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stevensuf 16-06-2012 09:53

Microwave on inverter??
Have a strange one, I have a 2000w pure sine wave inverter, tested it with various things works ok, 2kw heater powered ok, but for some reason it doesnt like powering an 800w microwave?? any ideas?

svHyLyte 16-06-2012 10:48

Re: Microwave on inverter??
What doesn't seem to like what? We have a Heart 2KW inverter/charger that powers an Origo microwave without difficulty so I'm mystified as to why your system doesn't seem to work.

stevensuf 16-06-2012 11:05

Re: Microwave on inverter??
Me too, It comes up with some sort of fault alarm, then resets itself, plug in 2kw heater no probs, ice maker fine, hairdryer fine, 800w microwave and it has a heart attack, wondering if there is maybe some sort of interference?

svHyLyte 16-06-2012 11:39

Re: Microwave on inverter??

Originally Posted by stevensuf (Post 971801)
Me too, It comes up with some sort of fault alarm, then resets itself, plug in 2kw heater no probs, ice maker fine, hairdryer fine, 800w microwave and it has a heart attack, wondering if there is maybe some sort of interference?

So it is the inverter that times out/resets? Do you still have the owner's manual for the microwave? I wonder if there is a surge required for the magnatron to get it activated that might cause a problem with the inverter/be read as a short? Might be worth trying another microwave just for the heck of it, eh?

stevensuf 16-06-2012 11:54

Re: Microwave on inverter??
I don't know its strange, i cant find the manual for the inverter, it beeps for about ten seconds with the fault light on, all the while the microwave is working fine, then resets itself, might be something to do with the magnetron, or perhaps some sort of ground fault or the like...

CharlieJ 16-06-2012 15:44

Re: Microwave on inverter??
Does the microwave work properly when on shore power or ship's power?


David M 16-06-2012 16:12

Re: Microwave on inverter??
How many amps at 120V does it draw? The power the microwave produces is going to be less than the power it draws because it is not 100% efficient. My thousand watt microwave draws almost 14 amps at 120V. I can't let it draw just from the batteries alone because it will draw them below 12 volts in a couple minutes, and I have three 8-D house batteries.

deckofficer 16-06-2012 16:15

Re: Microwave on inverter??
On a similar note I also have the Trace 2012 and a Honda 1000 watt inverter style generator. When running the Honda to charge batteries through the Trace, I have to set a much lower charge rate on the Trace, only 20 amps. Math says the Honda should allow the Trace to charge at least 60 amps, but even on 40 amps it causes the Honda's inverter to fault.

tpkas 16-06-2012 16:30

Re: Microwave on inverter??
Similar problems also. Had an LG microwave, 700W output and the decal on the back indicated a 1000W input. When we tried it the battery monitor showed a current discharge of 110amps which translates to a little over 1300W ... inverter capacity is only 1200W and so it tripped off .... then we tripped off back to the store and returned the microwave! :banghead: Think we'll give up on the idea of a microwave on board.

Mr B 16-06-2012 17:19

Re: Microwave on inverter??
it might be the micro wave itself giving you problems,

I had an 1800 watt invertor and it ran my micro wave with no problems at all.

I dont know what the microwave was, as I no longer have it, it got drowned,

Is your invertor a Pure sine wave or Modified Sine wave,

Modified sine wave invertors dont run a lot of things,

You did say yours is a pure sine wave, But check it out to make sure it is a pure sine wave. Not modified,

colemj 16-06-2012 17:19

Re: Microwave on inverter??
Two possibilities: either your battery voltage is being brought down below the inverter cutoff or it is a modified sine wave inverter that is not large enough for an inductive load. A MS inverter has a much lower efficiency for inductive loads like a microwave and so may be having a problem running it. MS inverters have no problem with resistive loads like hair dryers, heaters, etc.

Check your battery voltage at the inverter when it is running to see if it drops below the low voltage cutoff and put a clamp on ammeter on the AC line to see what power the microwave is actually drawing from the inverter.


stevensuf 17-06-2012 00:28

Re: Microwave on inverter??
The inverter is a pure sine wave, i have 500ah of agm and two 2 gauge cables running to the inverter, the battery voltage drops very little when running the 2kw blower heater, granted this is almost a pure resistive load. I have kept the cable run very short, less than 2 foot.

I'll need to wait till i have someone else aboard to measure the drop on the microwave, kinda hard to do on my own as it resets within ten seconds.

svBeBe 17-06-2012 01:20

Re: Microwave on inverter??
Purely a guess. First turn on something else that draws power; then turn on the microwave.

We have 1800w Prosine inverter and it operates a 900w microwave (240v 50 hz) just fine, but the microwave in stand-by mode does not draw enough power to remain powered by the inverter; and the inverter immediately goes into sleep mode. If I first turn on the printer or some other small appliance drawing power from the inverter, then the inverter has enough draw to keep it in active mode when the microwave is in stand-by mode. Then the microwave works just fine with no error codes on either microwave or inverter.


colemj 17-06-2012 06:17

Re: Microwave on inverter??
Sounds like your inverter should run the microwave with no problem. Does the microwave work on shore power? Luckily, small microwaves are so inexpensive that you can always troubleshoot by simply buying another and seeing if it works. Return it if it doesn't and try another!

And sorry about asking if it was a modified sine wave inverter - I just saw that you specifically stated it was not in the opening post.


Entlie 17-06-2012 06:22

Re: Microwave on inverter??
I have ruined one microwave running it on an inverter, and the one we have now (different brand, low wattage), trips most of the time unless I want to juice a lime or a lemon for 10 seconds. It runs fine on 110, so whenever we want to use it, we just turn on the generator.

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