Video Suggestion - Super Capacitors used to start a Refrigerator

[E. Bryan Hoover]

This is a suggestion FOR A VIDEO to show using Super Capacitors to start a Refrigerator.

 

[Ampster]

This is a suggestion FOR A VIDEO to show using Super Capacitors to start a Refrigerator.

My refrigerator is an inverter start so I don't need to worry about starting it or it using much energy.
I would like to see a video about the advantages of inverter start refrigerators, Air Conditioners and anything else that has a soft start to be easier on off grid or RV systems.

 

[E. Bryan Hoover]

My refrigerator is an inverter start so I don't need to worry about starting it or it using much energy.
I would like to see a video about the advantages of inverter start refrigerators, Air Conditioners and anything else that has a soft start to be easier on off grid or RV systems.

This raises several questions.

Which refrigerator did you buy that is based on inverter technology (Make and Model)?

What are the alternative refrigerators (make and module) that use invertor technology?

Is it that your invertor refrigerator DOES NOT START or is it that your invertor refrigerator STARTS LESS OFTEN?

How much did you invertor refrigerator cost?

When did you buy your invertor technology refrigerator?

What size is the refrigerator portion of your refrigerator?

What size is the freezer portion of your refrigerator?

I am familiar with HVAC invertor technology - not only was the equipment much more expensive BUT the distribution of air was critical in an invertor HVAC system AND I suspect that also causes issues with refrigerators.

 

[Ampster]

Which refrigerator did you buy that is based on inverter technology (Make and Model)?

GE made by Hajer

What are the alternative refrigerators (make and module) that use invertor technology?
Is it that your invertor refrigerator DOES NOT START or is it that your invertor refrigerator STARTS LESS OFTEN?

I don't know what other brands use inverters.
I never hear it start but maybe is runs so slow that it never stops.

How much did you invertor refrigerator cost?
When did you buy your invertor technology refrigerator?
What size is the refrigerator portion of your refrigerator?
What size is the freezer portion of your refrigerator?

It was on sale a year and a half ago at Home Depot. I think around $1100
I don't know the cubic feet. It fit in the hole in the wall just right.
It was a French door with a roll out bottom freezer. i know the freezer can hold over 75lbs of frozen Salmon I brought back from Alaska last year.

I am familiar with HVAC invertor technology - not only was the equipment much more expensive BUT the distribution of air was critical in an invertor HVAC system AND I suspect that also causes issues with refrigerators.

I don't know other than how the compressor is run how air circulation would be any different with a non inverter refrigerator. Care to enlighten us. The Inverter start AC units i have looked at are split units and I also don't know why that would affect the wall unit which also has a variable speed fan.

 

[gnubie]

Mine's an LG GT-279MWL.

Mine runs the compressor most of the time except in winter when the cooling required is so low that the compressor running at any speed is too much. I've seen it get down to 12Wh / h during those times.

Typical summer (>30c in the kitchen) consumption across a 24h period is 960Wh.

My fridge is free standing against a wall, not enclosed. Any enclosure built for any fridge should be acceptable really. Basic rules apply regardless of design. Ensure cleear air flow around all heat dissipating surfaces.

full product details

 

[RCinFLA]

Most of the larger Samsung's are inverter technology. Inverter refrig and air conds are more expensive so usually only found on larger models. Many of the mini-split air cond units are inverter technology and their startup current is only a slight amount over their run current.

Inverter technology uses a three phase variable speed compressor motor. The inverter converts single phase electric to DC that runs the variable frequency output three phase inverter. The variable frequency allows the compressor motor speed to be continuously varied based on refrigerent flow need. It also allows the soft start to prevent current surge that would overload the single phase AC to DC converter.

The fan motors are usually regular type single phase motors, perhaps with couple of speed settings.

Over average range of use they are more efficient. When run at maximum power they are actually a little less efficient then regular refrig due to losses of inverter.

Similar motor arrangement used on all electric vehicles.

 

[tictag]

The inverter converts single phase electric to DC that runs the variable frequency output three phase inverter. The variable frequency allows the compressor motor speed to be continuously varied based on refrigerent flow need.

Very interesting. I suppose if you tried a simple single-to-three phase conversion you wouldn't have frequency control, hence the rectification to DC, then inversion to three-phase AC. Very cool (and very pun-tastic).

 

[Ampster]

Yes it is the frequency that allows them to startup with very little surge and run at low speed when there is no major temperature demands. Much more efficient except at high usage or when i leave freezer drawer slightly open and the freezer looks like it got hit by blizzard.

 

[RCinFLA]

The fancy piece of converting single phase AC o DC is doing it with a good power factor. Europe has much stricker regulations on power factor then U.S. No more just rectifying to a large filter capacitor like days of old.

There are specific integrated circuits that do most of the fancy work at low cost. Basically, full wave rectify and run into a boost DC to DC converter with a boost inductor charging at high frequency with inductor charge current duty cycle profile that matches 50/60 Hz sinewave half cycle. Other detail is doing this without letting a bunch of EMI (switching noise interference) escape.

Almost all switching power supplies greater then 75 watts these days have the same power factor correction circuitry. European regulation EN61000-3-2 requires all switched-mode power supplies with output power more than 75 watts have a good power factor and low harmonic components of load current. There are rumblings of lowering that power level to cover most LED light bulbs.

 

[E. Bryan Hoover]

GE made by Hajer
I don't know what other brands use inverters.
I never hear it start but maybe is runs so slow that it never stops.

It was on sale a year and a half ago at Home Depot. I think around $1100
I don't know the cubic feet. It fit in the hole in the wall just right.
It was a French door with a roll out bottom freezer. i know the freezer can hold over 75lbs of frozen Salmon I brought back from Alaska last year.

I don't know other than how the compressor is run how air circulation would be any different with a non inverter refrigerator. Care to enlighten us. The Inverter start AC units i have looked at are split units and I also don't know why that would affect the wall unit which also has a variable speed fan.

Very complete reply.

Thank-You

 

[E. Bryan Hoover]

Invertor technology varies the speed at which BOTH the compressor AND the fan that puts a load on the compressor (the fan on the inside of the fridge) - the speed at which both runs must be perfectly matched.

In the case of a HVAC system the duct work must be both designed AND built perfectly so that the balance of air between rooms remains constant REGARDLESS OF THE SPEED. This requires an old school master craftsman (which we had access to - but - why - is beyond the scope of this discussion).

The reason an advantage to an invertor HVAC system existed was that the invertor HVAC system rarely shuts off it just slows way down and matches Speed TO Load.

The problems with HVAC SYSTEMS were three: 1). Three times the cost of equipment, 2. Very poor performance, OR, 3. The high cost of having a Master Craftsman Design and Build the duct work.

 

[gnubie]

I'll remember to only buy an inverter fridge where the manufacturer specifically states their compressor and internal fan speed have been taken into consideration as part of the normal design and testing process.

Oh wait, that'll be all of them.

 

[JoeHam]

Invertor technology varies the speed at which BOTH the compressor AND the fan that puts a load on the compressor (the fan on the inside of the fridge) - the speed at which both runs must be perfectly matched.

In the case of a HVAC system the duct work must be both designed AND built perfectly so that the balance of air between rooms remains constant REGARDLESS OF THE SPEED. This requires an old school master craftsman (which we had access to - but - why - is beyond the scope of this discussion).

The reason an advantage to an invertor HVAC system existed was that the invertor HVAC system rarely shuts off it just slows way down and matches Speed TO Load.

The problems with HVAC SYSTEMS were three: 1). Three times the cost of equipment, 2. Very poor performance, OR, 3. The high cost of having a Master Craftsman Design and Build the duct work.

And don’t forget number 4:

They often create a bunch of RF noise as they ramp up and down.

The FCC has shown little interest in enforcing regulations here ?

 

[E. Bryan Hoover]

I'll remember to only buy an inverter fridge where the manufacturer specifically states their compressor and internal fan speed have been taken into consideration as part of the normal design and testing process.

Oh wait, that'll be all of them.

And the salesman thanks you...

You, "gnubie", are his kind of customer.

 

[HaldorEE]

Very interesting. I suppose if you tried a simple single-to-three phase conversion you wouldn't have frequency control, hence the rectification to DC, then inversion to three-phase AC. Very cool (and very pun-tastic).

Basically it has a 3 phase synchronous motor drive controller built into. These ramp up motors by applying lower voltage at lower frequency and gradually increasing both as the motor starts up. Synchronous motor speed is controlled by frequency, not voltage. Very cool (joke intended) technology.

 

[Ampster]

And the three phase motor technology was invented by Nicola Tesla over a hundred years ago.

 

[HaldorEE]

And the three phase motor technology was invented by Nicola Tesla over a hundred years ago.

And we still use it since nothing is better.

Actually his initial invention was two phase. Three phase was a later improvement. A 3 phase synchronous motor is an amazingly efficient way to convert electrical energy into mechanical energy. Works equally well in the other direction too.

Probably the single most important invention of the 19th century.

 

[tictag]

Probably the single most important invention of the 19th century.

I watched "The Current War" recently, very interesting. Not sure how much was based on fact, but interesting nonetheless.

 

[HaldorEE]

I haven't seen that. Tesla's life reads like a blockbuster movie. Self assured young genius makes his way to the top, overturning the establishment in the process. Wins huge only to end up loosing it all pursuing a doomed dream. Ends up dying in obscurity a broken man virtually forgotten by the mass millions who's lives he has quite litterly enlightened.

Edison's electric power was only for the ultra rich. Tesla made electricity real for the rest of us.

As an electrical engineer, I consider Tesla to be on the same level as Newton and Einstein both for the power of his intellect and the effect he has had on the world.

 

[tictag]

Tesla does make a prominent appearance in the movie, though it's not strictly about his life. In the movie he is well and truly f'ed over.

Another interesting movie that involves Tesla to a lessor degree is "The Prestige", more of a fantasy/sci-fi than documentary.

And apparently there's a new 2020 movie simply titled "Tesla" with Ethan Hawke. I haven't seen this.