7
GB-21
 
8.4 Note On Adding Refrigerant
Note: 1) Please use tools for R410A/R32 system respectively;
            2) The standard pipe length is 7.5m (24.6’). When the pipe length is over 7.5m, the additional 
                  refrigerant should be added according to the piping length.
8.5 Safety And Leakage Check
 CAUTION
•  Refrigerant charging must be performed after wiring, vacuuming, and the leak testing.
• 
DO NOT exceed the maximum allowable quantity of refrigerant or overcharge the system. 
Doing so can damage the unit or impact it’s functioning.
• 
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.
•   
• 
DO NOT mix refrigerants types. 
N=2(one-twin models), N=3(one-three models), N=4(one-four models), N=5(one-five models).Depending on the length
of connective piping or the pressure of the evacuated system, you made need to add refrigerant. Refer to table
below for refrigerant amounts to be added:
ADDITIONAL REFRIGERANT PER PIPE LENGTH
Connective Pipe 
Length 
Air Purging 
Method
Additional Refrigerant  
        (
R410A/R32)
Pre-charge pipe length(ft/m)
(Standard pipe lengthxN)
Vacuum Pump
N/A
             More than 
(Standard pipe lengthxN)ft/m
Vacuum Pump
Liquid Side: Ø 6.35 (Ø 1/4”)
(Total pipe length - standard pipe lengthxN) x15g/m  /
(Total pipe length - standard pipe lengthxN) x12g/m
Liquid Side: Ø 9.52 (Ø 3/8”)
(Total pipe length - standard pipe lengthxN) x30g/m  / 
(Total pipe length - standard pipe lengthxN) x24g/m
Electrical safety check
Perform the electrical safety check after 
completing installation. Cover the following areas:
1.  Insulated resistance
     The insulated resistance must be more than 2MΩ.
2.  Grounding work 
 After finishing grounding work, measure the grounding
    resistance by visual detection and using the grounding
    resistance tester. 
    Make sure the grounding resistance is less than 4Ω. 
3. Electrical leakage check (performing during test while
    unit is on)
    During a test operation after completed installation, 
    use the electroprobe and multimeter to perform an
    electrical leakage check. Turn off the unit immediately
    if leakage happens. Try and evaluate different solutions
   until the unit operates properly.
Gas leak check
1.  Soap water method:
 Apply a soap-water solution or a liquid neutral detergent
     on the indoor unit connection or outdoor unit connections 
     with a soft brush to check for leakage of the connecting
     points of the piping. If bubbles emerge, the pipes are 
     experiencing leakage.
2.  Leak detector
     Use the leak detector to check for leakage.
NOTE: The illustration is for example purposes 
only. The actual order of A, B, C, D, and E on the 
machine may be slightly different from the unit 
you purchased but the general shape will remain 
the same.
 
 
Indoor unit 
check point
Outdoor unit 
check point
A, B,C,D are points for the one-four type.
A, B,C,D, and E are points for the one-five type.
Fig. 8.4
8. AIR EVACUATION