Inverter Refrigerator questions

ILFE
ILFE Solar Expert Posts: 364 ✭✭
Some fairly recent talk got me thinking about looking for a new inverter refrigerator. I had looked around town before. No luck. Tonight, it seems I hit the jackpot. I have found one - several in fact. Anyway, here are the specifications on one unit I found. (Others were all Samsungs that I have yet to explore):

Attachment not found.

Make: LG
Model: GN-B222 SLCL

Gross Capacity: 225 liters / ~8.0 ft3

Power: 220vac - 50hz / 1.2 amps / 130w
Rated Input of Heater Cord: 95 watts (I'm not sure what this is?)

Price: $385 USD

I have zero knowledge of inverter refrigerators. I was wondering you fellows could tell me if it may be possible to run this unit from a 300 watts inverter. If not, what would be the minimum inverter I could run it on, by itself? I am under the impression inverter refrigerators can run on much smaller inverters due to efficiencies?
Paul

Comments

  • BB.
    BB. Super Moderators, Administrators Posts: 33,431 admin
    Re: Inverter Refrigerator questions

    In general, an inverter refrigerator is along the lines of:

    AC power in => Variable Frequency Drive (aka "inverter") => (typically) 3 phase induction or PM motor driving compressor

    A permanent magnet motor may cut power usage by something like 20% (induction motor generates a magnetic field in the armature between the rotating field generated by the AC power and the rotor. This "slip" generates a current in the rotor which is what the outer rotating field drags around... I.e., at 60 Hz, 1,800 RPM rotating field, 1,735 RPM or so rotating shaft, ~75 RPM "slip" to generate rotor field).

    So, you have an "inverter" (VFD) that can soft start, soft stop, and variable speed (no on/off but variable amount of cooling based on needs at the moment).

    What does a specific manufacturer do in a particular appliances--"It depends".

    Some links (PR and otherwise):

    http://refrigerators.reviewed.com/features/digital-inverter-compressors-can-t-we-all-just-chill-out
    https://www.bijlibachao.com/refrigerators/refrigerators-with-inverter-technology-can-help-save-electricity.html
    [h=3]Lesser known benefits of Inverter Technology[/h]
    • Regular motors need 3-4 times more current (more than running current) at startup. So the inverter/generator size needed to run any AC or Refrigerator increases significantly. But Inverter Technology air conditioners and refrigerators have variable speed motors that start up gradually needing much lesser current at startup. Thus the size of inverter/generator required to startup is less. For e.g. A 1.5 ton fixed speed AC that runs at about 10 Amp current may need up to 30 Amp current at startup and thus a 5 kVA inverter/generator. But an inverter technology Air Conditioner needs about 6-7 Amp current and not much more at startup and thus a 1.5 kVA or 2 kVA inverter/generator is good enough to support it.
    • Regular motors have much lower power factor. In commercial and industrial connections there is penalty for low power factor and rebates for higher power factor. An inverter technology motor will have power factor close to unity (or 1) which not only results in lesser electricity consumption but also help get rebates on better power factor.
    • If you are planning to use Solar PV for air conditioner, then it is the best to use inverter technology air conditioner or refrigerator as it not only reduces the size of PV panels because it consumes lesser electricity, it also reduces the size of inverter to be put along with the PV panel.
    https://www.samsung.com/latin_en/consumer/home-appliances/refrigerators/top-freezer/RT38FEAKDSL/AP
    Unlike conventional compressors, which have just two patterns of start and stop, Samsung’s Digital Inverter Compressor makes 5 different moving cycle based on humidity levels and usage patterns. This helps maintain a more consistent temperature, reduces wear and tear on the compressor for greater durability, and keeps noise to a minimum. You’ll also enjoy the peace of mind that comes with lower electric bills and a 10-year warranty.

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • oil pan 4
    oil pan 4 Solar Expert Posts: 767 ✭✭✭✭
    Re: Inverter Refrigerator questions

    If they are 3 phase motored and ran on freq drives then you can soft start them and eliminate nearly all inrush current.
    I am working with frequency drives more. They are pretty cool.
    Main down side is the initial cost. 3 phase VFD rated motors and the drivers aren't cheap.

    Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

    Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

  • petertearai
    petertearai Solar Expert Posts: 471 ✭✭✭✭
    Re: Inverter Refrigerator questions

    Hi I purchased a samsung inveter fridge freezer about a year ago . Runs nicely on my 1800 watt inverter . uses less power than on star rating and is Quieter than my old non inverter Samsung . All good so far.
    2225 wattts pv . Outback 2kw  fxr pure sine inverter . fm80 charge controller . Mate 3. victron battery monitor . 24 volts  in 2 volt Shoto lead carbon extreme batterys. off grid  holiday home 
  • ILFE
    ILFE Solar Expert Posts: 364 ✭✭
    Re: Inverter Refrigerator questions

    Thanks, Bill.

    I finally got my g/f to send me the image she took last night. (Attached below)

    oil pan 4 wrote: »
    If they are 3 phase motored and ran on freq drives then you can soft start them and eliminate nearly all inrush current.
    I am working with frequency drives more. They are pretty cool.
    Main down side is the initial cost. 3 phase VFD rated motors and the drivers aren't cheap.

    This one, comparatively speaking, is not much more than conventional refrigerators, locally. At $385 USD, I would be willing to pay that much for one. I have not priced the Samsung models. I figure they may even be a bit cheaper.

    Hi I purchased a samsung inveter fridge freezer about a year ago . Runs nicely on my 1800 watt inverter . uses less power than on star rating and is Quieter than my old non inverter Samsung . All good so far.

    Well, that's the thing. If I am going to buy one of these new fangled gadgets, paying a bit more for it than a standard refrigerator, I want it to be able to run on as low of wattage inverter as possible. 300 to 350 watts would be PERFECT, if it would run on that. To be honest, I could run my current (older, much smaller power hog) refrigerator on an 1,800 watts inverter. My current refrigerator uses 2.8 kWh every 24 hours, by the way. At 1,500r (.375c US) / kWh, I want to gain savings, if possible. (That unit runs in our home, off mains power.)

    Not to mention, I would like to run the inverter refrigerator at our farm, where no mains power currently is. It would be totally dependant upon solar, and no other power source.
    Paul
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Inverter Refrigerator questions

    thought that it was a bit on the lower cost side then I noticed it is only 8 Cu. ft. as opposed to a more normal size fridge of 15 + cu. ft. Darn.

    Mind you the normal size for NA uses in the low 300 -350 W running now with about 1 Kwh per day and in the $800+ Dollar Cdn depending on features...
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • ILFE
    ILFE Solar Expert Posts: 364 ✭✭
    Re: Inverter Refrigerator questions
    westbranch wrote: »
    thought that it was a bit on the lower cost side then I noticed it is only 8 Cu. ft. as opposed to a more normal size fridge of 15 + cu. ft. Darn.

    Mind you the normal size for NA uses in the low 300 -350 W running now with about 1 Kw per day and in the $800+ Dollar Cdn depending on features...

    Not sure if they will let me run it prior to buying it. Usually, that is only allowed AFTER you have agreed to make a purchase. I can probably use my power meter, though, to at least see what it draws on startup and running.

    They have much larger units here. But, I am trying to get one that will use as little power as possible. Heck, I recall us having a large side by side in the house, and outside in the garage, another ref and two chest type deep freezers. (I come from a large family.)
    Paul
  • oil pan 4
    oil pan 4 Solar Expert Posts: 767 ✭✭✭✭
    Re: Inverter Refrigerator questions

    You could always convert a deep freeze to a fridge.
    They use hardly any power. I have been hearing number like .250 to .350 hwh per day.

    Solar hybrid gasoline generator, 7kw gas, 180 watts of solar, Morningstar 15 amp MPPT, group 31 AGM, 900 watt kisae inverter.

    Solar roof top GMC suburban, a normal 3/4 ton suburban with 180 watts of panels on the roof and 10 amp genasun MPPT, 2000w samlex pure sine wave inverter, 12v gast and ARB air compressors.

  • ILFE
    ILFE Solar Expert Posts: 364 ✭✭
    Re: Inverter Refrigerator questions

    Our landlord (here in Cambodia) recently purchased a new Samsung Inverter Refrigerator. Not sure of the model number, but i would guess about 10 cubic feet or so?

    I plugged my power meter into it 2 days and 2 hours ago. This refrigerator is in a home with two adults and two children. Over that time, here are the readings:

    Total kWhs used: 1.864
    Lowest watts registered: 2.0
    Highest watts registered: 222.5
    Mains: 230vac
    Cycles: 50hz

    So, I am under the impression a 300 watts - 350 watts inverter would run that sized refrigerator fine. The one I am interested in, I hope will even draw a bit less.
    Paul
  • westbranch
    westbranch Solar Expert Posts: 5,183 ✭✭✭✭
    Re: Inverter Refrigerator questions

    Went into the local store selling LG fridges and asked about their inverter type fridges and yearly rating.
    He had a promo video that was quite short and it explained how LG linear compressors work, found it on YouTube...
    http://www.youtube.com/watch?v=sKf_v7URTtg

    Interesting comparison of surge, on a graph , of both types of compressor...
     
    KID #51B  4s 140W to 24V 900Ah C&D AGM
    CL#29032 FW 2126/ 2073/ 2133 175A E-Panel WBjr, 3 x 4s 140W to 24V 900Ah C&D AGM 
    Cotek ST1500W 24V Inverter,OmniCharge 3024,
    2 x Cisco WRT54GL i/c DD-WRT Rtr & Bridge,
    Eu3/2/1000i Gens, 1680W & E-Panel/WBjr to come, CL #647 asleep
    West Chilcotin, BC, Canada
  • john p
    john p Solar Expert Posts: 814 ✭✭✭
    Re: Inverter Refrigerator questions

    I have tested a 10cft Panasonic inverter fridge on a good 400w inverter and it started 99% of the time perfectly on a 600w inverter it started 100%of the time..And ran very quiet.. The inverter never got more than a couple deg c above ambient... They are the way to go for off grid use . lower power use in total than the regular 12/24 v danfos powered fridges.. Converting a freezer to a fridge does NOT decrease the start up current needed.