Big inverter fridges.

Regarding "LG(?) inverter refrigerators"... One service person out of Canada suggested that the LG inverter/fridges seem to last around 7 years +/- or something like 1/2 the life of a typical fridge.

Take that with a grain of salt.

That the one fridge has a 0.50 Power Factor--That is really sad--And in many countries would not be "acceptable" to national energy standards that require better than 0.8 or 0.9 (as I recall) PF standards.

Asking why PF matters... For the "average" grid customer--It really does not. The typical utility meter only "charges" for kWH (kilo Watt*Hours of energy used). So a (made up numbers) 300 VA (volt*amp) load * 0.5 PF = 150 Watt load (Watts=VA*PF).

AC power "math" is actually quite complex. And what happens in "real life" with power PF loads is complex too...

The sort of short answer... There are two major classes of PF issues. There are Linear PF issues and Non-Linear PF issues.

The Linear PF issues are (for example) standard induction motors that simply draw the current out of phase with respect to the voltage. Typically motors "look like inductors" where the voltage rises, then the current a few milliseconds later starts to rise). This type of PF issue can be corrected by the owner/customer/utility by installing capacitors (at the motor, out on the grid) to "correct poor PF").

To answer why this matters--Is that a 0.5 PF draws 2x more current than a "perfect" 1.0 PF load. So the wiring, transformer, generator, etc. has to be 2x larger to handle that "extra" current that does nothing useful. Also, remember that Power=I^2*R... So that 2x more current means 4x more losses due to heating of wires/transformers/etc. So for larger loads (office buildings, oil refinerys, etc.) are more efficient with "good PF" loads.

And for large/complex systems--There was the example of a credit car processing center (days of paper card receipts--As I recall). Had a bunch Personal Computers--Floors of them--and the building wiring was overheating even though the wring should have been large enough to support the rate power (Watts) of the computer loads. Also, in the case of the PCs with "non-linear" loads (next), this cause the 3 phase power to run wonkie and cause high neutral/currents) and cause more overheated wiring issues.

The non-linear poor PF of (typically computers/electronic system) power supplies is that the "front end" of those supplies use a a diode connected to a capacitor to convert 120/240 VAC to 340 VDC for the DC to DC conversion to low voltage for the electronics. This causes a "current spike" near the peak/crest of the AC voltage wave form, and zero current draw during the 80% of the lower voltages of the AC wave form.

This will cause a "power PF" just like the linear PF--However, this spike of current cannot be "fixed" by adding AC capacitors to the AC line (non-linear current flow).

Also these spikes have lots of "harmonics" or higher frequencies in them. The AC system, transformers, etc. are designed for 60 Hz (or 50 Hz) current... When the loads start injecting 120/180/240 Hz / etc.) current into those transformers, this causes circulating currents inside the transformers (and generators) which uses "current/Ampere capacity) and generates lots of waste heat (over heating).

Decades ago, the solution for electronic power supplies was to use Power Factor Corrected power supplies... The electronics now look like a "linear" load and do not "stress" the AC utility/inverters/generators. This is a well known issue and solution--For a "inverter-compressor" refrigerator mfg. to have poor PF designs is pretty much unforgivable.

-Bill