Owners of household appliances are often faced with a situation where, when starting the refrigeration unit light flashes or, in the worst case, the circuit breaker in the panel trips. This is a direct consequence of the fact that starting current significantly exceeds the rated electricity consumption in operating mode. For equipment of the Belarusian brand Atlant, which is widely distributed in the CIS, this parameter is critical when choosing protective automation and voltage stabilizers.
Understanding the physics of the process is necessary for everyone who wants to protect their wiring. When the compressor is turned on, the piston is stationary, and colossal energy is required to overcome inertia and create initial pressure in the system. It is in these fractions of a second that a short-term but powerful jump in consumption occurs, which is called the inrush current.
Many users mistakenly believe that if a refrigerator consumes 150-200 watts per hour, then the wiring should only withstand this load. However, the reality is that in the first moments of operation, the load on the network increases by 3-5, and sometimes 7 times. Ignoring this fact when installing an electrical network in a house or apartment can lead to overheating of contacts and fire hazards.
Physics of the process: why overload occurs
The main heart of any refrigerator, including popular models Atlant MXM 2808 or Atlant 4008is compressor An electric motor is located inside it, which drives the piston group. At rest, the motor rotor is immobilized, and to spin it up it is necessary to overcome static friction and refrigerant pressure in the system.
At this moment, the resistance of the motor windings is minimal, which leads to a sharp surge of current. Inductive reactance has not yet had time to increase to operating values, and the network releases the maximum charge. This process usually lasts from 0.5 to 3 seconds until the rotor reaches the required speed.
It is worth noting that modern inverter models behave differently, but classic ones with single-phase asynchronous motors are fully susceptible to this effect. If at the moment of starting the voltage in the network is reduced, the acceleration time of the motor increases, which prolongs the action of the high current and can lead to overheating of the windings. Atlanta with single-phase asynchronous motors are fully susceptible to this effect. If the mains voltage is reduced at the time of start-up, the motor acceleration time increases, which prolongs the effect of the high current and can lead to overheating of the windings.
⚠️ Attention: Frequent starts of the compressor with a high starting current at low voltage in the network is the main reason for the interturn short circuit and the motor exiting building.
It is important to distinguish between the rated current indicated on the device tag and the peak values. The rating shows the average consumption during stable operation, when the refrigerant is already circulating and the pressure in the system has equalized. The peak value is an emergency mode of operation of the electrical part of the engine, which is inherent in the design, but requires control.
Real indicators for Atlant models
To determine exactly which one starting current is typical for your refrigerator, you need to refer to the technical documentation or the tag on the back wall. However, the average data for most models Atlant with compressors with a volume of 36 cm³ (standard for two-chamber models) look predictable.
Usually the operating current of such compressors is about 0.8–1.2 Amperes. Based on this, the starting surge can reach 6–10 Amps depending on the condition of the engine and the ambient temperature. For more powerful models, such as Atlant 600 series with two compressors, the total load with the simultaneous (theoretical) start of both motors would be critical, but the electronics space their start in time.
Below is a table with approximate data for popular series. Please remember that actual values may vary depending on the year of manufacture and the specific compressor manufacturer (for example, Atlant, Secop or Embraco).
| Series / Model | Compressor power | Operating current (A) | Starting current (A) |
|---|---|---|---|
| Atlant MKhM 1700 | 1/8 hp | 0.7 - 0.9 | 3.5 - 4.5 |
| Atlant MKhM 2808 | 1/5 hp | 1.0 - 1.2 | 6.0 - 7.5 |
| Atlant MKhM 4008 | 1/5 hp | 1.0 - 1.2 | 6.0 - 7.5 |
| Atlant MKhM 6021 | 1/4 hp (two) | 1.3 - 1.5 (each) | 8.0 - 9.0 (each) |
As can be seen from the data, even for powerful models the values do not go into space, but they are quite capable of creating a load that is noticeable for weak wiring. This is especially true for old houses, where aluminum wires could degrade over time.
The influence of inrush currents on the electrical network
A sharp jump in energy consumption does not leave its mark on the home electrical network. The contacts of sockets and plugs are the first to suffer. If there is oxidation or weakening at the junction, high inrush current causes sparking and local heating. Over time, the plastic melts and the contact disappears completely.
The second is automatic switches. Modern machines have thermal and electromagnetic protection. A serviceable class "C" circuit breaker should withstand a short-term surge of 6-10 Amps without breaking the circuit. However, if the machine is old or selected end-to-end (for example, at 6A for the circuit where the refrigerator and kettle are located), it can knock out exactly at the moment the motor starts.
It is also worth considering the effect on other devices. A voltage drop at the moment of starting the compressor Atlant can lead to flickering of incandescent lamps or rebooting of the sensitive one. electronics connected to the same line. This is especially noticeable if a refrigerator and, for example, a computer or TV are sitting on the same branch.
The greatest risk arises when using extension cords with thin wires and poor contacts. This creates a real risk of fire, since the insulation is poor. designed for such operating modes.
⚠️ Attention: Never connect the refrigerator to the network through cheap household extension cords without overload protection. This is one of the most common causes of fires in the kitchen.
How to protect equipment and wiring
To minimize the risks associated with high starting voltages currents, there are several proven methods of protection. The first and most important is the correct organization of wiring. The socket for the refrigerator should be separate, preferably with a ceramic contact base, and connected directly to the panel.
The second effective method is to install a voltage control relay. This device protects not from current surges, but from voltage surges in the network, which can aggravate the situation with the inrush current if the voltage drops below. 170V or rises above 250V, the relay will turn off the power, preventing the engine from operating in emergency mode.
☑️ Checking the connection safety
The third option is to use a voltage stabilizer. refrigerator Atlant it is better to choose models with an electromechanical or inverter operating principle, as they provide smooth adjustment. It is important to select a stabilizer with a power reserve, taking into account the starting characteristics.
Many modern models of stabilizers have a switch-on delay function. This is a critical parameter. After turning off the power, the compressor needs time. (usually 3-5 minutes) so that the pressure in the system equalizes. If you turn it on immediately, the starting current will be even higher, and the load on the mechanics will be critical.
Problems with starting: when the current becomes dangerous
There are situations when starting current becomes abnormally high or the engine cannot start at all, only humming and consuming short circuit current. This indicates a malfunction. One of the common reasons is the failure of the starting relay.
The starting relay is a small black box on the side of the compressor. Inside there is a coil and contacts. When voltage is applied, the coil creates a magnetic field that draws in the core and closes the contacts of the starting winding. If the relay is “stuck” or the coil is burned out, the engine will hum, consuming a huge current, until the thermal protection relay trips or the wiring burns out.
Symptoms of a faulty starting relay
There is no characteristic click when starting; The compressor hums for 3-5 seconds and turns off; Restarting is possible only after a long time after cooling; There is no cold on the back wall of the refrigerator.
Another cause of problems is an interturn short circuit in the motor windings. In this case, the winding resistance drops and the current increases disproportionately. The compressor may start, but will operate with overheating and increased noise, consuming more electricity than required according to the data sheet for the model Atlant.
It is also worth mentioning the mechanical wedge. If the piston group is jammed due to lack of oil or foreign objects, the rotor is physically unable to turn. The current in the windings reaches its maximum instantly. In such cases, starting is impossible without major repairs or replacement of the unit.
Selecting a stabilizer and calculating power
When choosing a voltage stabilizer for a refrigerator Atlant many people make the mistake of focusing only on the rated power in Watts. This is not enough. It is necessary to take into account the total power in Volt-Amperes (VA) and the starting current ratio.
The calculation formula is simple: take the rated power of the refrigerator (for example, 200 W), multiply by the starting current ratio (take 5) and add a margin of 20-30%. Thus, for a refrigerator with a power of 200 W, you need a stabilizer that can withstand a short-term load of about 1300-1500 VA.
The optimal choice would be stabilizers with a power of 1.5 kVA to 2 kVA. Smaller values (500-800 VA) may not cope with starting the compressor, especially if the network voltage is already reduced. When the input voltage is low, the output power of the stabilizer drops, and the reserve may not be enough.
Pay attention to the response speed of the stabilizer. For refrigerators with their sensitive control electronics (in new models Atlant), smooth adjustment is important so as not to create additional interference. Relay stabilizers are cheaper, but they switch the windings in steps, which can be accompanied by micro-interruptions in the power supply, which are undesirable for the motor.
Diagnostics and measurements
If you suspect that the refrigerator consumes too much energy at startup, you can diagnostics. The simplest way is to visually inspect the start relay and check the temperature of the compressor housing after operation. If it is red-hot (not just hot, but incandescent), it means that the current in the windings is higher than normal.
For accurate measurements, you will need a current clamp with a Peak Hold function. A conventional multimeter will not have time to detect a short-term jump. The pliers are put on one of the power wires (phase or neutral) when the refrigerator is turned on.
We compare the obtained value with the passport data. If the actual starting current exceeds the rated current by more than 7-8 times, or if the engine starts on the third or fourth attempt (audible by the clicks of the relay), this is a reason to call a technician. Operating equipment in this mode will kill the compressor in a matter of weeks.
Can the starting current kill the Atlant compressor?
The starting current itself is the normal operating mode. However, if low voltage or a faulty relay prevents the motor from accelerating, the current remains high for too long. This causes heating of the windings, destruction of the varnish insulation and, ultimately, a short circuit. So the danger is not the fact of the jump itself, but the protracted start-up process.
Why does the Atlant refrigerator knock out the machine when turned on?
This happens if the total current in the circuit exceeds the rating of the machine. If a microwave or electric kettle is operating on the same line with the refrigerator, their total power plus the starting current of the refrigerator can exceed 16 Amperes (standard for many apartments). The solution is to separate the devices into different sockets or lines.
Do you need a stabilizer if the voltage in the network is stable?
If the voltage in your network is really stable in the range of 210-230V, and the wiring is new and of high quality, an additional stabilizer is not strictly necessary. However, it extends the service life of the control electronics and protects against rare but possible emergency surges in the external network.
Does the temperature in the room affect the starting current?
Yes, it does indirectly. In a hot room, heat exchange is worse and condensation pressure is higher. It is more difficult for the compressor to start and create the necessary pressure, which can slightly increase the duration of the starting current and the overall load on the motor. In addition, a hot engine has less winding resistance.