A power outage often takes you by surprise, jeopardizing the safety of food in the freezer. To prevent food spoilage and ensure a comfortable pastime, many are thinking about purchasing an autonomous energy source. However, the simple question “how much power is needed for a generator for a refrigerator and TV” hides many technical nuances, ignoring which can lead to the failure of expensive equipment.
Many users mistakenly believe that it is enough to simply add up the power consumption of all devices to get the desired value. In reality, the electrical network and electrical appliances behave in a much more complex manner, especially during startup. An incorrect calculation will lead to the fact that generator it will work at the limit of its capabilities or even go into defense when trying to turn on the compressor.
In this article we will analyze in detail the physics of the processes that occur when starting up equipment, and will help you choose the optimal equipment that will last for many years.
Power consumption of the refrigerator and TV in normal mode
The first step to understanding the required power is to analyze the energy consumption of each device in normal operation. The refrigerator, despite its impressive size, consumes relatively little electricity, since its compressor operates cyclically.
Modern models of the energy efficiency class A++ or A+++ in operating mode consume from 100 to 200 W. Old Soviet units or models with the system No Frost may require 300–400 W.
TVs also vary greatly in consumption. A small LED screen consumes about 30–50 Watts, while large OLED or plasma panels can consume 150–300 Watts depending on the brightness and contrast of the image. The total operating power of the bundle usually does not exceed 500 W, which seems negligible.
⚠️ Attention: It is absolutely impossible to focus only on operating power. A generator selected close to the operating values will burn out or turn off the first time the compressor is started due to starting currents.
It is important to consider that the rating data on the back wall of the devices often indicate the average annual consumption or maximum load. For accuracy, it is better to use a power meter connected to the outlet to see the real numbers of your equipment.
The phenomenon of starting currents and their effect on the generator
The most critical moment for any electrical network is the start of the electric motor. In the refrigerator, the compressor, which is an asynchronous motor, is responsible for cooling. At the moment of switching on, the motor rotor is stationary, and colossal energy is required to spin it up.
The starting current can exceed the rated current by 3, and sometimes 7 times. This means that a refrigerator that uses 200 watts when running will require 1000-1400 watts in a split second when starting up. If the generator is not able to produce this short-term surge, the voltage in the network will drop sharply.
TVs, especially modern models with switching power supplies, are characterized by high inrush currents for charging capacitors. Although they last less than engine spin-up, they cannot be ignored when calculating the total load.
There is a concept starting current coefficient. For refrigerator compressors it is usually 3.5, for some models - up to 7. It is this multiplier that is key when choosing the power of the unit.
Why does the light go out when the refrigerator is turned on?
This happens when the cross-section of the wiring or the power of the energy source is insufficient to cover starting current. The voltage drops below the permissible minimum, and the lamps go out for a split second.
The difference between active and reactive power (kW and kVA)
When choosing a power plant, you will be faced with two units of measurement: kilowatts (kW) and kilovolt-amperes (kVA). Many people mistakenly consider them equal, but this is not so. Active power (kW) is energy that directly performs useful work (heats, lights, rotates).
Reactive power (kVAr) is necessary to create electromagnetic fields in motors and transformers. It does not do any useful work, but circulates in the network, creating additional load on the generator. Apparent power (kVA) is the geometric sum of active and reactive powers.
The refrigerator has a reactive component due to the presence of an electric motor. The power factor (cos φ) for such devices is usually 0.6–0.8. This means that if the generator says 1 kVA, then it will produce only 0.6–0.8 kW of useful active power.
| Load type | Device example | Coefficient (cos φ) | Ratio kW/kVA |
|---|---|---|---|
| Active | Incandescent lamp, kettle | 1.0 | 1 kW = 1 kVA |
| Inductive | Refrigerator, pump | 0.6 - 0.8 | 1 kW ≈ 1.4 kVA |
| Capacitive | Power supplies for TV, PC | 0.6 - 0.9 | Depends on the circuit |
When calculating, always start from the total power of the generator in kVA, if the manufacturer has not separately indicated the active power for inductive loads. A safety margin is required here.
Calculating the required power: formula and examples
To understand which generator you need, you need to make simple mathematical calculations. Let's take a standard situation as an example: a refrigerator with a power of 200 W and a TV with a power of 100 W.
First, let's calculate the starting power of the refrigerator. We multiply 200 W by the safety factor (take the average value of 4). We get 800 W. A TV, as a rule, does not have such high inrush currents, but let’s add a 20% reserve to its power: 100 W + 20% = 120 W.
We sum up the peak values: 800 W (refrigerator start) + 120 W (TV operation) = 920 W. This is the minimum power that the generator must produce when the refrigerator is turned on. However, this is a theoretical minimum, which does not take into account equipment wear and fuel quality.
⚠️ Attention: Never choose a generator with a power “close” to the calculated one. The optimal power reserve should be 20–30% of the calculated amount. This will extend the life of the power plant engine.
The final formula looks like this: P_gen = (P_cold K_start) + P_TV + 20% reserve. For our example: (200 4) + 100 = 900 W. Add 30% reserve: 900 + 30% = 1170 W. Therefore, you need a generator with a power of at least 1.2 kW (or 1.5 kVA).
☑️ Check before purchase
Inverter generators versus classic ones: what to choose
The market offers two main types of gasoline power plants: classic (frame) and inverter. For powering sensitive electronics, such as modern televisions and electronically controlled refrigerators, this difference is critical.
Classical generators produce current with a sinusoid, the quality of which depends on the stability of the engine speed. When the load changes (turning on the refrigerator), the speed can “float” leads to surges in voltage and frequency. This is dangerous for electronics.
Inverter generators first generate high-frequency current, rectify it and then convert it back into an alternating current with an ideal sine wave. They are equipped with a system AVR (automatic voltage regulation), which smoothes out any fluctuations.
In addition. In addition, inverters can change engine speed depending on the load, which saves fuel and reduces noise. For a summer house or home where you need to power a refrigerator and TV, an inverter model with a power of 1.5–2 kW will be the best, albeit more expensive, solution.
Rules for connecting and operating equipment
Correct connection is the key to long service life of the equipment. You can't just plug plugs into generator sockets. First you need to start the generator itself, let it warm up for 2-3 minutes and stabilize the speed.
You should turn on the devices one by one. First, turn on the TV and make sure it is stable. Then turn on the refrigerator. Turning on both devices simultaneously will create a total starting current, which may be too high for a low-power station.
Use high-quality extension cords with a wire cross-section of at least 1.5 mm² (preferably 2.5 mm²). Thin wires over long distances create a voltage drop, which is compensated by the generator by increasing the current, leading to overheating.
For refrigerators, the frequency of the current is extremely important. The motors are rated at 50 Hz. If the generator produces 48 or 52 Hz, the compressor may not work correctly, hum, or overheat. Inverter models maintain the frequency with an accuracy of 0.1 Hz.
Frequently asked questions (FAQ)
Is it possible to connect a refrigerator to a generator without a stabilizer?
If you have an inverter generator with an AVR system, then a stabilizer is not needed - it is already built into the circuit. If the generator is ordinary (frame), then voltage surges can damage the compressor or the refrigerator control board. In this case, the use of an external stabilizer or UPS (uninterruptible power supply) is highly desirable.
Why does the generator stall when the refrigerator is turned on?
Most likely, the power of the generator is not sufficient to cover the starting current of the compressor. Also, the reason may be clogged fuel filters, incorrect carburetor settings, or the use of low-quality gasoline, due to which the engine cannot quickly gain speed under load.
How long can a refrigerator run from a generator?
The operating time depends on the volume of the fuel tank and engine consumption. A low-power inverter (1-2 kW) in economy mode can consume about 0.5–0.8 liters of gasoline per hour when the compressor is running. A 4-liter tank is enough for about 5-7 hours of continuous operation.
Is it necessary to ground the generator when connecting a refrigerator?
Yes, grounding is necessary. This is protection against electric shock in the event of an insulation breakdown on the generator or device housing. In field conditions, they often use a metal pin driven into the ground, to which a grounding terminal is connected.