Hitachi SET FREE Serie Manual De Instrucciones página 33

PIPING WORK AND REFRIGERANT CHARGE
8.3 VACUUMING
Connect a manifold gauge and vacuum pump to the check joints.
8.4 ADDITIONAL REFRIGERANT CHARGE CALCULATION
Although refrigerant has been charged into this unit in advance, additional refrigerant charge is required according to piping length.
Determine the additional refrigerant quantity according to the following procedure, and charge the system with it.
Record the additional refrigerant quantity to facilitate maintenance and servicing activities thereafter.
Calculating method of additional refrigerant charge (W kg)
Nº Symbol
Pipe diameter (mm)
∅22.2
∅19.05
∅15.88
∅12.7
∅9.52
∅6.35
1 W1
?
N O T E
In the case that the quantity calculated above is less than the minimum quantity indicated in the table below, adopt
the quantity in the table below as the additional refrigerant quantity for piping liquid, regardless of the piping length.
Minimum additional charge of base unit (kg)
For combination of the units, adopt the total minimum quantity of each base unit as the minimum additional
refrigerant quantity.
Additional refrigerant charge quantity for indoor unit (only for heat pump system) (W2 kg)
The additional refrigerant charge is required depending on the number of connected indoor units. Select the
refrigerant quantity from the following table.
Additional refrigerant charge quantity (kg)
System
2 W2
Model
Connectable
number
23 PMML0392B rev.1 - 07/2016
High/low pressure gas stop valve
Heat pump system
Liquid stop valve
High/low pressure gas stop valve
Heat recovery system Low pressure gas stop valve
Liquid stop valve
Additional refrigerant charge calculation for liquid piping (W1 kg)
Total piping length (m)
m
m
m
m
m
m
Total additional charge for liquid piping =
HP
RCI-2.0FSN3
1 0.0
2 0.5
3 0.5
4 or more 1.0
Contents
Refrigerant amount for 1m pipe
(kg/m)
× 0.36 =
× 0.26 =
× 0.17 =
× 0.11 =
× 0.056 =
× 0.024 =
5 6 8
2.0 2.0 2.0
Heat Pump
RCI-2.5FSN3 RCI-3.0-6.0FSN3
0.0 0.5
0.5 1.0
1.0 1.5
1.5 2.0
Additional
charge (kg)
Additional charge
(kg)
10 12 14 16
2.0 3.0 3.0 3.0
Heat Recovery
RCI-2.0-6.0FSN3
0.0
0.0
0.0
0.0
kg
kg