Hitachi HRNM Série Manuel D'installation page 39

1. Calculating Method of Additional Refrigerant Charge W (kg)
Calculate the additional refrigerant charge amount according to the following method:
Example:
1.1. Additional Refrigerant Charge Calculation for Liquid Piping (W
Calculate the additional refrigerant charge amount for liquid piping as below and see example for model RAS-10HRNM,
and fill in the following table.
Example:
Piper Diameter Total Pipe
(mm) Length (m)
12.7 10
9.53 5+5
6.35 10+5
Total Additional Charge Amount for Liquid Pipe (W
1.2. Compensating Rate (P).
O/U MODEL
RAS-8
RAS-10
RAS-12
1.3. Calculation of Total Additional Charge Amount (W kg)
Put weight W1 and precharge refrigerant for piping length (P)
Total Q'ty of Additional Charge W = W1 – P
2. Charging Work
Charge refrigerant (R410A) into the system according to the instructions described in the "Installation Manual".
3. Record of Additional Charge
Record the refrigerant charging quantity in order to facilitate maintenance and servicing activities.
Total refrigerant charge of this system is calculated in the following formula.
Additional Sub Total
Charge (Kg/m) Amount (Kg)
0.120 10 x 0.120 = 1.2
0.07 10 x 0.07 = 0.7
0.03 15 x 0.03 = 0.45
) = 2.35 kg
1
P (Kg)
1.6 ATTENTION:
It is not necessary to add or to extract the refrigerant if the
1.6
value of the calculation procedure is smaller than (P).
2.0
Example: W= 2.35
This System: W=
Total Additional Charge W
Total Ref. Charge of this System
Date of Ref. Charge Work
Year Month
Example =
Total Ref. Charge of This System =
This System =
ADDITIONAL REFRIGERANT CHARGE
kg)
1
- 1.6 = 0.75 Kg
- = Kg
Day
7.8 + 0.75 = 8.55 Kg
W + W =
0
+ = Kg
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