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Note on Adding Refrigerant
Safety And Leakage Check
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 may 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.
•
•
DO NOT
mix refrigerant types.
N=2 (one-twin models), N=3 (one-three models), N=4 (one-four models), N=5 (one-five models).
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 7.5 m (25 ft)
In other areas, the standard pipe length is 5 m (16 ft). The additional refrigerant to be charged can be
calculated using the following formula:
Air
Evacuation
ADDITIONAL REFRIGERANT PER PIPE LENGTH
Connective Pipe
Length
Air Purging
Method
Additional Refrigerant (
R410A:)
Pre-charge pipe length (ft/m)
(standard pipe length x N)
Vacuum pump
N/A
More than (standard
pipe length x N) ft/m
Vacuum pump
Liquid Side: Ø 6.35 (Ø 1/4”)
(Total pipe length - standard pipe length x N) x 15 g/m
(Total pipe length - standard pipe length x N) x 0.16 oZ/ft
Liquid Side: Ø 9.52 (Ø 3/8”)
(Total pipe length - standard pipe length x N) x 30 g/m
(Total pipe length - standard pipe length x N) x 0.32 oZ/ft
Electrical safety check
Perform the electric safety check after
completing installation:
1. Insulated resistance
The insulated resistance must be more
than 2 M
Ω
.
2. Grounding work
After finishing the grounding work, measure
the grounding resistance by visual detection
and with a grounding resistance tester. Make
sure the grounding resistance is less than 4
Ω
.
3. Electrical leakage check (performed during
test running)
During test operation after installation is
finished, the service man can use the
electroprobe and multimeter to perform
the electrical leakage check. Turn off the
unit immediately if there is leakage.
Look for a solution to the problem until
the unit operates properly.
Gas leak check
1. Soapy water method:
To check for leakage in the connecting points
of the piping, use a soft brush to apply soapy
water or a liquid neutral detergent to the
indoor or outdoor unit connections. If bubbles
come out, there is leakage.
2. Leak detector
Use the leak detector to check for leakage.
NOTE:
The illustration is for explanation purposes
only. The actual order of A, B, C, D and E on the
machine may be slightly different from the unit
you purchased. The actual shape shape prevails.
Indoor unit
check point
Outdoor unit
check point
A, B, C, and D are points on a one-four type.
A, B, C, D, and E are points on a one-five type.
Fig. 9.4
