Situations when it is necessary to turn off the power to household appliances arise quite often: moving, general cleaning, scheduled maintenance or a sudden power outage. Many owners do not even think about what processes occur inside the unit at the moment it is turned off and on, considering this to be an ordinary procedure. However refrigeration equipment the structure is more complicated than it seems at first glance, and ignoring physical laws can lead to serious damage.
In this article we will analyze in detail what exactly happens to the refrigerant and oil in the system when you pull the plug out of the socket, and why the rush to this issue is unacceptable. Understanding these processes will help extend the life of your Liebherr, Bosch or any other unit, avoiding expensive compressor repairs.
Physics of the process: state of refrigerant and oil
In the operating state of the refrigerator freon circulates in a closed circuit, transitioning from a gaseous state into liquid and back. The moment you unplug the appliance, the compressor stops building pressure, but the circulation of refrigerant and oil does not stop immediately. Drops of oil remain in the tubes of the evaporator and condenser, which should normally return to the engine crankcase.
If you try to turn the unit back on immediately after turning off, you may encounter an effect hydraulic hammer. The oil that has not had time to drain into the compressor is in the system in the form of an emulsion or suspension. Starting the engine at this moment creates a colossal load on the valves and piston group, since the liquid, unlike gas, is not compressed.
Where does the oil go when it stops?
When the compressor stops, the oil, which was under high pressure in the discharge line, starts slowly drain back into the engine crankcase under the influence of gravity. This process takes from 5 to 15 minutes, depending on the design of the system and the viscosity of the lubricating fluid.
In addition, a sudden change in pressure in the system can cause liquid refrigerant to enter the compressor suction pipe. For modern inverter models, such as Samsung Digital Inverter or LG Linear Compressor, this is especially critical, since their design involves working with certain environmental parameters at the input.
Why you can’t turn on the refrigerator immediately after turning it off
The most common mistake is to turn off the device, rearrange it or wipe it, and here or plug it into the network. Equipment manufacturers in the instructions for models Indesit, Atlant and other brands indicate the need for a pause. This time is required to equalize the pressure in the system and drain the oil.
If this rule is neglected, the compressor will start “dry” or with a liquid plug. This leads to rapid wear of mechanical parts, overheating of the electric motor windings and, in the worst case, to jamming of the piston group. Repair in this case often requires replacing the entire unit, which is not economically feasible.
⚠️ Attention: The minimum waiting time before turning it on again is 10–15 minutes. If the refrigerator was transported lying down, the waiting time increases to 3–4 hours for the oil to completely return to the crankcase.
It is also worth considering the state of the electrical network. If a powerful consumer is suddenly switched on immediately after switching off, voltage surges may occur that are dangerous for electronic control module. Modern protection systems can block the start, requiring a complete power reset, which again brings us back to the need to pause.
Impact on food: temperature conditions and bacteria
Disconnecting the refrigerator directly affects not only equipment, but also the safety of food. After removing the cord from the socket, the temperature in the chambers begins to rise. The speed of this process depends on the quality thermal insulation, quantity of products and external temperature.
It is important to remember the “two-hour rule”: perishable products (meat, dairy products, ready meals) should not be in the temperature zone from +5°C to +60°C for more than two hours. Otherwise, active proliferation of bacteria begins, making the food unsafe for consumption.
- 🥩 Meat products they begin to deteriorate first, and after 1.5–2 hours at room temperature, irreversible processes can begin in them.
- 🥛 Dairy products sours faster than the date on the package indicates, if the temperature was broken.
- 🥦 Vegetables and fruits are more stable, but loss of moisture (shrinkage) during defrosting makes them sluggish and less healthy.
If you are planning a long shutdown, for example, during a vacation, it is recommended to completely empty the chambers of food, defrost and wash the unit. Products left turned off will become an ideal environment for mold, the smell of which is then very difficult to remove from plastic panels and seals.
The correct procedure for shutting down and preparing for transportation
To minimize risks to equipment, it is necessary to follow a clear algorithm of actions. It doesn’t matter what model you have: huge Side-by-Side or compact Schäffler, the physical principles are the same for all.
First, you should remove all products and shelves. Glass shelves may break due to changes in temperature and vibration during transportation, so it is better to wash them separately. Then you need to wait for complete defrosting if your model does not have a system No Frost, although periodic washing will not hurt it either.
☑️ Checklist before turning off
After defrosting and washing, let the unit dry. It is better to leave the doors ajar to allow air circulation to prevent mold from forming. If transport is to be carried out, ensure that all removable parts are secured or packed separately. The compressor must “settle” before transportation, especially if you plan to put a refrigerator.
Comparison of consequences: short-term and long-term shutdown
The effect of blackout on equipment varies depending on the duration of the downtime. A short shutdown (a few minutes or hours) mainly affects the thermodynamics of the system and the condition of the oil. Long-term storage of a switched-off unit carries other risks associated with seal materials and electronics.
The table below shows the main risks depending on the downtime:
| Duration of downtime | Risk for the compressor | Risk for products | Recommended action |
|---|---|---|---|
| Less than 5 minutes | High (oil not glass) | Minimum | Wait minimum 15 minutes |
| 1–4 hours | Medium (pressure equalization) | Critical (food spoilage) | Dispose of perishables |
| 1 day - 1 month | Low | Absent (if empty) | Store with the door open |
| More than 6 months | Medium (lubricant hardening) | Absent | Checking seals before starting |
As can be seen from the table, the critical moment for mechanics is the first minutes after switching off, and for content - the period after reaching the temperature limit of +5°C. Long downtime requires checking the elasticity of rubber seals, which can “remember” the compressed position or dry out.
Features of modern control systems during power surges
Modern refrigerators are equipped with complex electronics. Models from brands Siemens, Electrolux and others have digital modules that control not only the compressor, but also fans, defrost heating elements and displays. A sudden switch-off and switch-on may be perceived by the controller as an emergency situation.
In some cases, errors may need to be reset. This is done through a long blackout (more than 30 minutes) or through a special combination of buttons described in the manual. If, after turning on, extra indicators light up or a squeak is heard, the system may have gone into protection mode.
⚠️ Attention: If after turning on the refrigerator hums, but does not cool, or makes clicking noises, turn it off immediately. Restarting is possible only after an hour. If the situation repeats, call a technician.
It is also worth considering that frequent power outages in the network can shorten the life of the compressor. To protect expensive equipment, it is recommended to use voltage stabilizers or voltage control relays, which cut off the power when the network parameters go beyond acceptable limits.
Frequently asked questions (FAQ)
Is it possible to turn off the refrigerator at night to save electricity?
It is strictly not recommended. The refrigerator operates cyclically: it turns on when the temperature rises and turns off when it reaches the set temperature. By turning it off at night, you allow the temperature inside to rise, and in the morning the compressor will have to work hard for several hours in a row to cool the entire volume. This will lead to excessive energy consumption and wear of the motor, and the food may spoil.
What happens if you turn on the refrigerator immediately after defrosting without drying it?
Moisture inside the chambers can cause a short circuit in electrical circuits, especially in the area of the lighting lamps or thermostat. In addition, excess water freezing in the drainage system or on the evaporator can interfere with normal air circulation and system operation. No Frost.
Do you need to remove the plug from the outlet during a thunderstorm?
Yes, this is a reasonable precaution. A direct lightning strike or a power surge during a thunderstorm can burn out the electronic control module. If you cannot physically turn off the device, use a surge protector with surge protection.