Forum Discussion

supercub's avatar
supercub
Explorer
Jul 07, 2014

Inverter for Residential Frig ????

First off, I don't know if I have a pure or modified sine wave inverter. Yes, I will find out. However, for now, lets assume I have a modified 2000 watt inverter in my motorhome.
1. If I install a residential frig that needs a pure syn wave, can I install a second invertor that is devoted to just the frig? I ask this, because I'm assuming buying a smaller invertor would be much cheaper then replacing my 2000 watt invertor which runs fine.
2. If you can run a second inverter, can you run it off the same battery bank that runs the 2000 watt existing inverter? I have 4-6 volt batteries.
3. What size invertor would I need to run a residential frig?
Thanks
Brian

17 Replies

  • How bout if I was to use this model, what would be the answers to questions 1,2 and 3 above.
    http://www.homedepot.com/p/Whirlpool-14-4-cu-ft-Top-Freezer-Refrigerator-in-White-W4TXNWFWQ/203487910?MERCH=REC-_-PIPHorizontal1-5-_-NA-_-203487910-_-N#specifications

    Thanks again.
    Brian
  • wa8yxm's avatar
    wa8yxm
    Explorer III
    I have read, here on the forums, that motors need a pure sine wave, I have operated several motors off MSW inverters many times and have thus not been able to confirm that you got have a true sine for motors.

    Electronics, on the other hand, are another issue.... SO...

    Refrigerators come in two types for this chat.. ONE is basic, has a mechanical thermostat and usually a timer motor for the defroster, and other mechanical sensors, Not so much as a single Transistor or Integrated circuit.

    Others are computer controlled. Some of these may need TSW

    Some (And these are the ones I recommend) actually do not run on 120vac at all, they may run on 48 volt or some other voltage but from the user's point of view they are 120/12 volt devices. (They convert as needed internally) These puppies draw around 35-50 watts, That's compares to a standard double lamp light fixture, NOT what you'd call a lot of power. No inverter needed (Built in) they are a bit more expensive, but well worth it. These come in both Upright and "Chest" models. I have a small chest freezer of this type used it in the house and now use it in the motor home.. Very nice, saves $$$ on power bills.
  • Ivylog wrote:
    The compressor in a 197 is DC so it's better for running on a MSW inverter.


    Could you please explain this?

    To answer the OPs question, you can run a small 1000 watt inverter to power a residential refer and a lot of people do. I know for a fact that the Samsung 197 will run on a MSW inverter with no problems.

    The residential refers can go all night without power and in the morning, the ice cream will still be like a rock and the beer still cold.
  • I run a 10cu-ft fridge off a Xantrex X-power modified sine wave converter. It is 1000 watts (2000 watts peak). There is a 6 foot run of 2 gauge wiring to the batteries. I have them hooked to the two Trojan T-125 batteries (10yrs-old) that supply the whole coach. I've had them run all day and all night without a problem. I had my doubts, but it all seems to work just fine.
  • Ivylog's avatar
    Ivylog
    Explorer III
    The compressor in a 197 is DC so it's better for running on a MSW inverter. A 1200 watt inverter should start most refers.
  • Impossible to answer questions without knowing what residential fridge your talking about. Differing sizes and models will require wildly different power resources.
  • Personally, I would not run off an inverter. Only on generator or shore power.
    Suspect would drain the batteries faster than I would want.
    Stick with LP if boon docking a lot.