Wiring refrigerator/ best small one for low kWH

Ok so I think I found the refrigerator I want to buy, Magic Chef 4.0 cu. ft. two door, 290 kWH per year, only thing is it says in the book not to run of a inverter. Whats that about? I will be runing off a 750 W, 1500 W peak, it will be far more then it will use on "start up". Do they just say that in there book to keep people from trying to run it off a 100 W inverter and messing up the motor or something? Or its there a real reason the tell you not to use a inverter?

Other thing is does anyone know of any good 4.0 - 4.4 refrigerator that get better then 290 kWH per year (I don't want to convert a frezzer).

Comments

  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Wiring refrigerator/ best small one for low kWH

    The usual reason for that warning is that modified sine wave inverters can mess up the electronics.
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Re: Wiring refrigerator/ best small one for low kWH

    Have you looked at the energy star site?

    Search for Fridge/Freezer on this page.

    Or go to this page to download the whole list (excel, cvs, html)

    I downloaded the excel file and I could sort based on any set of columns--And I even added a kWhr/cuft column so I could sort on absolute efficiency... Very interesting.

    Playing with the Excel file--I found that 4-5 cuft fridge/freezer typically use around:
    • 60-75 kWhrs per year / cuft
    But you can find 19-30 cuft models that use:
    • 18-23 kWhrs per year / cuft
    The Magic Chef:
    • 290 kWhrs per year / 4 cuft = 72.5 kWhrs per year / cuft
    If you sort just on 290 kWhrs per year or less, and 4-5 cuft, you get:
    Brand Model Configuration Defrost Type Compact Ice Volume Adjusted Volume kWh/year kWh/cuft Federal Standard (kWh/year) Percent Better Active Active Date

    Sub-Zero, Inc. 700BR* Refrigerator Only - Single Door Automatic Yes No 5.27 5.27 204 39 422 52% Yes 2/21/2003

    Haier ESR042PBB Refrigrator/Freezer - Single Door Manual Yes No 4.1 4.10 270 66 343 21% Yes 7/13/2007

    Haier ESR042PWW Refrigerator Only - Single Door Manual Yes No 4.1 4.10 270 66 343 21% Yes 7/13/2007

    Summit CM420ES Refrigrator/Freezer - Single Door Manual Yes No 4.1 4.37 270 66 346 22% Yes 7/17/2009

    Black & Decker BCE46* Refrigrator/Freezer - Single Door Manual Yes No 4.5 4.72 274 61 350 22% Yes 3/16/2009

    GE WMR04GAZ+ Refrigrator/Freezer - Single Door Manual Yes No 4.5 4.50 274 61 347 21% Yes 1/15/2010

    Sub-Zero, Inc. 249RP* Refrigerator Only - Single Door Automatic Yes No 4.9 4.90 278 57 417 33% Yes 2/21/2003

    Haier ESRN046BB Refrigerator Only - Single Door Manual Yes No 4.6 4.60 274 60 348 21% Yes 7/7/2008

    Notice that the 5.27 cuft SubZero stands out as way more efficient than any of the others in that range.

    If you can swing a few more kWhr per year--and need more refrigerator space--then look at the larger models.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • PhotowhitPhotowhit Solar Expert Posts: 5,653 ✭✭✭✭✭
    Re: Wiring refrigerator/ best small one for low kWH

    I had a similar designed "Franklin Chef" that worked fine for 2 years on a semi sine wave inverter (odd hybrid inverter with a MSW at idle and many more steps with a draw with close to a true sine wave, Home power described this a few months back)

    The bad news; The Chiller went out on it cost $100 to repair and the compressor went out with in a month after the repair. This was also the time I had switched to a true pure sine wave inverter. So the compressor died on the true sine wave inverter.

    The good news is it ran on @ a KWh during the summer days and tiny amounts during the fall and spring in unheated area. I turned it off in the winter as I have a freezer at work and don't need a fridge in Missouri.

    Likely, as Windsun said, the warning is based on the MSW creating problems with electrical motors, it might have been a contributing factor though the hybrid inverter ran an AC with out a problem. (the AC continues to work fine for me) Most true sine wave inverters provide very clean output.
    Home system 4000 watt (Evergreen) array standing, with 2 Midnite Classic Lites,  Midnite E-panel, Magnum MS4024, Prosine 1800(now backup) and Exeltech 1100(former backup...lol), 660 ah 24v Forklift battery(now 10 years old). Off grid for 20 years (if I include 8 months on a bicycle).
    - Assorted other systems, pieces and to many panels in the closet to not do more projects.
  • YostFMXYostFMX Solar Expert Posts: 94 ✭✭✭
    Re: Wiring refrigerator/ best small one for low kWH

    So how do you run refrigerator? I've got a harbor frieght MSW 750 W (Please no harbor frieght bashing). So are labtops ok to run on them? Can I just use a old inverter thats not MSW? I need a cheap fix and I'm not going to buy a $2,000 inverter since all I'll have is around 150 watts running at once...
  • YostFMXYostFMX Solar Expert Posts: 94 ✭✭✭
    Re: Wiring refrigerator/ best small one for low kWH

    How is the Xantrex Prowatt SW 600 Watt True Sinewave Inverter? Its that a good cheap one to get? Its like $140.
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Re: Wiring refrigerator/ best small one for low kWH

    Depending on your fridge, 750 watts may be a bit small.

    There is nothing, that I am aware of, that you can do to improve the operation of a piece of equipment on a MSW inverter... Some 80-90% may run fine, another 10% or so may overheat and/or have an early life failure. If the fridge starts OK and the compressor does not feel unusually hot (after running for awhile)--probably all will be OK.

    Typically, for laptop power supplies and other small electronics, if the power supply is Power Factor Corrected (PFC)--they should tend to run fine on MSW inverters. Those that are not--tend to overheat.

    My 10 year old laptop has a non-PFC supply. My new full sized HP laptops have PFC supplies. My brand new HP netbook (20 watts or less) is non-PFC (law typically forces larger supplies/devices to have PFC).

    If you have a Kill-a-Watt meter or equivalent... You can measure the PF... If it is >0.90 or so--should be fine. If <0.70 --- you may have problems.

    All About Inverters
    Choosing an inverter for water pumping

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • solarvicsolarvic Solar Expert Posts: 1,060 ✭✭✭✭
    Re: Wiring refrigerator/ best small one for low kWH

    None of my business but I was wondering why you want such a small refrigerator? I had to replace my fridge because of a lightning strike. Looked around ant tryed to get an energystar fridge a couple years ago. got a 21.6 cubic with an icemaker and cold water. It is rated at 457 kw per year with operating cost $37 It uses less than 100 watts when running. It is a sears. Sears are made by whirlpool. I previously had a GE fridge with the computer control board. The repairman told me to try and get one without the computer boards and whirlpool was one of the few manufactures that still made some of the models without them. That might have been one of the reasons they said not to use an inverter. I agree that you should have a sinewave inverter if you plan on running a fridge. Vic FORGOT TO SAY! THERE IS SUPOSED TO BE A CASH FOR CLUNKERS SALE. It is part of the stimioulous package to get people to upgrade to energystar appliances
  • mikeomikeo Solar Expert Posts: 386 ✭✭✭
    Re: Wiring refrigerator/ best small one for low kWH
    Have you looked at the energy star site?
    Yes for less then 60kwh more a year you can get a 19 cf model if you could use the extra room for less then $700.
    http://www.ajmadison.com/ajmadison/itemdocs/W9RXXMFWQ_Energy_Guide.pdf

    These are available from the big box stores on special order also when I checked.
  • YostFMXYostFMX Solar Expert Posts: 94 ✭✭✭
    Re: Wiring refrigerator/ best small one for low kWH

    A small frig is all I need really (only one guy) and thats all that I the bigger I can run on 615 watt (along with eveything else).

    I think 600 watt 1200 watt max inverter should run a 290 kWh per year refrig no problem, right? I think it was something like 100 watts or 120 when its running, and with start up it would have to use more then 9 X the power to not work on that size inverter. It sounds right to me anyway, but what do I now? I'm new at all this...

    So is a "Xantrex 600 Watt True Sinewave" a good one to get?
  • BB.BB. Super Moderators, Administrators Posts: 32,007 admin
    Re: Wiring refrigerator/ best small one for low kWH

    The motor starting current is one issue--if Self Defrost, then the de-icing heaters (another 500 watts or so) are another (heaters are probably much smaller, or non-existent, manual defrost/in the small cuft sizes--only one model I listed was auto defrost).

    By the way--is there a reason you did not want to do the "chest freezer as a refrigerator" conversion? These conversions can give you a cheap, 7+ cuft refrigerator that runs on ~0.25 kWhrs per day or less than 100 kWhrs per year.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
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