Residential Refrigerator / MSW vs PSW Inverter

[Robin_M]

Originally Posted by vsheetz

And as I am a fan of point of use inverters to maximize efficiencies I would suggest to install a separate inverter for the refrigerator.

Good point, Vince. Point of use inverters do maximize efficiency. Another iRV2 member installed one for his RF197, even though he didn't really need to. The reason was that he does a large amount of boondocking, and he wanted to have the flexibility of more efficient power management with his main inverter.

[Robin_M]

Originally Posted by charles tuit

I installed a Haier 10.3 CF. I run it when not plug in on a Xantrex 458 modified sine, 2000 watt inverter/charger that was installed before the change. In approx. 1 year's time I have had zero problems. The only adjustment I have to make is when on inverter it runs slightly colder. I have 2 settings on the thermostat. One for inverter and one when plugged into 110 volts.

Charles,

You don't hear much about Haier Refrigerators in the U.S., but I understand they are a high-end brand in Europe. My understanding is that they are a joint venture between companies in China and Germany. They are also quite innovative. Take a look at this article about the new Digital Inverter Compressor technology that I ran across while researching inverters and compressors on Samsung units. Haier apparently was the first to bring this technology to market.

Maybe your compressor runs slightly faster with the MSW inverter. MSW inverters have a tendency to effect electric motors more than most things. I remember the old example of an electric clock not keeping proper time, but I can't remember whether the clock was supposed to run fast or slow.

[Robin_M]

Originally Posted by PyrateSilly

We had already taken out and replaced our 1500 watt modified inverter with a 3000 watt pure sine inverter about a year before changing the fridges. ...Pretty much everything in the coach runs thru the inverter, that's the way it was built, so just better for us to go the route of a new, larger pure one.

Christine,

That was a good upgrade, and it apparently seems to have paid off well for you. I plan to do the same if and when my 2000w Magnum MSW inverter ever conks out.

[Robin_M]

Originally Posted by Ramets

When I finally threw out my Dometic fridge, I put in a Whirlpool. I already had a Magnum 3000w PSW inverter & 480 watts of solar, along with my AGM's. But the main reason we went with the Whirlpool was the ease of any maint. that might have to be done. By removing the outside panel a tech can easily get to all the working parts of the fridge. Don't have to worry about trying to slide it out to fix anything.

That's a great consideration. When my Samsung was installed I had them leave off the lower back access cover for the same reason. I was looking at it yesterday. I think a technician could get to most everything including the main power board if he worked at it, but it would be a bit tight. On my unit the hole for the outside access is positioned just a bit too high for the Samsung.

[charles tuit]

Originally Posted by Robin_M

Charles,

You don't hear much about Haier Refrigerators in the U.S., but I understand they are a high-end brand in Europe. My understanding is that they are a joint venture between companies in China and Germany. They are also quite innovative. Take a look at this article about the new Digital Inverter Compressor technology that I ran across while researching inverters and compressors on Samsung units. Haier apparently was the first to bring this technology to market.

Maybe your compressor runs slightly faster with the MSW inverter. MSW inverters have a tendency to effect electric motors more than most things. I remember the old example of an electric clock not keeping proper time, but I can't remember whether the clock was supposed to run fast or slow.

I am not electronically skilled however I bought the Haier for $350 delivered and old one hauled away. If it lasts 5 years I am happy. It costs more to trouble shoot and repair the old Norcold than a new Haier. I don't think mine is the new style as my compressor does cycle on and off. If my inverter goes down I will consider a pure sine wave. Thanks for the info.

[Winepress]

I went back to my appliance dealer friend to confirm the compressor used on the RF197. I was very confused on the schematic and the posts on this thread. He laughed at me, "Don't you trust me?" He showed me the compressor model number as MK162D-L1U shown on page 8 of the service manual. This is a standard Samsung 115 ~ 127 VAC 60hz compressor, not variable speed utilizing inverter technology. He showed me the compressor in his service manuals. He then showed me the wiring schematic page 96 showing the inverter compressor as an option labeled "PBA sub inverter option". This "option" is not available in the USA at this time. The higher end Samsung's use the variable speed compressor although he said he has yet to see one in service. They are part of the BLDC series. He pointed out on the diagram below the "PBA option" and said “Look, here is the wiring for the compressor that our units use in the USA.
I have access to the rear of my unit thru the old Norcold vent. My compressor has part # MK162D-L1U. Maybe newer units, or older units have something else.
Like I said earlier, I don't think it makes a bit of difference as the refrigerator runs fine on shore or MSW, however having PSW would not hurt.

[Tony Lee]

Any time you run ANY electronics off a Modified Square (let's call it for what it really is rather than pretending it is something it is not) Wave inverter, you take a chance on premature failure. Granted, anything with a switch-mode type power supply (power bricks) with a voltage range of 100V AC to 250V AC are generally OK, but there are plenty of stories about fans, electric blankets and coffee makers incorporating fancy electronics lasting only a few hours on MSW inverters. In a residential fridge, even having a non-speed controlled compressor unit, there may be all sorts of electronics controlling fans and defrost controls and temperature controls that might have problems with non-Sinewave power supplies.



Then not all M Square W inverters are the same and depending on how they "make" the waveshape, can have quite wide variations between the ratio of Peak Voltage to RMS Voltage and the further the departure from a pure sinewave, the worse this ratio becomes and if the appliance contains any sort of surge suppressor in its power supply, the high peak voltage will force the suppressor into conducting on every cycle peak and it will die very quickly.

If you can't find out whether an appliance is rated for MSW input, then all you can do is buy from a store offering unconditional no questions asked return policy, run the appliance 24/7 for at least a week and if it blows up, take it back for a full refund and try another brand.

[PushedAround]

Originally Posted by Winepress

I went back to my appliance dealer friend to confirm the compressor used on the RF197. I was very confused on the schematic and the posts on this thread. He laughed at me, "Don't you trust me?" He showed me the compressor model number as MK162D-L1U shown on page 8 of the service manual. This is a standard Samsung 115 ~ 127 VAC 60hz compressor, not variable speed utilizing inverter technology.

Well now I feel much better in having spent $800 more for my refrigerator than you did for yours. Of course, mine has water in the door.

[Robin_M]

Originally Posted by Winepress

I went back to my appliance dealer friend to confirm the compressor used on the RF197. I was very confused on the schematic and the posts on this thread. He laughed at me, "Don't you trust me?" ...He then showed me the wiring schematic page 96 showing the inverter compressor as an option labeled "PBA sub inverter option". This "option" is not available in the USA at this time. The higher end Samsung's use the variable speed compressor although he said he has yet to see one in service.

Well, shoot! Winepress, nothing personal, but you remind me of the Streisand song "Don't Rain on My Parade".

Just kidding of course, but you can't blame me for trying. Actually, I see what he is saying. If you follow the neutral side of the power input, you can surmise that the high voltage RY73 relay module probably turns the compressor on/off as needed by connecting the other side of the motor to the common leg of the power input. (As you pointed out, the hot side is directly connected.) It's hard to tell exactly what RY73 does because the diagram there doesn't seem to be complete.

No offense to your friend, but one day soon I may take the cover off that PCB board and see if that compressor inverter module option is there or not. At least now I know what it looks like and where it should be on the board, if it's there at all. By the way, when he said the new units with the variable speed converters are "high-end" units that are not out yet in the U.S., I wonder if he was talking about the new "Digital Inverter Compressor" technology described HERE.

If your technician friend is correct (and I assume that he most likely is), this changes what almost everyone in the iRV2 threads believes about the Samsung RF197. Now I'm beginning to wonder how to know with certainty that these Samsung refers are indeed "certified" for use with a MSW inverter.

[Robin_M]

Originally Posted by PushedAround

Well now I feel much better in having spent $800 more for my refrigerator than you did for yours. Of course, mine has water in the door.

Don't be so smug, Larry. He shot us both down. I was just a bit further out on the limb.

[tricotec]

Originally Posted by Winepress

As far as I can tell in looking at the schematic for the RF197, there is no inverter within the refrigerator. The 120VAC goes straight into the compressor. My appliance dealer friend got me the wiring diagram and said it was nothing special. The compressor is a standard model. Some of the higher end Samsung's do utilize a variable speed compressor, but not the 197. He did say that the unit would be better off on a PSW, so that's another future project if I keep this coach.
That said, the unit appears to run fine on the MSW and the members experience seem to indicate there are no issues.
I also have a small "dorm" style refrigerator in one of my outside bays. It runs fine as well.


Try and live up to your dogs opinion of you.

The RF197 works perfectly on our MSW. It is also approved for such use by Samsung. Many, many people owning mid 2000's RVs with MSW inverters are installing these with absolutely no issues whatsoever...including me. That said, a small PSW inverter can be had for $250 or so. I wouldn't waste your money though...definitely not needed.

[Winepress]

Can someone point me to a URL or document that references that Samsung states that it is approved to run on a square wave inverter?
I'd like to have a copy for my records.......and warranty.

[Robin_M]

I called Samsung US customer support with this question. That didn't work. So I left an email inquiry on their technical support page. We'll see if they answer it.

I agree with you (and tricotec) that this is not much of an issue, but it sure would be nice to hear that from Samsung.

[Pigman1]

We replaced the old Norcold in our 2008 Bus we put in a 21 cu ft KitchenAid. As part of the mod I went to 6 Lifeline AGM batteries and put a Tripp Lite dedicated inverter in to run the refrigerators. Based on my daughter's recommendation (she's a Lowes store manager and she based her recommendation on warranty claims she sees on numerous customer complaints) we chose the KitchenAid. In addition, the Tripp Lite was a MSW inverter. We ran that combination for 3 tears and loved it. Never a problem.

When we got the new 2013 Bus it was equipped with a 17 cu ft KitchenAid and I put another Tripp Lite MSM inverter in as a dedicated power source. This inverter runs the RR at all times and is also set up to run a 17 cu ft chest freezer in the toad and a 3 cu ft freezer in the basement. We boondock extensively and bring frozen fish down from Alaska. We have 31,000 miles on the new bus in 15 months.

It should be noted that the KitchenAid and also Whirlpool RR's do NOT have PC boards or integrated circuits like the Samsungs