Hitachi RAS-(4-12)HNP(1)(E) - Additional Refrigerant Charge Calculation for Indoor Unit; Calculation of Total Additional Refrigerant Charge; Charging Work; Total Refrigerant Charge of the System

3 Piping work and
refrigerant charge
87
SMGB0087 rev.0 - 12/2013
3
Step 2: Additional refrigerant charge calculation for indoor unit (W
2
(kg))
When the outdoor unit is combined with indoor units RPI-(8/10)HP allowed (1 unit system combination only), it´s necessary
an additional refrigerant charge (W
2
) = 1kg/unit. For indoor units lower than 8 HP, an additional refrigerant charge it’s not
needed.
Indoorunitcapacity Additionalrefrigerantcharge(W
2
(kg))
≥ 8 HP 1
< 8 HP 0
Step 3: Calculation of total additional refrigerant charge (W (kg))
a. For all UTOPIA units except RAS-(8-12)HN(P/C)(E)
Put weight W
1
and W
2
calculated in step 1 and step 2 into the following formula:
W=W
1
+W
2
System example (W) = + = kg
b. For UTOPIA units RAS-(8-12)HN(P/C)(E)
In case of RAS-(8-12)HN(P/C)(E), it must be used the following formula:
W=W
1
+W
2
-C
System example (W) = + – = kg
C: Compensation value (kg) (Refer to the following table)
Model Compensationvalue(C(kg))
RAS-8HN(P/C)E 1.6
RAS-10HN(P/C)E 2.0
RAS-12HN(P/C) 2.0
 C A U T I O N
Donotexceedtheallowedmaximumadditionalcharge
Step 4: Charging work
Charge refrigerant (R410A) into the system according to the instructions in the Service Manual.
Step 5: Total refrigerant charge of the system (W
TOT
(kg))
The total refrigerant charge of this system is calculated by the following formula:
W
TOT
=W+W
0
System example (W
TOT
) = + = kg
W
0
is the outdoor unit refrigerant charge before shipment previous explained, and it’s shown in its specic table.
Finally, record the refrigerant charge quantity in order to facilitate maintenance and servicing activities.
Total additional charge W
kg
kg
Total ref. charge of this system
Date of ref. charge work
Year
Month
Day