Gree GWHD(28)NK3FO - Page 47

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Installation and Maintenance
Service Manual
4) Make sure the system has no leakage. When compressor is not working, fill a set amount of R410a refrigerant into the unit
through outdoor unit’s liquid valve. If the inner tube pressure rises and the set amount of refrigerant can’t be filled inside quickly,
you can turn on the unit to make it start cooling, then fill the refrigerant inside through outdoor unit’s gas valve.
a.
Calculation of the Additional Refrigerant Charging
1) Refrigerant Charge in the Outdoor Unit before Shipment
Table 6
Model GWHD(42NK3AO
Refrigerant Charge (kg)
GWHD(36)NK3BO
4.24.8
Notes
˖
ķ
The refrigerant charge mentioned in the table above is not included those charged additionally in the indoor unit and the
refrigerant pipe.
ĸ
The amount of the additional refrigerant charge is dependent on the diameter and length of the liquid refrigerant pipe
which is decided by the actual yield installation requirement.
Ĺ
Record the additional refrigerant charge for future maintenance.
2) Calculation of the Additional Refrigerant Charge
If the total refrigerant pipe length (liquid pipe) is smaller than that listed in the table below, no additional refrigerant will be
charged.
Table 7
Model Total Liquid Pipe Length (a+b+c+d+e)
GWHD(36)NK3BO ≤40m
GWHD(42)NK3AO ≤50m
Additional Refrigerant Charge2=∑Extra Liquid Pipe Length×22g/m(liquid pipe 1/4").
Note: if the total refrigerant pipe length is larger than that listed in the table above, the additional refrigerant for the extra
length of the pipe needs to be charged as per 22g/m.
3) Example : GWHD (42) NK3AO
Fig.9
Table 8 Indoor Unit
Serial No. Model
Indoor Unit
Ļ
Ducted Type GFH(09)EA-K3DNA1A/I
Indoor Unit
ĺ
Ducted Type GFH(09)EA-K3DNA1A/I
Indoor Unit
Ĺ
Ducted Type GFH(09)EA-K3DNA1A/I
Indoor Unit
ĸ
Ducted Type GFH(09)EA-K3DNA1A/I
Indoor Unit

Ducted Type GFH(18)EA-K3DNA1A/I
Table 9 Liquid Refrigerant Pipe
Serial No. e dcba
Diameter Φ6.35 Φ6.35 Φ6.35Φ6.35 Φ9.52
Length 20m 20m 15m 5m 5m
The total length of each liquid refrigerant pipe is: e+d+c+b+a=20+20+15+5+5=65m. Thus, the minimum additional
refrigerant charge=(65-50)×0.022=0.33kg (Note: no additional refrigerant is needed for the liquid pipe within 50m).
a
b
c
d
e