LG INVERTER REFRIGERATORS

jtdiesel65

Dave Angelini said:

The link you gave petertearai  does not work in North America or ?  I know what you mean though about the climate. Our summer energy is much lower (heat pump cool) than winter when we have a fire at night.

Ever try measuring it over 24 hours jtdiesel65 ? About 1.6 for the one in the link below. My neighbor has one.

https://www.homedepot.com/p/LG-Electronics-25-50-cu-ft-Bottom-Freezer-Refrigerator-in-PrintProof-Stainless-Steel-with-Filtered-Ice-LRDCS2603S/312284005

It's on my list to measure. I'm currently chasing down overnight usage and that's one of the things I need to measure.

Dave Angelini

Optics and Insight cloud the Schneider version both depend on the calibration of the sensors. Schneider is all internal to the inverter.
What external, if any shunts are you using in the FX installation?

 It is not a big deal but an error is there when you inverting near 100 watts and the battery is full. Most never see this as it only shows up at night or ?

Add to your daily usage the loss of charging the battery also   Since your LG is rated at 300KWH for 16 cubic feet or 454 liters, it would be great to log a summer when it will work harder. Still seems amazing,  you are quite a bit under that for just one unit.

A typical North American 22 cubic foot unit is rated around 400KWH and if not too hot in summer can use around 1KWH per day. I use this for my design mid ground when I have to guess for an offgrid home. They have a start surge but that is pretty normal and not a problem for a home power system that has well pumps, air compressors, transfer pumps.

The LG 22 cu ft Inverter I linked a few years back is about the same usage without the surge.
As for food keeping longer, pretty subjective, and very hard to test. Sales marketing hype abound!

Dave Angelini

Below is how GE does their new electronic refrigerators. Kind of a dull read but maybe helpful. When one searches for an inverter based model, you often get alot of replacement electronic parts for the inverter. Another reason if you live in a remote place offgrid to stay with a standard compressor, or have a spare.

Additive Defrost

A defrost cycle burns a lot of energy; therefore, cutting down on the number of defrost cycles a refrigerators goes through can greatly increase energy efficiency of the refrigerator. Earlier models (and non-electronic models) have defrost timers which force a defrost cycle every 6-15 hours. At times it may be necessary for a defrost-cycle this frequently but others it is just a waste of energy to run a defrost cycle this often. The way this works on GE electronic refrigerator models is the main board monitors how frequently the doors to the refrigerator are opened, how long the doors to the refrigerator are opened and how long each defrost cycle takes to complete to adapt defrost cycles to its needs.

However, it doesn’t just go by these inputs. Lets say you go out and buy a lot of groceries and you leave the door to the refrigerator open for 30 minutes while loading the groceries. That 30 minutes is normally enough to trigger a defrost cycle; however, a defrost cycle will not occur until at least 8 hours has passed since the last defrost cycle. Therefore, there is a minimum of eight hours between defrost cycles. Now lets say you are out of town and the door stays closed. After 48 hours of the door being closed a defrost cycle will be initiated; therefore; the longest time between defrost cycles is 48 hours.

Now lets say you live in Florida where it is nice and humid, you are out of town (no door openings) and the door gasket is ripped letting all kinds of moisture into the freezer. With all this moisture there is no way that having a defrost cycle every 48 hours will be enough. This is true but what happens is the board will initiate a defrost cycle after 48 hours but then it takes 45 minutes to defrost. The board “says wait a minute that is way too long for a defrost cycle something must be wrong.” So the next defrost cycle is initiated in 8 hours to compensate for the ripped door gasket and high humidity. This is why they call it adaptive-defrost because it adapts to all different scenarios.

The defrost cycle will last until all frost is melted off the coils for a maximum time of 45 minutes. After each defrost-cycle there will be a 5-minute period where nothing is on so that all the moisture can finish dripping off the coils before the next cooling cycle begins. This page will help you with diagnosing a defrost problem on a GE electronic refrigerator model.

Refrigerator Defrost Problem

Pre-Chill

Pre-chill is a cycle that occurs just before a defrost cycle to drop the temperature in the freezer so that the temperature doesn’t rise so high above normal during defrost. This cycle is a continuous cooling cycle, which can drop the temperature to around –15 degrees and it lasts for two hours. During this time the damper controls the temperature in the fresh food section.

Liner Protection Mode

GE electronic refrigerator models have what is called a liner protection mode that is a mode that initiates after one of the doors has been opened for more than three minutes. In liner protection mode, the evaporator fan will run and the damper will close. This is why it is necessary to check the door switch operation if the fresh food section is not cooling because if the door switch isn’t working then this mode may have the damper closed preventing cold air from entering to cool the fresh food.

Cooling Cycle

During the cooling cycle, the main board monitors the thermistors until the temperature set point is reached then turns the compressor off. The compressor will run as long and as often as necessary to maintain temperature. During this time the fans will slow down and speed up as necessary. This page will help with thermistor diagnostics.

Testing GE Refrigerator Thermistors

Fan Motor Control

The fan motors are variable speed motors that are controlled by the motherboard. These motors operate off of 8-14 VDC. The motherboard monitors the temperature in the refrigerator and will slow down and speed up the fan motors as needed. This will save energy because the fan isn’t always running full-blast, as well as they draw less current than AC motors. This page will show how to test fan motors on GE electronic refrigerator models.

GE Electronic Refrigerator Fan Motor Diagnostics

Variable Speed Compressor

Some recent electronic refrigerator models take energy efficiency a step further by introducing variable speed compressors, which burn a fraction of the energy as your typical refrigerator compressor. These compressors make almost no sound and put off very little heat. They are sometimes called an inverter compressor because they need an inverter to operate. Both the inverter and the compressor still are controlled by the motherboard. This is roughly how it works. If the temperature in the freezer rises to 7 degrees above the set point then the compressor will run at high speed. When the temperature gets to within 6.5 degrees above the set point it will switch to medium speed. Then when it gets within 4 degrees above the set point it will switch to low speed and remain until satisfied.

Dual Evaporator

Combine a variable speed compressor with dual evaporator and you have the most energy efficient electronic refrigerator that GE has on the market today. This is what they did with the GE profile climate Keeper models. This system uses one compressor and two evaporator coils (cooling coils), as opposed to one compressor and one evaporator coil. The motherboard monitors the temperature in the freezer and the fresh food section and can precisely and accurately control the temperature. This is done by slowing/speeding up the compressor, slowing/speeding the fans and using a three-way valve shutting off/ opening up refrigeration lines to each evaporator separately. What this means is the compressor will continue to run until both sections are at the temperature set point but refrigerant may not be flowing into both evaporators at all times.

petertearai

Yes , i will test it over an extended time . I wonder how accurate the little plug in power meters are . As per usuall the plug in meter is where i last used it ( at work,) . So will just have to wait ,   we also have a GE inverter model fridge in the shops here , very similar usage specs and size . But a little more expensive , so i settled for a second fridge to match the first proven LG. ... Funny thing, when ever I'm out and shopping near an appliance store i can't help just checking the fridges   to see the energy usage. The sales people , are only slowly coming round to energy usage as a feature .  

petertearai

Just  had the power measuring thing on for  24 hours . .5 KW    .  Was already on ,  ambient temp 22 deg c . But my measurer  cost $25.00 so  don't know how accurate . Door opened  only about 10 times .

Dave Angelini

Pretty nice for a 16 cubic foot reefer. Very nice!   When you opened the door did you take wine out only

petertearai

Ahhh . Wine in other fridge.  Also i might add that nothing added to the fridge, that was warm . So it is not a real world test. Also note that the power factor on the meter reads 100% assume that is a power factor of 1 . Max watts reported was 187 watts , i think that was on the repluging of the fridge after plugging in the power meter ..

petertearai

Fridge used 3.5 kw over  7 days . 2 days in residence and 5 days with no one there  .

Dave Angelini

Wow that is nice! I can't find any LG in that size on this side of the pond that use less than 425 kwh per year. I have some clients that want something like yours that can get by on 1/2 a kwh per day.
https://www.lowes.com/pd/LG-14-7-cu-ft-Bottom-Freezer-Refrigerator-Platinum-Silver-ENERGY-STAR/1001163520


Post the model link again please if you can.