Hitachi RAS-2HVNP Installations- Und Betriebshandbuch Seite 28

14
1 Refrigerant piping & refrigerant charge
14.6 REFRIGERANT CHARGING QUANTITY
In case of the actual piping length is more than the specified length, the additional refrigerant quantity should be charged according
to the table below:
RAS-2HVNP
RAS-2.5HVNP
RAS-3HVNC
RAS-3HVRNS3
1 Determine an additional refrigerant quantity according to the following procedure, and charge it into the system.
2 Record the additional refrigerant quantity to facilitate service activities thereafter.
C A U T I O N
• When charging refrigerant accurately measure refrigerant to be charged.
• Overcharging or undercharging of refrigerant can cause compressor trouble.
• In case of actual piping length less than 5 m, consult your distributor.

Additional refrigerant quantity calculation
Calculate piping length L(m)
Outdoor unit
Example:
Outdoor unit
RAS-2HVNP

Setting of Pipe Length DSW.
DSW2 setting will be required only when the refrigerant pipe leng-
th is shorter than 5 m or longer than 30 m. Pipe length setting
shall be performed as shown below.

(The side in the table below shows the DSW location)
DSW2 on Outdoor PCB1
Factory setting Pipe Length ≤ 5m
28
Chargeless length (m)
Outdoor unit refri-
gerant charge (kg)
1 IU
1.6 30
1.6 30
1.9 20
1.9 20
Indoor unit
L = 50 L: 50 m
: 30 m
l
P: 0.03
Indoor unit
Pipe Length ≥ 30m
PMML0248A
Additional refrigerant charge (P)
(kg/m)
2 IU 1 IU
0 0.03
0 0.03
20 0.04
0.04
-
L: Piping Length
: Chargeless length
l
P: Additional refrigerant charge
(a): No additional charge is required: L≤
(b): Additional charge is required: L≥
W (additional charge quantity) = (L-
W (additional charge quantity) = (50-30) x 0.03 = 0.6 kg
Max additional
charge (kg)
2 IU
0.03 1.5
0.024 1.2
0.04 1.2
1.2
-
l
l
) x P
l