sine wave v. modified sine wave

Does anyone have any experience running a microwave oven on a modified sine wave inverter or do they require a sine wave? Thanks


  • crewzercrewzer Registered Users, Solar Expert Posts: 1,832 ✭✭✭✭
    Re: sine wave v. modified sine wave

    Take a look at some of the hits from this Google search:

    In sum, it seems that many microwave ovens will operate from an MSW inverter. However, there appears to be at least four concerns:

    1) Lower operating efficiency
    2) An inverter power rating should be at least 2X the microwave oven's power spec
    3) A large and healthy battery bank is required to handle the startup surge and the running load
    4) The oven's clock may not work correctly; what will that do to the oven's timer operation?

    Good Luck!
    Jim / crewzer
  • System2System2 Posts: 6,290 admin
    Re: sine wave v. modified sine wave

    Modified sinewaves and clocks, oh boy.

    I ran a 1kw X-brand msw inverter for some parasite loads for 2 years or so. They included a vcr, dvd recorder and telephon answering machine. None of the clocks kept time well and had to be adjusted every few weeks. The less sophisticated the electronics (answering machine) the worse the performance.

    Now everythning is running off the X-brand 4048 and the clocks all keep proper time. I found i was only saving about 50 watts per day by having the smaller inverter for the parasite loads. it's still there, just pulled the in-line fuse to disable until I need a lamp when I'm removing the X-brand and installing the OUtback inverter (i see the future!).

  • rplarryrplarry Solar Expert Posts: 203 ✭✭✭✭✭
    Re: sine wave v. modified sine wave

    I used a MSW inverter and a microwave oven for a year or two and found that the microwave required more time than normal to heat up anything and the clock was pretty much useless. Now for the last 2 years we have been using an Outback 2812 and the microwave works just as it did when we were on the grid.
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