I have found, the motor runs for around 1/3 two 2/3 of the time with a good refrigeration unit, except for inverter drives where some regulate the speed of the motor, but with domestic even inverter drives regulate by switching on/off, the typical fridge/freezer uses around 70 watt on run, unless inverter drive 700 watt at start, and around 150 watt on the defrost cycle, so putting an energy monitor on the unit one can see how long the motor is running for, and how often any defrost element runs for.
92 kWh/annum / 365 = 253 watt/hours per day, so at 70 watt = 3.6 hours running per day, but the 70 watt is a guess, running on an energy monitor one should get a graph
this one is my battery charger, but it shows when there is a time when not running that the unit has not lost gas and is working as it should. If it has lost gas, it will not switch off, and one can see it has not switched off on the graph. The totals in this case my AC unit
give one a good idea if still running using around the rated annual use.
I did have a small freezer which was not switching off, in fact still have it. The question then was, has it lost gas, or the insulation failed, or is it going too cold (thermostat failed) I did not have a thermometer which went down to -18ºC, but that is the freezing point of brine, so mixed salt and water so saturated, stuck it in freezer, and it froze solid, showing the thermostat at fault. I got a new thermostat and my brewing thermostat arrived, so could now measure, and it had been going down to -26ºC and with new thermostat the unit still being used today.
However unit cost around £100 and a refrigeration guy call out was £65 for first hour, plus parts, and more if over an hour, so even with a cheap repair, one has to ask at those prices is it worth it? Clearly if a motor had failed, cheaper to buy new. And although I could transport it easy, they seemed to only work out of a van, there was no premises I could take the unit to.
