Microwave / Generator issues.......

[mikakuja]

I recently acquired a Honeywell (Generac) 2000 watt inverter generator which seems to be in really nice shape, (and a hell of a lot quieter than my big old Champion). The gen starts really easy, puts out 118-120v constant and will run pretty much everything I throw at it with the exception of the A/C, which I expected anyway. For some reason my 900w Dometic RV microwave does not like this gen....... I would have thought that a 2000 watt 2200 peak gen should handle the start up load of this microwave with no real issues. The microwave will run about every half dozen attempts but the gen does have to work quite hard when it does start.. Now I realize that the Generac IX2000 is no Honda and I am certainly not comparing it to one but come on... Am I expecting too much or is it possible that the microwave is on the way out??? It is after all a 97 model year..

I should add that the microwave will run off my 1500 watt inverter, but I really don't like killing batteries that fast....

For those that are going to say it.... Buy a Honda, or a Yamaha, don't waste your time or money on off shore gens..... I already agree with you... I just happen to have this one and would like to stick with what I have for now... Unless you are buying....lol...

Forgot to mention... I have already ensured that everything else in the trailer has been turned off, including the charger, fridge etc.

[Kayteg1]

Are you hoping for 12VDC coming out of generator alternator?
I don't think it is happening. 12V would take serious wiring what would be costly and heavy.
There is a reason why electric cars run on hundreds of volts DC.

[MEXICOWANDERER]

The primary source is most likely not a generator rather an alternator. Rectified 3-phase? If so, it would have to have an exciter for field current. Controlled field current to maintain secondary output. in short, a voltage regulator. If field current was properly controlled, a bummer of an inverter generator could have a "makeover" and become a substantial battery charger.

[Kayteg1]

I have never seen manufacturer giving that spec, but I would suspect like 60VDC.
On my camper, the inverter generator is having pretty big electrical box with fans on it placed in separate compartment.
I am still figuring out if that is inverter or something else.
BTW "inverter" doesn't have to mean DC involved.
Compare inverter welders.
On my house refrigerator inverter takes 120VAC and inverts 50-250VAC depends on need.

[MEXICOWANDERER]

Curiosity Overwhelms Me...

Inverter generators must generate DC, then pervert it to some sort of "60 Hurts", wave-form.

Any idea of what that primary voltage may be?

[Kayteg1]

Sounds to me like the OP has a problem with inverter on his generator.
I have 700W microwave in my camper and it will run with no problems from 800W generator.
Paid $80 for the generator at Harbor Freight and like the 2-cycle better for everyday use, than build-in 3600W gas sucker.

[road-runner]

SoundGuy wrote:
the Honda EU2000i will easily sustain a full 2000 watt surge for a minimum of 1/2 hour.

My eu2000i has never been able to supply 2,000 VA for more than a few seconds at low (~500 feet MSL) elevations with moderate ambient temps. It tops out at about 1,900 VA, and will hold that for a long time.

[VTR]

Makes me glad I bought the smarter tools generator from Costco 4 or 5 years ago.

[wa8yxm]

First, that microwave likely sucks around 12-1500 watts when running, start up is easily 2x that so I'm not surprised, a 750 watt MW can suck 1100 watts running. Where does the rest go, Well heat, transformer loss, the fan and light all suck, watts.. Something as simple as removing the light bulb may work.

Second. if the 1500 Watt inverter does not mind running it.. Well then what converter do you have.. What I am about to describe I have actually done in a campground with low voltage.

I flipped the breaker that sends power to my IN-LINE inverter but left the independent converter powered.. So the Converter (an 80 amp model) charged the batteries almost as fast as the 1100 watt draw Microwave could suck power out of 'em.

Years ago I visited an electronics parts store (my favorite kind of store) and they had a display of a power line conditioner.. The display included a dual trace oscilloscope with input and output waveforms clearly displayed, and a button you could push to dirty up the input.. and I mean DIRTY up the input.. The output remained a perfect sine wave.

The unit consisted of 3 modules.

Input module was a 3-stage converter, not at all unlike my PDI 9180 with wizard
Middle module was a 12 volt Sealed VLRA battery, likely an AGM but I did not look that close (AGM's are easier to transport, can be mounted in ways other than "This Side Up" and so on).. followed by a true Sine Wave inverter output module.

The ultimate in UPS systems I might add, in fact the only true UPS system.

(What they sell as UPS systems there is a very brief interruption in output power when it transfers, this one there would be NO break at all).

What you do when you run the converter on the generator, and let the inverter run the microwave, Is basically this system Which had a rather large price tag, comma and all, by the way.

[GordonThree]

Chris Bryant wrote:
I'm wondering what the waveform is like on those, if it's more modified than sine wave.

I'm guessing it's a modified sine superimposed over the mechanical sine from the generator itself. at low load it's more modified sine and as the load increases to maximum output it becomes a pure mechanical sine from the generator. If it's a digital inverter, the modified sine could have 256, 512, 1024, etc steps, much better than old school analog modified sine that might have only 4 or 8 steps.

if I can find an unfiltered AC to AC wall wart in my junk drawer, I'll hook my Tek up to one of my Yamaha and find out... sometime 🙂

edit: found the link below with lots of technical information on various generator technologies used by Honda
http://www.screenlightandgrip.com/html/emailnewsletter_generators.html

[pianotuna]

2000 va is not the same as 2000 watts.

Change the inverter for a hybrid unit.

[Chris_Bryant]

I'm wondering what the waveform is like on those, if it's more modified than sine wave.

[Sam_Spade]

mikakuja wrote:
For some reason my 900w Dometic RV microwave does not like this gen....... I would have thought that a 2000 watt 2200 peak gen should handle the start up load of this microwave with no real issues. The microwave will run about every half dozen attempts but the gen does have to work quite hard when it does start..

What exactly happens when it "fails" ??

If the surge of the MW starting is just a bit more than the gen can handle, replacing either will probably solve the problem.

[GordonThree]

MW might have poor power factor and that's what the gen doesn't like. Put a killa-watt meter on the MW and see what it says about watts and PF.

[morphrider]

Have you tried any other generator? what elevation are you at as well? My champion will not run my microwave or AC while we are camping up around 9500'. I talked to Champion rep who stated elevation plays a factor on generator due to air density. True fact or not I do not know other than I only use my generator now to charge batteries in TT while brewing coffee...

[SoundGuy]

mikakuja wrote:
Am I expecting too much or is it possible that the microwave is on the way out???

No 2K inverter genset on the market with the exception of the Honda EU2000i has a particularly good surge capability. Even the Yamaha EF2000iS is lucky to sustain 20" at 2000 watts while the Honda EU2000i will easily sustain a full 2000 watt surge for a minimum of 1/2 hour. You can bet this Generac suffers in the same manner. I've never had any issues starting any microwave oven we've owned with an EU2000i which barely blinks when the MW starts up. :B