Introduction to a 25 horsepower explosion-proof refrigeration and heating dual-purpose electronic expansion valve unit

      Introduction to a 25 horsepower explosion-proof refrigeration and heating dual-purpose electronic expansion valve unit

   This unit is used for both cooling and heating purposes. The system integrates external and internal units, expansion valves, control boxes, and refrigerants, ensuring stability and reliability. Remote monitoring is optional. The key electronic expansion valve control program adopts PID fuzzy logic control, which automatically adjusts the opening of the electronic expansion valve to help the refrigeration system operate energy-efficient

The internal unit adopts an explosion-proof motor, which can be used for heating and hot fluorine defrosting

When installing the device, please follow the following installation process.

1. Install the unit and the air cooler in place, connect the inner and outer copper pipes with insulation pipes (both copper pipes must be covered with insulation pipes),

2. Lead the main power line 3 * 10+2 * 6 wires to the outer machine wiring column. The inner machine takes power from the outer machine (supplying power to the air cooler motor): Take power from the wiring column of the outer machine control box. If the motor is 380V, match the 25 horsepower air cooler, and use 3 * 2.5 wires+2 * 1.5 grounding wires and zero wires for the fan wire

3. Lead the temperature probe and inner coil probe into the cold storage, with a standard 15 meter wire installed at the factory. The temperature probe is placed 500mm away from the side of the air cooler, fixed with a hard auxiliary wire, with the probe facing upwards and the lead wire below, as shown in the figure. The inner coil probe can be inserted into the lower fins behind the air cooler.

4. The operation panel is equipped with an explosion-proof junction box, which can be installed next to the cold storage door or at any convenient location for operation. Factory standard connection line of 20 meters (which is a typical telephone line)

5. After connecting the copper pipes of the internal and external units (checking the joints to ensure there are no leakage points), it is necessary to maintain pressure and vacuum the valve section from the internal unit to the external unit. At this time, do not open the valve of the external unit. At the needle valve of the suction pipe of the cold air fan, draw a vacuum for more than half an hour. Then, open two external unit valves (because the external unit has been debugged and filled with Freon before leaving the factory), and let the Freon inside the external unit fill the entire refrigeration system. Preparation work completed.

6. Close the air switch inside the external unit to start the machine. Three conditions must be met when starting up

A. If the refrigeration mode is selected, the storage temperature should be higher than the set temperature by ten loading temperature differences

If the heating mode is selected, the temperature of the warehouse should be lower than the set temperature. Once loaded, the temperature should be low

Special attention, please do not switch to cooling mode or heating mode in a short period of time, as this will cause oil spray from the semi enclosed compressor and trigger an oil pressure difference alarm. If automatic cooling and heating mode is selected, the temperature of the warehouse will be higher than the set temperature plus the cooling temperature difference (factory setting of 5 degrees), and the duration will exceed 4 minutes. The unit will automatically operate in cooling mode. If the temperature of the warehouse is lower than the set temperature minus the temperature difference of the conversion heat (factory set at 2 degrees) and lasts for more than 4 minutes, the unit will automatically operate in heating mode. When setting this mode, the switching time should be as long as possible, because too short a switching time can cause the compressor to spray oil and cause an oil pressure difference alarm. If it is not necessary, try not to choose this mode.

B. There is a minimum delay time setting for startup,

C, the control circuit is connected, and there is no alarm

7. Shutdown conditions

A. When the temperature of the cold storage reaches the set temperature during refrigeration, it will shut down.
When heating, when the temperature of the cold storage reaches the set temperature in automatic mode, the heating shutdown temperature is the set temperature ten revolutions cooling temperature difference, and the cooling shutdown temperature is the set temperature ten revolutions heating shutdown temperature difference

B. If there is a fault alarm, it will also shut down.

8. Start defrosting conditions

A. When the machine running time exceeds the minimum defrosting time interval, it will automatically defrost with hot fluorine. The minimum defrosting time interval refers to the compressor running time when the evaporation temperature is below 2 degrees Celsius, and the timing of this time will be displayed on the panel

When the temperature difference exceeds 6 degrees, temperature difference defrosting will be activated. When the time interval is set for a long time, defrosting with frost and no frost will be achieved.

B. In the user settings, when setting manual defrosting, hot fluorine defrosting will also start.

During heating, the external unit defrosts: it must meet four conditions at the same time, with an ambient temperature of<12 degrees Celsius, and the external unit defrosts

9. Conditions for ending defrosting

A. When the defrosting time is up, it will stop defrosting

B. Defrosting will stop when the temperature reaches, whichever comes first.