I'd like to unplug my fridge for a few hours each evening to have silence in my small studio while I fall asleep. It is on a timer, so it happens at random times through the cooling cycle. I was warned that this could be a problem if I unplug the compressor while it is running, and perhaps I'm supposed to turn the temperature down/off for 30 minutes first.
Can anyone confirm this? Is there anything else I need to be aware of when unplugging the fridge?
When you short cycle the compressor like that it's the worst thing an owner can do to shorten the lifespan of it's compressor.
The refrigerator compressor uses oil to lubricate the pump. This pump runs very hot. The oil becomes dirtier and dirtier as it travels through the refrigerator tubes and clogs the refrigerant paths making it impossible for the refrigerator to cool. When you short cycle the fridge, it immediately kills the pressure behind the oil from the compressor, and the oil in the pathways must trickle back to the reservoir. with only gravity assistance, so the thicker the oil is the less likely it is to make it back without clogging.
However if you must turn it off in order to sleep, turn the cold temp to off prior to turning the fridge off. All fridge manuals recommend that you do this before unplugging the fridge when moving the fridge. This will help keep the oil flowing back to the reservoir.
Two thoughts from this peanut in the gallery:
Make sure whatever timer you have is designed to handle the load being pulled by the refrigerator. I'm pretty sure this is one of the top power users in the house, behind any heating systems (dryer, oven, electric heaters) and probably behind a central AC system. Using a cheap timer designed for a lamp would likely destroy the timer, if not cause a fire.
Many devices with compressors (fridge and AC) include a delay switch to avoid restarting shortly after it was turned off. The restart without enough time from the last run is what really kills them. The reason I was always told to avoid the short cycle was because the motor may have a difficult time restarting when the system is pressurized, and it would burn itself out trying to overcome that differential. In other words, the short cycle issue I know of is when you turn it off and then back on, not on and then back off.
So, to get to the point, you may not have any issues if the timer leaves the fridge off for at least 15 minutes before turning the power back on. And on a model with a working delay switch, you may not have any issues if you return power even sooner. But this is just my opinion, and it wouldn't hurt to get a few more before trusting me.
