Although what you say is qualitatively correct, I suspect that you have rather an optimistic degree of faith in the 'energy usage rating', and also are probably assuming a degree of predictability of actual energy usage which does not exist. How much energy a refrigeration appliance will actually use will vary appreciably by virtue of a whole host of factors - such as ambient temperature, how full it is, how often the door is opened (and for how long) etc.etc.
Kind Regards, John
After having the problem I have tested my units on a regular basis, well around once a year, they are over the rated figures, but not by that much, did have a little 32 litre freezer using well over the rating, the motor running used something like 60 watt and average usage was 60 watt, i.e. motor never switched off, there is two likely causes for this, one is insulation failure, the other is thermostat failure, so wanted to measure the temperature inside the freezer, I tried all local shops, nothing, I had sent for a stand alone thermostat to control a fridge for beer making and once that arrived I could use it to both measure and control if required, but wanted some thing in the mean time to test temperature.
Then read freezing point of brine is -18°C so dissolved some salt in water to saturation point, put it on shallow dish and in freezer, it froze solid, so clear thermostat not insulation and ordered a new one, when the unit for brewing arrived use that temporary to control freezer, when proper unit arrive fitted it and tested with the brewing unit, the thermostat had to be set to coldest point to get -18°C in freezer, not sure if due to sensor position or what. So tested all other freezers in the family they were all OK.
Today the fridge and freezer reports temperature when door is opened and is set in degrees C, however all the older units had simple high, med, low which was not really satisfactory, same with TRV's on central heating *123456 what's point in that? want degrees not worried if in F or C or even K but high med low does not cut it. So yes admitted with older units before they had LCD displays to show temperature, so on power cut it shows highest temperature reached before power returned etc. There as a problem, however still if you know the unit is using well over rated power, then you can start looking at why, and do further tests, but to take a stab in the dark and replace bits that could be faulty could end up expensive and not cure the problem.
When I found the thermostat was faulty, tried to buy one local, at 32 litre only easy enough to put in car and take for repair, could not find anywhere to take it to, or buy parts, they would come out to repair at £60 for first hour plus spares, the whole unit only cost £90 new.
Our Samsung has a 10 year warranty parts and labour on the motor and inverter, but not the body. I am sure the old Hoover was damaged from new, but how would you prove it, and it did run for a good 15 years before real fault found. Plus another 4 as brewing fridge after, only scrapped when we moved house.
