Correct adjustment of climate parameters in professional refrigeration equipment is the foundation for maintaining the commercial quality of products. Owners of shops, warehouses and restaurants are often faced with the need to change the standard factory settings of the thermostat Polair to adapt to specific operating conditions. Incorrectly set values can lead to both damage to perishable products and excessive energy consumption or compressor breakdown due to frequent switching cycles.
Modern refrigeration cabinets and chambers Polair are equipped with electronic controllers that require careful handling during calibration. Unlike household analogues, it uses a more complex operating logic, including hysteresis, defrost cycles and motor protection. Understanding the principles of operation of these systems allows you not just to “turn the screws”, but to build an effective temperature regime that extends the service life of the unit.
In this material we will analyze in detail the algorithms for setting up various models of controllers installed on equipment of this brand. You will learn how to enter the service menu, correct sensor errors and avoid typical mistakes made by inexperienced users during initial startup or seasonal reconfiguration of equipment.
Basic principles of operation of Polair controllers
The main control element in the refrigeration cabinet is electronic controller, which continuously reads readings temperature sensor. Based on the data received, he makes a decision to turn the compressor on or off. In equipment Polair most often there are models of series regulators EVCO or the plant's own developments, such as DX-series. Their main task is to maintain a given setpoint with a minimum error.
The key parameter in the operation of any thermostat is hysteresis. This is the temperature difference between the moment the compressor turns on and off. For example, if the temperature is set to +4°C, and the hysteresis is 3 degrees, the compressor will turn off at +4°C, and will start again only when the air in the chamber is heated to +7°C. Too little hysteresis will lead to “jerking” of the relay and rapid wear of the starting-protective device.
It is important to understand the difference between air temperature and product temperature. The sensor in cabinets Polair usually measures the air temperature in the upper part of the chamber or on the evaporator. To accurately control the temperature of the product, it is necessary to take into account the cooling inertia, which can be from 30 to 60 minutes after the change settings. Therefore, you should not expect an instant change in the readings on the display immediately after adjustment.
⚠️ Attention: Before starting any manipulations with the controller settings, make sure that the chamber door is tightly closed and there are no warm foods inside that could distort the sensor readings during the calibration process.
The logic of the controller is also tied to defrosting cycles. In models with system No Frost or static cooling, the algorithm can forcefully stop cooling to defrost the evaporator. If you try to change the settings at this moment, the controller may ignore the commands or reset them after the cycle is completed.
Defining the thermostat model and entering the menu
The first step before adjusting the temperature is to identify the installed controller model. The appearance of the control panel may differ depending on the year of manufacture and series of equipment Polair. Typically, a sticker with the model (for example, DM 201, EVK 412) is located on the front panel or inside the case next to the board. The set of available parameters and the key combination for entering the menu depend on the model.
The standard procedure for entering the programming mode is as follows: you need to press and hold the button SET for 3-5 seconds. The designation of the first parameter should appear on the display (often P0 or F1). If instead the alarm indicator lights up or the temperature flashes, the input is locked or a password is required.
Some industrial versions of controllers Polair have a level of protection against unauthorized access. In this case, after holding down the button SET the device will request a code. The default factory password is often 0000, 1111 or 3333, but it may have been changed by the previous owner or service department. Navigation through the parameters is carried out using the “up” and “down” buttons, and the choice of value is confirmed by a short press SET.
Step-by-step configuration of basic parameters
After successfully entering the programming menu, the user has access to the list of parameters. The menu structure may vary, but the basic settings are universal for most controllers Polair. Below is a table describing the main parameters that need to be checked and adjusted.
| Parameter | Description | Recommended value (Cold) | Recommended value (Frost) |
|---|---|---|---|
St (Set Point) |
Target temperature | +2...+5 °C | -18...-22 °C |
di (Differential) |
Hysteresis (on/off difference) | 2...3 °C | 3...5 °C |
Cr (Correction) |
Correction of sensor readings | 0 °C | 0 °C |
td (Delay) |
Compressor start delay | 3 min | 5 min |
To change value of the parameter, select it using the navigation buttons and press SET. The numbers will start flashing. Use the arrows to change the value. After setting the desired number, press again SET to save and move to the next parameter. Exiting the programming menu usually occurs automatically if no action is performed for 10–15 seconds, or forcefully by long pressing the exit button.
Particular attention should be paid to the correction parameter (Cr). If your thermometer shows +6°C, and the controller Polair “sees” +4°C, you need to set the correction to +2°C. This will align the readings and ensure proper operation of the automation. Without this procedure, the refrigerator may not operate correctly, believing that the norm has been reached when it is actually warmer in the chamber.
☑️ Check after setting
Setting defrost and defrost cycles
In refrigerators with a system No Frost or static cooling is critically important correct setting of evaporator defrost cycles. Ice freezing on the heat exchanger reduces cooling efficiency and can lead to fan failure. Controllers Polair allow you to flexibly adjust the frequency and duration of these cycles.
The main parameter here is the interval between defrosts (Id). The factory setting is often 6 or 8 hours. If foods with a high moisture content are stored in the chamber (for example, open containers with liquid, unpackaged meat), it is recommended to increase the defrosting frequency (reduce the time interval) so that ice does not have time to accumulate. However, too frequent defrosting will lead to an increase in the average temperature in the chamber.
The defrosting duration (Md) is the maximum time that the heating element can operate in one cycle. Usually this is 15–20 minutes. It is important not to set the value too high, since if the defrost end sensor fails (if it is provided for in the design), the heating element will heat until the timer expires, which can damage the plastic elements of the chamber. Optimal duration is selected experimentally: it should be sufficient for complete drainage of water, but not excessive.
⚠️ Attention: When setting the defrost time, keep in mind that in winter the air humidity is lower and less ice is formed. In the summer, especially in hot rooms, the intervals between defrosts should be shortened.
There is also a waiting parameter after defrosting (dp). It determines the time during which the compressor does not turn on after the heating element has finished operating. This is necessary so that the residual heat from the heating element does not immediately enter the chamber and cause a temperature jump. For equipment Polair the standard value is 2–4 minutes.
Diagnostics of faults through error codes
Controllers Polair have a developed self-diagnosis system. If a malfunction is detected, an error code appears on the display instead of the temperature. Understanding these codes helps to quickly determine why the temperature is not regulated or goes out of whack.
The most common error codes:
- E1 — Temperature sensor malfunction (open circuit). The compressor may not turn on or operate constantly in emergency mode.
- E2 — Temperature sensor malfunction (short circuit). Often indicates damage to the wire or moisture ingress into the connector.
- E3 — Defrost sensor error (valid for No Frost models).
- AL or Hi — High temperature alarm. Lights up if the temperature in the chamber has exceeded the permissible threshold for a long time.
When the code appears E1 or E2 automatic temperature adjustment becomes impossible. The controller switches to operation according to the emergency algorithm (usually cyclic on/off). In this case, it is necessary to check the integrity of the sensor wire going from the board to the evaporator. Often the wire is broken at the point where it exits the housing or in the door hinge.
Typical problems and methods for eliminating them
Even with the correct settings, users may encounter a situation where the actual temperature does not correspond to the set one. One common cause is improper placement of products. If the flow of cold air from the evaporator to the sensor is blocked, the controller “thinks” that it is warm in the chamber and runs the compressor without interruption, freezing the food at the back wall.
Another problem is a loose fit of the door seal. Professional cabinets Polair use magnetic seals, which can weaken or become dirty over time. The constant influx of warm, humid air causes the system to wear out. You can check the seal using a sheet of paper: hold it with the door and try to pull it out. If the sheet comes out freely anywhere along the perimeter, the seal requires adjustment or replacement.
It is also worth mentioning the influence of the external environment. If the refrigerator is placed in direct sunlight or next to a heat source (stove, radiator), the standard power may not be enough to achieve the set temperature. In such cases, even the correct settings of the controller will not help - it is necessary to eliminate the external ventilation or improve the ventilation around the condenser.
If the temperature stabilizes, but after a while it starts to “float” again, check the operation of the cooling fans. In models Polair with forced circulation, stopping the fan leads to local overcooling of the evaporator and overheating of the rest of the chamber, which disrupts the controller algorithms.
Frequently asked questions (FAQ)
How to reset the Polair controller settings to factory settings?
To reset the settings to factory values (Factory Reset), you usually need to enter the programming menu, find the parameter rS (Reset) and set the value YES or 1. However, the exact combination depends on the controller model. Often it helps to simultaneously press the “Up” and “Down” buttons when the power is off, but this does not work on all firmware versions.
Why does the Polair refrigerator not keep the temperature -18°C?
There may be several reasons: refrigerant leak, thermostat malfunction, compressor wear, or simple contamination of the condenser dust. First, check the cleanliness of the radiator at the back or bottom of the cabinet. If the radiator is clean and the compressor operates continuously without reaching temperature, most likely the system needs to be refilled with freon or repaired.
Is it possible to use an external thermostat instead of the built-in one?
Technically this is possible, but not recommended for professional equipment. The built-in controller Polair controls not only the compressor, but also fans, defrost and alarm. Connecting an external relay will disrupt the logic of the defrost system, which will lead to ice fouling on the evaporator and eventual breakdown.
How often should you check the calibration of the sensors?
It is recommended to compare the controller readings with a reference thermometer at least once every six months. For catering and retail establishments, this requirement is often regulated by sanitary standards. Regular checking will allow you to notice in time the “drift” of the sensor readings.