Power outages create two different problems for a refrigerator, and they should not be confused. The first concerns the appliance itself, since it is not the lack of electricity that damages the refrigerator, but the way that electricity returns. The second concerns the food, and completely different rules apply here.

Let’s look at both.

Why the Appliance Suffers

What is dangerous for a refrigerator is voltage going outside its operating range, both when it drops and when it rises. The consequences are specific. The motor can overheat and fail. A voltage surge can cause the compressor to seize. An insulation breakdown can occur. The electronics are also affected, since in modern models they regulate the compressor’s power, and they are often the first components to fail during voltage fluctuations. There is also a second technical reason, which is related not to voltage but to pressure inside the system. After the compressor stops, it takes time for the pressure to equalize, and if the motor tries to start immediately, it operates against high pressure, overheats, and may burn out. This is why the pause before switching it back on has a physical basis and is not just a superstition.

The Mass Start Effect

Here is an interesting point that explains why the problem can intensify on its own. Most refrigerators in a building remain permanently plugged into outlets, so after the power supply is restored, they start at roughly the same time. This creates a peak load on the electrical network, which can cause voltage spikes and drops, trigger the building’s protection systems, and in some apartments cause the power to go out again. In other words, your neighbors’ refrigerators can contribute to voltage fluctuations that then damage your refrigerator. If appliances started gradually at different times, the load on the building’s electrical network would be noticeably lower.

An Action That Costs Nothing

During a power outage, unplug the refrigerator from the outlet. After the electricity is restored, wait approximately five to ten minutes and only then plug it back in. This pause solves two problems at once, since during this time the pressure in the system has time to equalize, while the electrical network has time to stabilize after the simultaneous startup of other appliances in the building. If the outage occurred while you were away, follow the same rule when you return: do not switch the refrigerator on immediately, but give it some time.

Three Levels of Protection

Experts identify three methods, and they differ in price and capabilities.

A voltage protection relay is the simplest and cheapest option. It constantly monitors the voltage in the electrical network and immediately disconnects the appliance when the voltage goes outside the safe range, then switches it back on after a delay of approximately five minutes. This delay is what makes the relay useful, since it automates the pause that you would otherwise have to observe manually.

A voltage stabilizer not only disconnects the appliance in a critical situation but also regulates the voltage within its operating range, meaning that the appliance continues working during deviations that would otherwise cause a relay to activate.

An uninterruptible power supply is the most expensive solution because it not only protects against voltage fluctuations but also continues powering the refrigerator during the outage itself. Here it is important to remember that a refrigerator consumes several times more power than its rated consumption when the compressor starts, so the power supply must be selected according to its peak power, which I discussed in detail in the article about portable power stations.

Which Relay to Choose

For a single refrigerator, a plug-in version is usually sufficient, meaning a device that is plugged into the wall outlet, with the refrigerator then connected to the relay. It is simple to install and does not require any work on the electrical panel. If several refrigerators, a freezer, or powerful kitchen appliances are connected to the same circuit, a device designed for installation in the electrical panel on a standard DIN rail is more logical, as it protects the entire group of outlets at once. The second solution requires an electrician, but it protects more appliances.

Built-In Protection

Some manufacturers claim that their refrigerators have built-in protection against voltage fluctuations and surges. Specialists recommend not relying on it alone, since external protection is still necessary, and repairing or replacing a refrigerator costs significantly more than a voltage relay.

The logic is simple: a relay costs several hundred hryvnias, while a compressor costs several thousand.

About Inverter Models

Refrigerators with inverter compressors have a softer startup because they do not start abruptly at full power but gradually increase their speed. This reduces peak load and makes operation from a backup power source easier. At the same time, such models have more sophisticated electronics, which are themselves vulnerable to voltage surges, so the need for external protection does not disappear.

Now About the Food

A closed refrigerator maintains an acceptable temperature for approximately four hours. A completely full freezer can retain its cold for approximately two days, while a half-full freezer can do so for about one day. The main rule is not to open the door, since every opening reduces the amount of time the food remains cold. A full freezer retains cold better than a half-empty one, so empty space can be filled with bottles of water, which will act as cold accumulators. Thawed meat, fish, and prepared dishes should not be refrozen.

Food that has remained at room temperature for an extended period is better not consumed regardless of its appearance, since smell and appearance are not reliable indicators of food safety.

Early Signs of Problems With the Appliance

If the refrigerator has started clicking more frequently, humming noticeably louder, or running through longer cycles without pauses, these can be early signs of a malfunction. In such a case, it is more sensible to call a technician for diagnostics than to wait for a complete failure, since replacing an individual component is usually cheaper than replacing the compressor. The same applies if, after the power is restored, the refrigerator clicks every few minutes but the compressor does not start.


Sources

Comments by Candidate of Technical Sciences Andrii Yavorskyi for UNIAN, publications by OBOZ.UA, Glavred, Konkurent, and materials from refrigerator repair service centers.