Using a modified sine wave inverter on a Frigidaire?

[tporter]

I'm looking into putting a new refrigerator in my motorhome. My inverter output is a modified sine wave. Are any of you using a modified sine wave inverter / charger with a Frigidaire refrigerator? Any problems? The model i'm looking at is LFHT1817.

Thank you

[Marv_Hoag]

I was looking hard at a Fisher & Paykel 17cu ft French Door refrigerator. The measurements were right for a 1200 LRIM swap. Called the manufacturer today. I was informed they would not guarantee the unit if it was used with a MSW inverter, they would guarantee if used with a PSW inverter. Bummer, I have a 2000w MSW inverter. Back to the drawing board.

I'm going to add that the F&P frig has a lot of electronics, so it didn't surprise me that they wanted the PSW.

I'm going to get out my ruler and shoe horn and have another look at the Samsung RF 197. First I'm going to verify for myself that Samsung indeed approves of the MSW inverter.

[topflite51]

bluebirdPT36 wrote:
Harold1946,
Why don't you buy a quality VOM, infrared therometer, a MSW and a PSW inverter and run the test? Prove that a MSW inverter is just as good and efficient(or better and more efficient) as a PSW inverter. Report back to us when you are finished with the test.

Why should Harold run the test, he has nothing to prove. All those claiming that PSW is better than MSW, should do the funding for an independent lab to do the testing. Or is it just an old wives tale that PSW is better than MSW? I personally would like to know before I spent my MAD MONEY. 😛

[harold1946]

bluebirdPT36 wrote:
Harold1946,
Why don't you buy a quality VOM, infrared therometer, a MSW and a PSW inverter and run the test? Prove that a MSW inverter is just as good and efficient(or better and more efficient) as a PSW inverter. Report back to us when you are finished with the test.

Not interested in doing so. My MSW inverter and refer are doing fine.
Thats why I asked whom was doing the testing. There are many inverter manufacturers as well as refrigerator manufacturers and I wondered where all this data was available at for the hundreds of test results.

[bluebirdPT36]

Harold1946,
Why don't you buy a quality VOM, infrared therometer, a MSW and a PSW inverter and run the test? Prove that a MSW inverter is just as good and efficient(or better and more efficient) as a PSW inverter. Report back to us when you are finished with the test.

[harold1946]

Rich D. wrote:

2oldman wrote:
If MSW works for you, great. A good PSW is much less risk. Not zero, less. I think it's only fair to people reading this that they're aware of that.

X2, exactly!

Harold1946, don't expect others to do your research for you. I find much testing and documentation on sites that support "off the grid" living. I'm sure you can find them too if you really want to. There is only one type of PURE sine wave inverter which almost exactly duplicates 120 VAC household power and then there are many types Modified square wave inverters. The better the MSW, the more steps it makes to approximate a pure sine wave thereby the fewer chances of over-heating, higher power consumption and reduced motor life. MSW inverters are NOT created equally.

And, of course (like the TV commercial with the young lady and the "French Model" date) just because it is on the internet does not make it true. 14 years is a long time in the world of electronics. If your setup worked for you all this time, great. It does not mean a new energy efficient refrigerator won't be harmed by a bad MSW inverter while costing more battery consumption at the same time.

I did not expect anyone to do research, just reference your statement of lab research that has been done. Guess you must have none, thanks anyway.

[Rich_D_]

2oldman wrote:
If MSW works for you, great. A good PSW is much less risk. Not zero, less. I think it's only fair to people reading this that they're aware of that.

X2, exactly!

Harold1946, don't expect others to do your research for you. I find much testing and documentation on sites that support "off the grid" living. I'm sure you can find them too if you really want to. There is only one type of PURE sine wave inverter which almost exactly duplicates 120 VAC household power and then there are many types Modified square wave inverters. The better the MSW, the more steps it makes to approximate a pure sine wave thereby the fewer chances of over-heating, higher power consumption and reduced motor life. MSW inverters are NOT created equally.

And, of course (like the TV commercial with the young lady and the "French Model" date) just because it is on the internet does not make it true. 14 years is a long time in the world of electronics. If your setup worked for you all this time, great. It does not mean a new energy efficient refrigerator won't be harmed by a bad MSW inverter while costing more battery consumption at the same time.

[harold1946]

2oldman wrote:
If MSW works for you, great. A good PSW is much less risk. Not zero, less. I think it's only fair to people reading this that they're aware of that.

In all fairness I would have to agree with that.
When I installed my first residential some 14 years ago, I contacted several manufacturers requesting advise, and all stated they had never done any testing with any type of inverters and were not aware of any being done.
That was the reason I asked about testing lab reports. One can find articles supporting or denying anything the want on the internet.
I have an air guitar I will sell for $100. complete with a certificate of authenticity and a lifetime gurantee. Any takers?

[2oldman]

If MSW works for you, great. A good PSW is much less risk. Not zero, less. I think it's only fair to people reading this that they're aware of that.

[harold1946]

I thought you said you had information from testing labs.

[Rich_D_]

harold1946 wrote:

Rich D. wrote:

harold1946 wrote:

2oldman wrote:

ScottG wrote:
It's going to be better if you have a PSW inverter though and some are getting pretty cheap these days.

Seems strange economics to save a few bucks on an inverter and put who-knows-what at risk. But that's just me.

There is no proof that MSW does any harm to a compressor motor, only those that say it could, may, possibly, or some other form of conjecture.
This is our 14th year with a residential using MSW, and the second MH with the same set up. Previous coach was sold four years ago and the new owners are still using the same 14 year old Amana.
Seems to me it would be poor economics to purchase an inverter when one already exists.

It is not conjecture but fact that MSW inverters cause motors to draw more current, start harder, and have a shortened lifespan. There is much research on line posted by testing labs for "off the grid" equipment.

Remember that all MSW inverters are not created equally. Some have more "steps" to smooth out the square wave than others and those will not be as bad as the ones with fewer steps.

I would like to read some of the test results you refer to, but have not been able to locate any. Everything I find says refrigerator compressors suffer little or no adverse affects from MSW inverters.

Here is just one of thousands.

"The modified sine wave has detrimental effects on
many electrical loads. It reduces the energy efficiency
of motors and transformers by 10 to 20 percent. The
wasted energy causes abnormal heat which reduces
the reliability and longevity of motors and transformers
and other devices, including some appliances and
computers. The choppy waveform confuses some
digital timing devices.
About 5 percent of household appliances simply won’t
work on modified sine wave power at all. A buzz will be
heard from the speakers of nearly every audio device.
An annoying buzz will also be emitted by some
fluorescent lights, ceiling fans, and transformers. Some
microwave ovens buzz or produce less heat. TVs and
computers often show rolling lines on the screen. Surge
protectors may overheat and should not be used."

The full article.

[harold1946]

Rich D. wrote:

harold1946 wrote:

2oldman wrote:

ScottG wrote:
It's going to be better if you have a PSW inverter though and some are getting pretty cheap these days.

Seems strange economics to save a few bucks on an inverter and put who-knows-what at risk. But that's just me.

There is no proof that MSW does any harm to a compressor motor, only those that say it could, may, possibly, or some other form of conjecture.
This is our 14th year with a residential using MSW, and the second MH with the same set up. Previous coach was sold four years ago and the new owners are still using the same 14 year old Amana.
Seems to me it would be poor economics to purchase an inverter when one already exists.

It is not conjecture but fact that MSW inverters cause motors to draw more current, start harder, and have a shortened lifespan. There is much research on line posted by testing labs for "off the grid" equipment.

Remember that all MSW inverters are not created equally. Some have more "steps" to smooth out the square wave than others and those will not be as bad as the ones with fewer steps.

I would like to read some of the test results you refer to, but have not been able to locate any. Everything I find says refrigerator compressors suffer little or no adverse affects from MSW inverters.

[Rich_D_]

harold1946 wrote:

2oldman wrote:

ScottG wrote:
It's going to be better if you have a PSW inverter though and some are getting pretty cheap these days.

Seems strange economics to save a few bucks on an inverter and put who-knows-what at risk. But that's just me.

There is no proof that MSW does any harm to a compressor motor, only those that say it could, may, possibly, or some other form of conjecture.
This is our 14th year with a residential using MSW, and the second MH with the same set up. Previous coach was sold four years ago and the new owners are still using the same 14 year old Amana.
Seems to me it would be poor economics to purchase an inverter when one already exists.

It is not conjecture but fact that MSW inverters cause motors to draw more current, start harder, and have a shortened lifespan. There is much research on line posted by testing labs for "off the grid" equipment.

Remember that all MSW inverters are not created equally. Some have more "steps" to smooth out the square wave than others and those will not be as bad as the ones with fewer steps.

[smlranger]

I put the same fridge in my previous coach, 18 cu.ft. Frigidaire from Lowes. I called Frigidaire (Electrolux) tech support and was told they recommended pure sine wave to ensure longer component life.

Would it have really made a difference? Not sure. However, considering what I paid for the Norcold to residential swap, I decided not to take the risk. I replaced my old MSW inverter with a Magnum Energy PSW unit.

I will say I immediately noticed that the fridge ran quieter when I made the switch.

[harold1946]

2oldman wrote:

ScottG wrote:
It's going to be better if you have a PSW inverter though and some are getting pretty cheap these days.

Seems strange economics to save a few bucks on an inverter and put who-knows-what at risk. But that's just me.

There is no proof that MSW does any harm to a compressor motor, only those that say it could, may, possibly, or some other form of conjecture.
This is our 14th year with a residential using MSW, and the second MH with the same set up. Previous coach was sold four years ago and the new owners are still using the same 14 year old Amana.
Seems to me it would be poor economics to purchase an inverter when one already exists.

[2oldman]

ScottG wrote:
It's going to be better if you have a PSW inverter though and some are getting pretty cheap these days.

Seems strange economics to save a few bucks on an inverter and put who-knows-what at risk. But that's just me.