warning protection
Personal protective equipment such as gloves, glasses, shoes should be provided when operating this equipment.
Installation, commissioning, testing, shutdown and maintenance services should be performed by qualified personnel (refrigeration mechanics or electricians) with sufficient knowledge and experience of this type of equipment. It is the customer’s responsibility to provide operational personnel to carry out the work.
All equipment may be charged with high pressure dry air or nitrogen. Be sure to discharge the compressed gas carefully before installation or commissioning of the equipment.
Avoid touching the edges of the sheet metal and the fins of the coil, as sharp edges may cause personal injury.
Inhalation or skin contact with refrigerant can cause injury, the refrigerant used in this equipment is a controlled substance and must be used and recycled responsibly. It is illegal to discharge refrigerant into the surrounding environment. Handle the refrigerant very carefully, otherwise, personal injury or death may occur.
Power must be disconnected prior to any service or electrical work.
Avoid contact with refrigerant piping and heat exchange surfaces when the equipment is in operation. Hot or cold surfaces can cause damage to your skin.
Standard Design Conditions
The medium temperature evaporator is designed with a saturated suction temperature of 0°C and a temperature difference of 8K. It is suitable for commercial refrigerators with room temperature ranging from -6°C to 20°C. Additional defrosting methods are required when the room temperature is below 2°C. The recommended refrigerants for this evaporator are R507/R404A and R22.
The low temperature evaporator is designed with a saturated suction temperature of -25°C and a temperature difference of 7K. It is suitable for commercial cold storage with room temperature ranging from -6°C to -32°C. The recommended refrigerants for this evaporator are R507/R404A and R22.
These standard evaporators cannot use ammonia ( NH 3 ) as a refrigerant.
Recommended installation location
Evaporator arrangement rules are as follows:
Air distribution should cover the entire room or effective area.
It is forbidden to install the evaporator on the top of the door.
The arrangement of the aisles and shelves should not obstruct the flow passages of the supply air and return air of the evaporator.
The piping distance from the evaporator to the compressor should be kept as short as possible.
Keep the pipe distance to the drain as short as possible.
Minimum allowable mounting clearance:
S1 – The distance between the wall and the air side of the coil is at least 500mm.
S2 – For ease of maintenance, the distance from the wall to the end plate shall be at least 400mm.
Installation Notes
1. Removal of packaging:
When unpacking, inspect the equipment and packing materials for damage, any damage may affect operation. If there are obvious damaged parts, please contact the supplier in time.
2. Equipment installation:
These evaporators can be secured with bolts and nuts. In general, a single 5/16 bolt and nut can hold up to 110Kg (250lb) and a 3/8 can hold up to 270Kg (600lb). Having said that, it is the installer’s responsibility to ensure that the evaporator is installed safely and professionally in the designated location.
Bolt the evaporator and leave enough space from the top plate to the ceiling for easy cleaning.
Mount the evaporator in alignment on the ceiling, and seal the gap between the ceiling and the top of the evaporator with food sealant.
The installation of the evaporator should be professional and the location should be appropriate to ensure that the condensed water can be effectively discharged from the evaporator. The support must have sufficient capacity to bear the weight of the evaporator itself, the weight of the refrigerant charged and the weight of the frost lodged on the surface of the coil. If possible, it is recommended to use a lifting device to lift the ceiling.
3. Drain pipe:
Please confirm that the installation of the drain pipe conforms to the HACCP of food and the corresponding safety regulations. The material can be copper pipe, stainless steel pipe or PVC pipe, according to the customer. For low temperature applications, insulation and heating wires are required to prevent the drain pipe from freezing. It is recommended to install drain pipes correctly every 1m of 300mm slope. The drain pipe is at least the same size as the evaporator sump pan connection. All condensate drainage pipes must be installed with U-shaped bends to prevent outside air and odors from entering the cold storage. It is absolutely forbidden to directly connect with the sewage system. All U-bends are placed outdoors to prevent icing. It is recommended that the length of the drain pipe in the cold storage be as short as possible.
4. Refrigerant separator and nozzle:
In order to ensure the best cooling effect of the evaporator, the liquid separator must be installed vertically to ensure that the refrigerant is evenly distributed to each refrigeration circuit.
5. Thermal expansion valve, temperature sensing package and external balance pipe:
In order to achieve the best cooling effect, the thermal expansion valve should be installed as close to the liquid separator as possible.
Place the thermal expansion valve bulb in the horizontal position of the suction pipe and close to the suction header. In order to achieve a satisfactory operating state, it is necessary to ensure good thermal contact between the bulb and the suction pipe. The placement of the thermal expansion valve and temperature bulb should follow the manufacturer’s instructions. Improper installation can result in poor cooling.
The external balance pipe is used to connect the external balance port of the thermal expansion valve and the suction pipe near the suction pipe. The 1/4 inch copper pipe that connects to the suction pipe is called the outer balance pipe.
Note: At present, the quality of the thermal expansion valve is relatively good, there is little refrigerant leakage on the external balance pipe, and the operation is relatively stable. Accordingly, the connection position of the external balance can be either in front of the temperature sensor or behind the temperature sensor.
6. Refrigeration pipeline:
The design and installation of refrigeration pipelines must be performed by qualified refrigeration mechanics in accordance with national and local regulations, and in accordance with good refrigeration engineering operation practices.
During installation, minimize the time the nozzle is exposed to the air to prevent the entry of external impurities and moisture.
The refrigeration connecting pipeline does not have to be the same as the outlet pipeline of the evaporator. The selection and calculation of the pipeline size should be based on the principle of minimum pressure drop and flow velocity attenuation.
The horizontal suction pipe needs to leave the evaporator with a certain inclination to ensure that the gravity of the frozen oil wipes returns to the compressor. A slope of 1:100 is sufficient. When the suction pipe is higher than the evaporator, it is better to install the oil return trap.
Debugging guide
The start-up and commissioning of the refrigeration system should be performed by a qualified refrigeration mechanic in accordance with the correct refrigeration operation practice.
The system must maintain a sufficient vacuum so that there are no leaks when charging the refrigerant. If there is a leak in the system, it is felt that recharging the refrigerant is not allowed. If the system is not under vacuum, check for leaks with nitrogen under pressure before charging the refrigerant.
It is a good engineering application to install liquid dryer and sight glass in refrigeration system. Liquid line dryers ensure that the refrigerant in the system is clean and dry. The sight glass is used to check that there is sufficient refrigerant in the system.
Charging is performed with a liquid refrigerant, typically on the high-pressure side of the system, such as a condenser or accumulator. If charging must be done on the suction side of the compressor, it must be charged in gaseous form.
The factory wiring may be loose due to transportation, please reconfirm the wiring before leaving the factory and the wiring on site. Check that the fan motor is running in the correct direction and that the airflow is drawn in from the coil and discharged from the fan side.
Shutdown Guide
Remove the evaporator from its original installation location and must be dismantled by a qualified refrigeration mechanic following the procedure below. Failure to follow this procedure will result in operator injury or death and property damage due to fire or explosion. It is illegal to discharge the refrigerant directly into the atmosphere. The fully charged refrigerant should be pumped to the accumulator or suitable liquid storage tank, such as a recycling cylinder, and the corresponding valve should be closed at the same time. All recovered refrigerants that cannot be reused must be sent to qualified refrigerant reuse or destruction places.
Cut off the power supply. Remove all unnecessary field wiring, corresponding electrical components, and finally cut the ground wire and disconnect the drain.
In order to balance the pressure between the evaporator and the outside world, special care must be taken when opening the needle valve core. A certain amount of refrigerant is dissolved in the lubricating oil. When the pressure of the evaporator rises, the refrigerant will boil and volatilize, which may cause personal injury.
Cut off and seal the joints of the liquid and gas lines.
Remove the evaporator from the installation location. When required, use lifting equipment.
routine maintenance
Based on normal operating conditions and environment, after successful commissioning, a maintenance schedule should be prepared to ensure that the evaporator operates at optimum efficiency while keeping operating costs at a minimum. When doing maintenance, check and record the following parameters:
Check the evaporator for corrosion, abnormal vibration, oil plugs and dirty drains. Drains require frequent cleaning with warm soapy water.
Clean the evaporator fins with a soft brush, rinse the coils with low pressure light water or use a commercially available coil washer. The use of acidic cleaning agents is prohibited. Please follow the logo’s usage guidelines. Flush the coil until there is no residue.
Check that each motor fan rotates correctly, that the fan cover is not blocked, and that the bolts are tightened.
Check wires, connectors, and other components for wire damage, loose wiring, and wear on components.
Check for uniform frost formation on the exhaust side coil during operation. Uneven boxing indicates a blockage in the dispenser head or an incorrect refrigerant charge. There may be no frost on the coil at the suction place because of the superheated gas.
Look for abnormal frost conditions and adjust the defrost cycle accordingly.
Check the superheat and adjust the thermal expansion valve accordingly.
Power must be turned off during cleaning and maintenance. Drain pans are also parts that need servicing (hot, cold, electrical and moving parts). There is a safety hazard in the operation of the evaporator without a water sump.
Post time: Nov-23-2022
