Community Forums

slddnmatt · 02-27-2021, 10:11 AM

Trying to figure this out. 99 Ultimate Freedom, generator is an Onan 7500 QD. When running the microwave (850 watt) it will shut off here and there. I’ll have the fridge on gas, inverter is a 2000 watt. So there is the batteries being charged to add to the usage. We won’t have multiple things plugged in and going at once and the sucker will turn off. What am I missing???

Ljwt330 · 02-27-2021, 10:22 AM

Quote:

Originally Posted by slddnmatt

Trying to figure this out. 99 Ultimate Freedom, generator is an Onan 7500 QD. When running the microwave (850 watt) it will shut off here and there. I’ll have the fridge on gas, inverter is a 2000 watt. So there is the batteries being charged to add to the usage. We won’t have multiple things plugged in and going at once and the sucker will turn off. What am I missing???

It's not clear as to under what circumstances the microwave shuts off, and whether or not it comes back on without you resetting something. For example, is the micro being used with the inverter only, or is the generator also running when the shut off happens? Do you need to reset anything to get the micro to come back on?

Personally, I couldn't figure out the situation you describe. If the micro shuts off when on inverter only, it's probably a battery issue and the inverter automatically shuts down the AC. How old are your batteries? If the micro shuts off when you have the generator running, something else is going on as the gen should be supplying 120v AC directly to the micro.

slddnmatt · 02-27-2021, 10:45 AM

Just boondocking with the Generator running. No issues when plugged into shore power. Microwave will turn off, acts like the generator is over burdened I guess and will turn the microwave off. Will have to hit start again.

twinboat · 02-27-2021, 11:36 AM

You may need a fuel filter on the generator, if its stumbling under load.

Have you tried turning on an AC or electric heater with generator running ?

**CountryFit** · 02-27-2021, 11:47 AM

Without knowing the details about your microwave, a likelihood of the cause is that your microwave draws too much current (faulty) dragging down the voltage that triggers the ATS' low voltage protection.

I'd suggest troubleshooting from here -
Measure the wall outlet voltage (where mw plugs in) with a voltmeter (a function of multimeter) to detect if the voltage is suddenly dropped to below than 90v before the mw off. (Also observe if the power is back within 2-4 minutes after the incident.)

This will tell you the probable cause of the problem on mw or a weak genset.

Unplanned Tourist · 02-27-2021, 12:53 PM

Do you have an ATS (Auto Transfer Switch) in your inverter system? It may not be transfering over to the power from the genset, and battery voltage is dropping enough to shut down the inverter. Watch your battery voltage as you run the microwave.

Just a guess.

Terrapin · 02-27-2021, 12:53 PM

2000 watt inverter may be the surge rate, 1600 constant is avg if thats the case. my "800W Microwave" uses 1300W input (max), yous will be even higher likely. Add propane refig. solenoid wattage, plus lighting, safety monitors like CO and propane. parasitic lodes from all led indicator lights, standby on electronics and losses due to distance of wiring and older connections getting a little tarnished mean what may have worked won't now... It sounds pretty very close to maxxed out....

A simple step up to a pure sine wave 2500w inverter. may do the trick.

or..

Panasonic sells inverter microwaves that draw less current vs the cooking output. They are popular among solar campers for that reason.

slddnmatt · 02-27-2021, 04:19 PM

Voltage stays at about 118.6 measured at the wall. Drops to 114.6-114.8 with microwave running. Microwave is a sharp 1850-A convection oven. Load rating on my AC line 4 and 16 when microwave is running

curtsr · 02-27-2021, 05:00 PM

Are you shore its not a problem with the microwave? Try keeping your meter connected to the outlet and see if the voltage drops when the microwave stops. If the voltage doesn't drop it is probably a problem with the microwave.

slddnmatt · 02-27-2021, 05:32 PM

Voltage stays fine. We can be running the tv or whatever and maybe turn on something else like the water heater and it might kill the power to the appliances. Generator runs great

FIRE UP · 02-27-2021, 07:29 PM

Ok,
Let's analyze this.

1. You say you have no issues with the microwave when you're on SHORE POWER, correct?
2. When your gen is running, it's the same as shore power. Your micro SHOULD NOT BE ON THE INVERTER when the gen is running. The gen provides 120VAC, through whatever kind of transfer switch you have, to the 120VAC panel. From there, it goes to all the outlets, just like shore power.
3. Have you *timed* the microwave shut-down, from the start when you push the START button, to the time it shuts down?
4. Does it shut down at or very near, the same amount of time it's been running, each time it shuts down?

There have been a few microwaves, such as the one we have, that is a microwave/convection over, that had the infamous *59 second* disease. That is, we'd hit the START button and, it would cook whatever we had in there, for 59 seconds, EVERY TIME! And then it would shut down. Hit the START button again, and it would shut off at 59 seconds.

Well, a tad bit of research on here, revealed that we were not alone in this dilemma. There is/was a cure for this disease. It was about, oh I don't remember but, maybe somewhere around $39 or so for a specific part. Once that part was installed, all was/is well again and it cooks for whatever length of time we program it to.

Now, is this your problem, not a clue. But, as I asked, does it shut down at the same amount of time from the START, to the point of shut-down, each and every time?
Scott

HarryStone · 02-27-2021, 07:30 PM

When you say the microwave shuts off, do you mean it stops cooking, or the display goes blank? There is a difference. You indicated that you just need to hit start again, which indicates a problem with the microwave, and not the power going to it.

slddnmatt · 02-27-2021, 08:34 PM

It’s not consistent as far as time. When I ran it earlier to watch it, I put it on for 3 minutes. Turned off in a couple minutes. Next time I ran it for 5 and it ran the whole 5 minutes..��*♂️

Ray,IN · 02-27-2021, 09:07 PM

Quote:

Originally Posted by Layton1950

2000 watt inverter may be the surge rate, 1600 constant is avg if thats the case. my "800W Microwave" uses 1300W input (max), yous will be even higher likely. Add propane refig. solenoid wattage, plus lighting, safety monitors like CO and propane. parasitic lodes from all led indicator lights, standby on electronics and losses due to distance of wiring and older connections getting a little tarnished mean what may have worked won't now... It sounds pretty very close to maxxed out....

A simple step up to a pure sine wave 2500w inverter. may do the trick.

or..

Panasonic sells inverter microwaves that draw less current vs the cooking output. They are popular among solar campers for that reason.

Ultimate Freedom MH's came with a Xantrex RS2000 pure sine wave inverter, 2000W is constant output, surge is 3000W. I too suspect the genset is the root cause.