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Are Inverter Refrigerators immune to what's known as Dirty Power?

Just wondering if having an Inverter refrigerator, for example, means that it is no problem to use a power source with significant THD, (or a modified sine wave) for example?

Does the Inverter in such a refrigerator mitigate any harmful effects of AC power that is not "clean"?
I've never seen the schematic for these and wonder if the Inverter supplies all motors and all electronics on these units or if it only supplies the compressor.

Thanks
 
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kubeek

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What do you imagine actually are the "harmful effects of AC power that is not "clean"?
 

Nigel Goodwin

Super Moderator
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Assuming any 'harmful effects' at all, then I would imagine the (so called) 'digital inverter' system would be far more likely to suffer harm, as it's MUCH more complicated and full of electronics.

I suspect you're been confused by the silly name?, essentially it's just a variable speed compressor and that makes it much complicated (a normal fridge is usually just a plain AC motor, switched ON and OFF by a mechanical thermostat).
 
What do you imagine actually are the "harmful effects of AC power that is not "clean"?
Is it just my "imagination" ?

Are you familiar with Harmonic Distortion? THD?
https://www.aptsources.com/wp-content/uploads/pdfs/Total-Harmonic-Distortion-and-Effects-in-Electrical-Power-Systems.pdf

Certainly it depends on the degree of distrotion. My understanding is that it is generally accepted that "Clean Power" is sinusoidal with less than 6% THD.

Harmonic distortion can lead to increased current in a circuit, generating heat. Heat is not the friend of sensitive electronics.
AC motors are especially prone to problems when harmonic distortion is introduced.
Am I incorrect?
 
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Assuming any 'harmful effects' at all, then I would imagine the (so called) 'digital inverter' system would be far more likely to suffer harm, as it's MUCH more complicated and full of electronics.

I suspect you're been confused by the silly name?, essentially it's just a variable speed compressor and that makes it much complicated (a normal fridge is usually just a plain AC motor, switched ON and OFF by a mechanical thermostat).
Perhaps.
So are you stating that you know for a fact that these Inverter Refrigerators do not actually contain an Inverter or is this a "best guess"?
 

shortbus=

Well-Known Member
Perhaps.
So are you stating that you know for a fact that these Inverter Refrigerators do not actually contain an Inverter or is this a "best guess"?
All it takes is a Quick Google;



Inverter is one of those terms that is loosing it's meaning, like "servo motor". I installed a new furnace in the house a few years ago, it has an inverter motor for the blower, adjusts the speed with the frequency of the call for heat. Runs at a slow speed when there is a long time between heat cycles and then runs faster when it cycles more often.
 

unclejed613

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i wouldn't get too worried about it unless you live next to an industrial park. i noticed the nice informative pdf was rather hazy on what type of equipment was most sensitive to power line distortion. it's also an advertising brochure for their power conditioners, so take it with a grain of salt. where the distortion matters most is in electrical substation equipment and industrial power distribution. (in a factory for instance). most consumer goods really don't seem to be sensitive to it.
 

shortbus=

Well-Known Member
i wouldn't get too worried about it unless you live next to an industrial park. i noticed the nice informative pdf was rather hazy on what type of equipment was most sensitive to power line distortion. it's also an advertising brochure for their power conditioners, so take it with a grain of salt. where the distortion matters most is in electrical substation equipment and industrial power distribution. (in a factory for instance). most consumer goods really don't seem to be sensitive to it.
If I remember correctly the TS is talking about using a mains fridge in a camper with inverter powering it. Think he's the guy that was here before asking about it.
 

debe

Active Member
Here in Australia there is a few that have fitted domestic inverter fridges to there caravans & run them of 12v-240v ac pure sinewave inverters with no ill effects. These campers are ones that are only using battery/solar as there main power source.
 

Reloadron

Well-Known Member
Most Helpful Member
If I remember correctly the TS is talking about using a mains fridge in a camper with inverter powering it. Think he's the guy that was here before asking about it.
Yep, he was inquiring about generator power quality to include inverter type generators. My best thinking here is try to get some data from the guys making the refrigerator and some good data on the power quality of the power source you have. My only other best guess would be in the case of making appliances for RV / Camper type vehicles is the appliances would be designed to run well on the type of available power these things have. Beats the heck out of me? :)

Ron
 
I was referring to regular Home refrigerators. There are standard compressor refrigerators and Inverter Compressor refrigerators.

After Googling it for 15 minutes or so I found the Samsung link I posted.
I saw both of the links SB posted. Neither really explains the inverter from a schematics POV.
Just a very basic summary.
What would really help would be to see a schematic.

Someone on another forum suggested that an inverter refrigerator negated the need for an Inverter generator.
I'm not so sure about that.
I have most definitely had appliance failures (and battery backup device failures) while attempting to run them on a non inverter generator.
It is the one I posted the Waveform in another thread on this forum. I didn't think the waveform from it was horrible, just noisy.

It's always possible my particular generator is particularly bad at generating power....or maybe power surges were the culprit and not so much "dirty power"

I specifically had several fan motors in the freezer fail, a Bosch dishwasher fail and an APC battery backup.

Also, our Frigidaire refrigerator would not get cold when running on the non inverter generator even though it would power up and run.

So from my own experience I have seen what "Dirty Power" can do. I just don't know why and it's being discussed at other forums.
Figured some of you guys might know more about Inverter Refrigerators.

But no, this thread has nothing to do with camper refrigerators, although that might be a related topic so discuss away.
 
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Reloadron

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Someone on another forum suggested that an inverter refrigerator negated the need for an Inverter generator.
You got me on that one. Less knowing the context the statement was made in I see no connection between an inverter type refrigerator which is merely a type of appliance which uses power and an inverter type generator which merely makes power in their simplest terms.

Without actually seeing the generator output which caused the failure of the appliances you mentioned there is no easy way to say why these appliances failed. About all I ever looked at on my generators was the voltage out since nothing ever failed giving me any reason to look further. Low output voltage can be bad for many motors be they fan or compressor motors. I ran a 17 cubic food refrigerator / freezer in italy for 3 years. The compressor did fine on the 50 verse 60 Hz and I used a large 220 to 120 transformer. Initially I worried about the mains frequency and horrible Italy voltage changes but it did fine.My longest generator run time was about an entire week following a severe storm and that was on my older 13 KW natural gas fired whole house unit. All the UPS units ran fine on the generator. Oh as a footnote, I did have one old 1.5 KW APC UPS which did not run well on the generator. Newer good UPS units have settings which allow for generator power, slight voltage or frequency changes don't freak them out. Anyway, no appliances suffered any problems running on the generator which is just an old rotating field design. The same is true of my little old 4.0 KW unit.

I guess I really have no idea where we draw a line between "dirty" and or "clean" power. How dirty or how poor of a quality does power need to be before appliances get suicidal or just start dying I guess is what it comes down to?

Ron
 

debe

Active Member
This is a LG variable speed linear compressor inverter driven. The compressor is basicly a Solenoid driven piston. The powersupply is a switch mode power supply. The fridge will run comfortably of a 300Watt 12V-250Vac inverter as it only draws 15W to 50W during cycles & 150W on defrost cycle. I would be hesitant to run it of a modified square wave powersupply. These fridges dont use mutch power. Other inverter fridges use a variable speed rotary type compressor.F14 .circ diag.JPGPCB.2.JPGPCB.6.JPGF3.JPGF4. spec.JPG
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Perhaps.
So are you stating that you know for a fact that these Inverter Refrigerators do not actually contain an Inverter or is this a "best guess"?
'Best guess' as Samsung's own literature doesn't make any suggestion that it's an 'inverter' as you seem to understand it (and what would be the point?) - it's simply a variable speed compressor - presumably it's PWM, and converts the mains to DC, then 'chops' it to make high frequency AC to vary the speed of the motor.

As I mentioned previously, such a device is MUCH more likely to be damaged by a poor supply than a conventional compressor (which has no electronics to damage).

As no one else seems to have your problems, have you considered that the issue might be with your generator?.
 
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shortbus=

Well-Known Member
I saw both of the links SB posted. Neither really explains the inverter from a schematics POV.
Just a very basic summary.
What would really help would be to see a schematic.
This is what I was saying about the term "inverter" earlier. It has become a "buzz" word. In the refridgerator and my furnace it just means it is an electronically controlled motor in it. A glorified BLDC motor, not induction and not DC. The inverter acts like a variable frequency drive, and a controller is used to pick the speed it will run at in a certain cycle.

Don't understand how seeing a schematic of one will help, because every manufacturer will be different.
 
'Best guess' as Samsung's own literature doesn't make any suggestion that it's an 'inverter' as you seem to understand it (and what would be the point?) - it's simply a variable speed compressor - presumably it's PWM, and converts the mains to DC, then 'chops' it to make high frequency AC to vary the speed of the motor.

As I mentioned previously, such a device is MUCH more likely to be damaged by a poor supply than a conventional compressor (which has no electronics to damage).

As no one else seems to have your problems, have you considered that the issue might be with your generator?.
Interesting. That makes me wonder how the Inverter boards in AC Inverter Generators last so long?

Right. The term "Inverter" in refrigerator seems to be a different term than that associated with generators ie "Inverter Generator"?
Or maybe not? The Inverter is nothing more than a circuit designed to take AC, convert it to DC, then back to AC?

As far as it being just my generator.....it's possible I suppose.

I have posted the waveform from the generator in question in elsewhere....here it is.....
Coleman PowerMate 5000watt open frame generator (6250watt peak). Purchased in 2005.


Maybe someone with a better understanding of harmonics can tell us if this is a potentially harmful Sinusoidal wave form.
It has "some" noise apparently, but overall not a terribly bad waveform. I didn't see any major spiking of voltage.
 
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You got me on that one. Less knowing the context the statement was made in I see no connection between an inverter type refrigerator which is merely a type of appliance which uses power and an inverter type generator which merely makes power in their simplest terms.

Without actually seeing the generator output which caused the failure of the appliances you mentioned there is no easy way to say why these appliances failed. About all I ever looked at on my generators was the voltage out since nothing ever failed giving me any reason to look further. Low output voltage can be bad for many motors be they fan or compressor motors. I ran a 17 cubic food refrigerator / freezer in italy for 3 years. The compressor did fine on the 50 verse 60 Hz and I used a large 220 to 120 transformer. Initially I worried about the mains frequency and horrible Italy voltage changes but it did fine.My longest generator run time was about an entire week following a severe storm and that was on my older 13 KW natural gas fired whole house unit. All the UPS units ran fine on the generator. Oh as a footnote, I did have one old 1.5 KW APC UPS which did not run well on the generator. Newer good UPS units have settings which allow for generator power, slight voltage or frequency changes don't freak them out. Anyway, no appliances suffered any problems running on the generator which is just an old rotating field design. The same is true of my little old 4.0 KW unit.

I guess I really have no idea where we draw a line between "dirty" and or "clean" power. How dirty or how poor of a quality does power need to be before appliances get suicidal or just start dying I guess is what it comes down to?

Ron
I believe Inverter Generator Manufacturers all strive for 6% THD or less. Anything above that (from my research), begins to get into the "Dirty Power" range.
That said, it takes special equipment (I think some newer digital oscilloscopes can) to determine THD.

It seems I sometimes wade into gray areas with electronics. Not intentionally, but because they are "gray" and I like to explore the unknown especially when I have (or think I have) some stake in the game.

It would be interesting to see the waveform from other non inverter generators. Because of all the variables involved, this may be a gray area that will remain gray.
 

crutschow

Well-Known Member
Most Helpful Member
I have posted the waveform from the generator in question in elsewhere....here it is.....
How did you connect the oscilloscope to measure that waveform?
 

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