DC Inverter Multi VRF System
17
Quantity of additional refrigerant = ∑length of liquid pipe
× quantity of additional refrigerant per
meter.
Quantity of additional refrigerant per meter for liquid pipe(kg/m)
Pipe size(mm)
Φ22.2
Φ19.05
Φ15.9
Φ12.7
Φ9.52
Φ6.35
Quantity of
additional
refrigerant(kg)
0.35
0.25
0.17
0.11
0.054
0.022
First confirm that there is no leakage from the system. When compressor is not working, charge
additional R410A with specific amount to the unit through the filling opening of the liquid pipe valve of the
outdoor unit. If required amount cannot be quickly filled due to pressure increase of the pipe, then set the
unit in cooling startup and fill refrigerant from the low pressure check valve of the outdoor unit.
(3) Calculation example.
Fig.4.21
IDU:
No.
IDU
①
IDU
②
IDU
③
IDU
④
Model
Duct type
GMV-ND71PL/B-T
Duct type
GMV-ND50PL/B-T
Duct type
GMV-ND36PL/B-T
Duct type
GMV-ND25PL/B-T
Liquid pipe:
No.
A
B
C
D
Pipe size(mm)
Φ
9.52
Φ
9.52
Φ
9.52
Φ
6.35
Length(m)
10
5
5
5
No.
a
b
c
d
Pipe size(mm)
Φ
9.52
Φ
6.35
Φ
6.35
Φ
6.35
Length(m)
3
3
2
1
(4) Total length of each liquid pipe.
Φ
9.52: A+B+C+a=10+5+5+3=23m
Φ
6.35: D+b+c+d=5+3+2+1=11m
Therefore, the minimum quantity of additional refrigerant = 23×0.054+11×0.022=1.484kg
4.5 Electric Wiring
4.5.1 Notices for Wiring
(1) Install units according to national wiring codes.
(2) Use air conditioner specialized power supply and make sure that it is consistent with
system’s rated voltage.
(3) Do not pull the power cord with force.
