Midea MOU-55FN8-RD0 - Note on Adding Refrigerant

 Page 28 
Air Evacuation
Note On Adding Refrigerant
CAUTION
• Refrigerant charging must be performed after wiring, vacuuming and the leak test.
• DO NOT exceed the maximum allowable quantity of refrigerant or overcharge the system.
Doing so can damage or impact the unit’s function.
• Charging with unsuitable substances may cause explosions or accidents. Ensure that the
appropriate refrigerant is used.
• Refrigerant containers must be opened slowly. Always use protective gear when charging the
system.
• For the R290 or R32 refrigerant model, make sure the condtions within the area have been
made safe by control of ammable material when the refrigerant added into air conditioner.
• The maximum refrigerant charge amount of R32 is 305 grams.
• DO NOT mix refrigerants types.
Some systems require additional charging depending on pipe lengths. The standard pipe length
varies according to local regulations. For example, in North America, the standard pipe length is
7.5m (25’) In other areas, the standard pipe length is 5m (16‘). The additional refrigerant to be
charged can be calculated using the following formula:
Liquid Side Diameter
R32 :
(Total pipe length -
standard pipe length)x
12g(0.13oZ)/m(ft)
(Total pipe length -
standard pipe length)x
24g(0.26oZ)/m(ft)
(Total pipe length -
standard pipe length)x
40g(0.42oZ)/m(ft)
φ6.35(1/4”) φ9.52(3/8”) φ12.7(1/2”)
R22
(orifice tube in the indoor unit):
(Total pipe length -
standard pipe length)x
30g (0.32oZ)/m(ft)
(Total pipe length -
standard pipe length)x
65g(0.69oZ)/m(ft)
(Total pipe length -
standard pipe length)x
115g(1.23oZ)/m(ft)
R22
(orifice tube in the outdoor unit):
(Total pipe length -
standard pipe length)
x15g(0.16oZ)/m(ft)
(Total pipe length -
standard pipe length)
x30(0.32oZ)/m(ft)
(Total pipe length -
standard pipe length)
x60g(0.64oZ)/m(ft)
(Total pipe length -
standard pipe length)
x65g(0.69oZ)/m(ft)
R410A:
(orifice tube in the indoor unit):
(Total pipe length -
standard pipe length)
x30g(0.32oZ)/m(ft)
(Total pipe length -
standard pipe length)
x65g(0.69oZ)/m(ft)
(Total pipe length -
standard pipe length)
x115g(1.23oZ)/m(ft)
R410A:
(orifice tube in the outdoor unit):
(Total pipe length -
standard pipe length)
x15g(0.16oZ)/m(ft)
(Total pipe length -
standard pipe length)
x30g(0.32oZ)/m(ft)