Voltage Spikes as Gen Runs out of Fuel?

13 Replies

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