1-Electric control system installation technology
1. Each contact is marked with a wire number for easy maintenance.
2. Make the electric control box in strict accordance with the requirements of the drawings, and connect the electricity to do the no-load test.
4. Fix the wires of each electrical component with binding wires.
5. The electrical contacts should be pressed tightly on the wire connectors, and the motor main wire connectors should be clamped tightly with wire clips, and tinned if necessary.
6. Pipelines should be laid for the connection of each equipment and fixed with clips. PVC pipes should be glued when connected, and the mouth of the pipes should be sealed with tape.
7. The distribution box is installed horizontally and vertically, the ambient lighting is good, and the house is dry for easy observation and operation.
8. The area occupied by wires and wires in the pipe shall not exceed 50%.
9. The selection of wires must have a safety factor, and the temperature of the wire surface must not exceed 4 degrees when the unit is running or defrosting.
10. The three-phase electricity should be 5-wire system, and the ground wire should be installed if there is no ground wire.
11. The wires should not be exposed to the open air, so as to avoid long-term exposure to the sun and wind, aging of the wire skin, short circuit leakage and other phenomena.
12. The installation of the line pipe should be beautiful and firm.
2-Refrigeration system plus refrigerant debugging technology
1. Measure the power supply voltage.
2. Measure the three winding resistances of the compressor and the insulation of the motor.
3. Check the opening and closing of each valve of the refrigeration system.
4. After evacuating, fill the refrigerant into the storage liquid to 70%-80% of the standard charging volume, and then run the compressor to add gas from low pressure to enough volume.
5. After turning on the machine, first listen to the sound of the compressor to see if it is normal, to see if the condenser and air cooler are running normally, and if the three-phase current of the compressor is stable.
6. After normal cooling, check each part of the refrigeration system, exhaust pressure, suction pressure, exhaust temperature, suction temperature, motor temperature, crankcase temperature, and temperature before the expansion valve Observe the frosting of the evaporator and expansion valve, observe the oil level and color change of the oil mirror, and check whether the sound of the equipment is abnormal.
7. Set the temperature parameters and the opening degree of the expansion valve according to the frosting and usage of the cold storage.
3-Blowdown of the refrigeration system
1.The interior of the refrigeration system must be very clean, otherwise the garbage remaining in the system will block the orifice, lubricating oil passage, or roughen the friction surfaces.
Leak detection of refrigeration system:
2.Pressure leak detection is the most effective method. The leak detection pressure in the system is related to the type of refrigerant used, the cooling method of the refrigeration system and the position of the pipe section. For high pressure systems, the leak detection pressure
3.The pressure is about 1.25 times the design condensing pressure; the leak detection pressure of the low-pressure system should be approximately 1.2 times the saturation pressure at ambient temperature in summer
4-refrigeration system debugging
1. Check whether each valve in the refrigeration system is in the normal open state, especially the exhaust stop valve, do not close it.
2. Open the cooling water valve of the condenser. If it is an air-cooled condenser, turn on the fan and check the direction of rotation. The water volume and air volume should meet the requirements.
3. The electrical control circuit should be tested separately in advance, and the power supply voltage should be normal before starting.
4. Whether the oil level of the crankcase of the compressor is in the normal position, generally it should be kept at the horizontal center line of the oil sight glass.
5. Start the refrigeration compressor and check whether it is normal. Whether the rotation direction of the compressor is correct.
6. After the compressor is started, check the indication values of the high and low pressure gauges to see if they are within the pressure range for the normal operation of the compressor, and check the indication values of the oil pressure gauge.
7. Listen to the expansion valve for the sound of refrigerant flowing, and observe whether there is normal condensation and frosting in the pipeline behind the expansion valve. In the initial stage of operation, it should work at full load, which can be rooted in ，According to the temperature of the cylinder head by hand.
Post time: Apr-03-2023