Forum Discussion

kmb1966's avatar
kmb1966
Explorer
Apr 25, 2020

New inverter, new frig - Magnum ME2012

Recently we had our Norcold 1200 replaced with a new Fisher & Paykel residential refrigerator which is supposed to have an inverter controlled compressor (variable speed). Our Newmar motorhome never had an inverter, so the RV shop installed an inverter and it all seems to work just fine. Everything has power while on the inverter except the water heater and A/C units. The inverter they installed is a Magnum inverter. It is a model ME2012-20B. It is a gray colored cabinet and I think it is a modified sine wave, not a pure sine wave. My question is, SHOULD I BE CONCERNED that they did not put a pure sine wave? I suppose the pure sine wave was slightly more, but they really never asked me about this prior to installing, I just knew they were installing a Magnum inverter.
Should I insist on changing this out and replacing it with the pure sine unit??
  • Lwiddis's avatar
    Lwiddis
    Explorer II
    Apr 25, 2020
    I’ve got too much good electronic stuff to trust using a MSW inverter.
  • 2oldman's avatar
    2oldman
    Explorer II
    Apr 25, 2020
    Lord help me if I ever trust an RV shop to do anything pertaining to electrical work.
  • BFL13's avatar
    BFL13
    Explorer II
    Apr 25, 2020
    No trouble with two different res fridges (120v only) with MSW inverters.

    Have a PSW one now that runs the 1990 RV microwave OEM in this MH, which will not run on MSW. However all the newer (since 2003) MWs we have tried with MSW in our RVs ran ok.

    A friend with a newer fancy sewing machine could not run it on MSW. It needed PSW.

    So it depends if you will be wanting to run anything that does need PSW, but the fridge will be ok.
  • theoldwizard1's avatar
    theoldwizard1
    Explorer II
    Apr 25, 2020
    Yes, that is a modified sine wave inverter. Your microwave won't like it, but if the refrigerator use a variable speed compressor, it won't care. (The 120VAC is converted to variable frequency 3 phase.)

    Modified sine wave inverters a less efficient. For $200-$300 more, you could have gotten a pure sine wave inverter/charger/automatic transfer switch. Get rid of your converter (wire the DC distribution panel directly to the house batteries). The automatic transfer switch means you will have AC as long as you are plugged in or have adequate battery power.

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