I have a 1300W microwave (120v) I’m trying to run using my Champion C46540 but the microwave shuts down about 5 to 10 seconds after I turn it on. I know the generator isn’t overloaded running other stuff. It is lightly loaded running a few led and cfl lightbulbs. It runs a fridge and more lights and coffee maker just fine, although was not running any of these when the microwave kept shutting down.I’m using the 4-prong 30R receptacle to power the breaker panel. At only 1300W the microwave should run just fine. What’s going on?

I would suspect a the generator is slowing too much and the frequency is dropping too far below 60 Hz. It could also be dropping the voltage too much. Have you measured the frequency or voltage when it's running? I'd compare it to when it's running the coffee maker as that should be similar sized load. Coffee makers probably don't care much about voltage or frequency. Keep in mind too, if your microwave is rated at 1,300 watts that's usually it's "cooking power". It's actual power draw from the generator will be a couple hundred watts more. That's not enough to make a difference unless you're running other loads at the same time maybe.

That's an old generator. The generator total harmonic distortion (THD) many be too high or the output voltage may be too low. If may be time to replace the brushes. Does the microwave have a loud hum when running?

That model is rated for 3.5 KW continuous, and has an automatic voltage regulator circuit - so it should be capable of powering just about any microwave oven.Microwaves aren't particularly picky about the AC line frequency, so it should still work even if the frequency is a few Hz off.You might try measuring the AC voltage at the same receptacle the microwave is plugged in to - while the microwave is running. Look for excessive voltage drop as soon as the microwave is turned on.

OP: What you posted for connection is not correct. The four pin twist lock is a 120/240 genset output. The 30TT three wire receptacle is 120 volt.The twist lock only has a 240 volt output rated at 14.6 amps. See page 6 of owner's manualYou should be using the 30TT recptacle to get full load from genset.What is shore power connection in your rig?

enblethen wrote:OP: What you posted for connection is not correct. The hour pin twist lock is a 120/240 genset output. The 30TT three wire receptacle is 120 volt.The twist lock only has a 240 volt output rated at 14.6 amps. See page 6 of owner's manualYou should be using the 30TT recptacle to get full load from genset.What is shore power connection in your rig?This makes sense. If you are indeed using the 4 pin connector to a 50A 4 pin RV cord you are only able to use 1/2 of that power for any one of the 120V devices.Our 2000W Honda struggles with the microwave so 1/2 of 3500W would definitely do so.Since your RV doesn't need 240V, using the 30TT will allow all of the wattage at 120V, which in turn can be connected to both legs of the RV via an adapter.

Why won’t my Champion C46540 generator run the microwave?

2112
Explorer II
Jan 07, 2022
enblethen wrote:
Many of the gensets have power to all receptacles. No selector switch.
But this one doesn't. It's either 120 OR 240. Can't have both at the same time. The schematic says so.
enblethen
Nomad
Jan 06, 2022
Many of the gensets have power to all receptacles. No selector switch.
2112
Explorer II
Jan 06, 2022
Yea, its shown in the illustration on page 5 but no mention of it in the operation section.

Step 2 in "Connecting Electrical Loads" on page 10 is misleading as well. It implies both 120V and 240V connectors will have power at the same time. They don't.
enblethen
Nomad
Jan 06, 2022
I must be blind in that eye! Thanks. Wonder why I didn;\'t see it farther in manual, must be blind in that eye! You would think that it would show on page 6.
2112
Explorer II
Jan 06, 2022
enblethen wrote:
2112: where did you find photo you posted?
From the cover page of the manual you provided. I enlarged it. Open the manual. That picture
enblethen
Nomad
Jan 06, 2022
Interesting it is shown in parts but not shown in the control panel. It is also not the the operational control panel information.
2112: where did you find photo you posted?
2112
Explorer II
Jan 06, 2022
enblethen wrote:
I do not see a switch on this genset to change voltage ouputs. Only switches are the circuit breaker push buttons.
Genset manual
Toggle switch, item 58 on the parts list
enblethen
Nomad
Jan 06, 2022
I do not see a switch on this genset to change voltage ouputs. Only switches are the circuit breaker push buttons.
Genset manual
2112
Explorer II
Jan 05, 2022
Gdetrailer wrote:
... partial credit for the nice diagram though
Thanks
I missed one orange line and didn't bother correcting it. I left a switch blowing in the breeze. I got the point across without it
Gdetrailer
Explorer III
Jan 05, 2022
2112 wrote:
Gdetrailer wrote:
2112 wrote:
......
......
You can get a regulated 120V 3500W using the TT30A connector, but ......
Your close, but not quite correct.

When the switch is set to 120V only, both 120V windings are connected in parallel. This means that not only all of the 3500W is available on the 30A RV outlet but the voltage of both windings are fully regulated by the AVR.
First sentence of last paragraph covered that. Maybe it wasn't clear enough? Do I get partial credit for using less words?

No credit for way too many words in the post of yours I quoted, partial credit for the nice diagram though :B

And, yeah, the OP is not the first or last to get bit by this 120/240 combo thing..

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