Toshiba MMU-AP0091H Installation Manual page 34

5-16. Charging the System with Additional Refrigerant
After the system has been vacuumed, replace the vacuum pump with a refrigerant cylinder and charge the
system with additional refrigerant.
Calculating of additional refrigerant charge amount
Refrigerant in the system when shipped from the factory
Refrigerant amount
charged in factory
When the system is charged with refrigerant at the factory, the amount of refrigerant needed for the pipes at the
site is not included. Calculate the additional amount needed, and add that amount to the system.
(Calculation)
Additional refrigerant charge amount is calculated from size of liquid pipe at site and its real length.
Additional refrigerant charge amount at site =
Real length of liquid pipe × Additional refrigerant charge amount + compensation by system HP (Table 2)
Example : Additional charge amount R (kg) = (L1 x 0.025kg/m) + (L2 x 0.055kg/m) + (L3 x 0.105kg/m) + (3.0kg)
Table 1
Pipe dia. at liquid side
Additional refrigerant amount/1m
Table 2
Combined
Outdoor combination
horse power
(HP)
5 5
6 6
8 8
10 10
12 12
14 8 6
16 8 8
18 10 8
20 10 10
12 10
22
8 8
12 12
24
8 8
26 10 8
Heat pump model
Cooling only model
per liquid pipe 1m (Table 1)
L1 : Real total length of liquid pipe Ø6.4 (m)
L2 : Real total length of liquid pipe Ø9.5 (m)
L3 : Real total length of liquid pipe Ø12.7 (m)
System : 20HP
Ø6.4
0.025kg
C
(Compensation)
(HP)
(kg)
0.0
0.0
1.5
2.5
3.5
0.0
0.0
0.0
3.0
5.0
6 0.0
7.0
8 –4.0
8 –4.0
5HP 6HP
8.5kg 8.5kg
8.0kg 8.0kg
Ø9.5 Ø12.7
0.055kg 0.105kg
Combined
Outdoor combination
horse power
(HP)
28 10
30 10
12
32
8
12
34
10
12
36
10
38 10
40 10
42 12
44 12
46 12
48 12
34
R410A
8HP 10HP
12.5kg 12.5kg
11.0kg 11.0kg
Ø15.9 Ø19.0
0.160kg 0.250kg
(Compensation)
(HP)
10 8
10 10
10 10
8 8 8
12 10
8 8 8
12 12
10 8 8
10 10 8
10 10 10
10 10 10
12 10 10
12 12 10
12 12 12
12HP
12.5kg
11.0kg
Ø22.2
0.350kg
C
(kg)
–2.0
0.0
1.0
–6.0
3.0
–6.0
4.0
–6.0
–6.0
–5.0
–4.0
–2.0
0.0
2.0