Microwave won´t run on inverter

karoja · Post by **karoja** » Thu Apr 16, 2009 6:52 pm

I posted this also on the Yahoo group, hope you don´t mind teh repost here:

I have a ML1500-24, 24 Volt DC to 110 Volt AC power inverter, 1500 watts
continuous, 3000 watts peak installed in my Pinzgauer 712 camper, and enough power in my battery bank to run it. However, when I plug in the microwave (700 watts) not even the clock will come on. I understand the inverter puts out a square sinus curve. Could this be the problem? Any suggestions which brand of microwave to use?

Thanks in advance, Karl

russ · Post by **russ** » Thu Apr 16, 2009 10:34 pm

Modified sine wave inverters work with most appliances but not everything. I have a remotely controlled fan which started to melt the case when connected to my modified sine wave inverter. I stopped it before it did any damage. The price of a true sine wave inverter is usually significantly higher.

I haven't run my microwave off the inverter so I don't know if it would have the same problem or not. My refrigerator, TV and cable box work powered from it. You might want to try to run it (check the clock at least) connected to a UPS which you unplug from power. Unless you have a very expensive UPS it should do the same thing. It would take a substantial UPS to actually run a microwave oven so I wouldn't suggest you try to make popcorn.

Here is a link to additional information on the inverter's output: http://www.pcguide.com/ref/power/ext/up ... put-c.html

chacaocop1 · Post by **chacaocop1** » Thu Apr 16, 2009 11:01 pm

Karl:

I really don't know the reason why your microwave does not work. But let me ask you two questions:

Do other appliances or electronics work from the inverter?

Have you tested the MW any other place and verify that works?

If the two answers are yes, then I guess Russ is right on the money...

karoja · Post by **karoja** » Fri Apr 17, 2009 12:48 pm

Thanks for all the kind responses Ruzz, Cacaocop1. I will try it with a UPS later today. The microwave runs with AC power, no problem. What other invertors do you suggest to use? I bought mine form this store, its the 24 volt 15 watt one.

ka · Post by ka » Fri Apr 17, 2009 2:35 pm

dont those things take way more than 15 watts?

Jimm391730 · Post by **Jimm391730** » Tue Apr 21, 2009 12:16 am

I'm using a 1500W Samlex modified sine wave inverter to run a small GE microwave. The only difference I've ever noticed is that the microwave sounds just slightly noisier when run from the inverter.

It must be the electronics in your particular microwave; the actual heating is powered through a "constant voltage" type of transformer that (for the most part) doesn't care how it is driven. But if the clock won't come on the electronics can't close the relay to power the unit. Microwave ovens are (now) cheaper than inverters; try a different brand. I looked for a unit that had the lowest kVA draw with a reasonable Wattage (1100 kVA input, 700 watts heating) to keep from draining batteries as quickly.

Jim M.
712W and 710M

karoja · Post by **karoja** » Tue Apr 21, 2009 10:32 am

Thanks Jim, that is exactly the way I want to go.

M Wehrman · Post by **M Wehrman** » Wed Apr 22, 2009 12:28 am

Karl, Is there a possibility of some sort of mismatch in CPS (cycles per second)? In Europe (perhaps elsewhere)50cps seems the norm,and in US 60 is the favorite flavor. Just a thought,maybe there may be a mismatch between your inverter and your m-wave.
Your avitar pic looks great,please share some photos!
Mark

karoja · Post by **karoja** » Wed Apr 22, 2009 4:40 pm

Hi Mark, thanks for your response. We also have 60 Hz cycle in Guatemala, same as US, so there is no problemn with this. Hope to post some pics soon. Brgds,

karoja · Post by **karoja** » Wed Apr 22, 2009 5:49 pm

Mark, posted some pics under Pinzgauer Trails. Brgds,