Hitachi RASC-4HNPE Service Manual page 59

3 Piping work and refrigerant charge
Refrigerant charge
Step 2: Additional refrigerant charge calculation for indoor unit (W
When the RASC unit is combined with indoor units RPI-(8/10)HP, an additional refrigerant charge is required (W
unit. For indoor units lower than 8 HP, an additional refrigerant charge is not needed.
Step 3: Calculation of total additional refrigerant charge (W (kg))
For RASC-(4-6)HNPE units
Put weight W and W calculated in step 1 and step 2 into the following formula:
1 2
For RASC-(8/10)HNPE units
In case of RASC-(8/10)HNPE units, the following formula must be used:
C: Compensation value (kg) (Refer to the following table)
!
C A U T I O N
Do not exceed the allowed maximum additional charge.
Step 4: Total refrigerant charge of the system (W
The total refrigerant charge of this system is calculated by the following formula:
Finally, record the refrigerant charge quantity in the F-Gas label in order to facilitate maintenance and servicing activities.
49 SMGB0091 rev.2 - 11/2015
Indoor unit capacity
≥ 8 HP
< 8 HP
W = W
System example (W) =
W = W
System example (W) =
Model
RASC-8HNPE
RASC-10HNPE
W
TOT
System example (W ) =
TOT
(kg))
2
Additional refrigerant charge
(W (kg))
2
1
0
+ W
1 2
+ =
+ W - C
1 2
+ – =
Compensation value (C (kg))
1.6
2.0
(kg))
TOT
= W + W
0
+ =
W
0
W -W
TOT
W
TOT
) = 1 kg/
2
kg
kg
kg
0
3