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9-9. Additional refrigerant charge
Charge refrigerant in a liquid state.
- Charging refrigerant in the gaseous state will change the composition of the refrigerant and lead
to a performance drop.
Do not use a charging cylinder when charging refrigerant.
- The use of a charging cylinder may change the composition of the refrigerant and lead to a
performance drop.
The amount of refrigerant that is shown in the table below is factory-charged in the outdoor units. The amount
necessary for extended piping is not included and needs to be added on site.
Unit model
Factory-charged amount [kg]
m-MOCU-G02-050
The amount of refrigerant that is shown in the table below is the maximum amount to be added on site.
Configuration
Single-outdoor-unit system
Two-outdoor-unit system
Both refrigerant overcharge and undercharge will cause problems. Charge the system with the proper amount of
refrigerant.
Record the added refrigerant amount on the label attached to the control box panel for future servicing.
9-9-1. Calculation of the amount of additional refrigerant
・The amount of refrigerant to be added depends on the size and the total length of the liquid piping.
・Calculate the amount of refrigerant to be charged according to the formula below.
・Round up the calculation result to the nearest 0.1 kg.
<Formula>
・ When the piping length from the outdoor unit to the farthest indoor unit is 30.5 m (100 ft) or shorter
Amount of additional
charge (kg)
・When the piping length from the outdoor unit to the farthest indoor unit is longer than 30.5 m (100 ft)
Amount of additional
charge (kg)
VG79D920H01
11.8
Maximum amount to be added [kg]
40.0
99.9
ø19.05 total length
ø15.88 total length
=
+
× 0.29 (kg/m)
× 0.2 (kg/m)
Outdoor unit configuration
+
Single-outdoor-unit system
Two-outdoor-unit system
ø19.05 total length
ø15.88 total length
=
+
× 0.26 (kg/m)
× 0.18 (kg/m)
Outdoor unit configuration
+
Single-outdoor-unit system
Two-outdoor-unit system
ø12.7 total length
+
× 0.12 (kg/m)
Total capacity of connected
Amount (kg)
6.0
Total capacity ≤ 37 kW
12.0
37 kW ˂ Total capacity ≤ 44 kW
+
44 kW ˂ Total capacity ≤ 54 kW
54 kW ˂ Total capacity ≤ 71 kW
71 kW ˂ Total capacity
ø12.7 total length
+
× 0.11 (kg/m)
Total capacity of connected
Amount (kg)
6.0
Total capacity ≤ 37 kW
12.0
37 kW ˂ Total capacity ≤ 44 kW
+
44 kW ˂ Total capacity ≤ 54 kW
54 kW ˂ Total capacity ≤ 71 kW
71 kW ˂ Total capacity
26
Amount (kg)
indoor units
Amount (kg)
indoor units
3
3.5
4.5
5
6
3
3.5
4.5
5
6
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