How to inject refrigerant into the air conditioning system?
Refrigerant injection principle: The refrigerant is pressed into the system by the pressure difference between the refrigerant and the system.
A. Detect the air conditioning system, vacuum for 30 minutes, and reach the negative pressure state (-0.1MPA).
B. Add a part of gaseous refrigerant from the low pressure port into the system. After the cylinder pressure and system pressure are basically balanced, turn on the cooling state. When filling the low pressure 0.4MPA, observe the cooling effect.
Different refrigerants have different pressure requirements during the test run:
R22: low pressure is 0.4-0.6MPA; high pressure is less than 2.2MPA;
R410: low pressure is 0.7-0.9MPA; high pressure is less than 3.5MPA;
R32: Low pressure is 0.7-1MPA; high pressure is less than 3.5MPA
R290: Low pressure is 0.4-0.55MPA, high pressure is 2MPA.
C air conditioning trial run cooling for about 30 minutes, carry out careful testing, including measuring pressure, listening to sound, measuring temperature, measuring working current and so on.