Vacuum drying
• Be sure to perform vacuuming from both liquid and gas sides.
• Be sure to use a vacuum pump equipped with the counter-flow prevention function so that oil in the pump will
not flow back into piping for air conditioners. (If oil in the vacuum pump enters in the air conditioner with R410A
refrigerant, a problem may be caused in the refrigerating cycle.)
After finishing the airtight test and discharging nitrogen gas, connect the gauge manifold to the service ports of the
liquid side, gas side, and balance pipe side and connect a vacuum pump as shown in the figure below. Be sure to
perform vacuuming for the liquid, gas, and balance pipe sides.
Main piping
Packed valve details
To outdoor unit
To gauge manifold
To
Gas-side valve
Liquid-side service port
outdoor
unit
Liquid-side valve
Balance
Gas-side
service port
service port
Piping at site
Piping at site
Balance
valve
Piping at site
• Use a vacuum pump with a high vacuuming degree [-100.7kPa (5Torr, -755mmHg)] and large exhaust gas
amount (40L/minute or larger).
• Perform vacuuming for 2 or 3 hours, though the time differs depending on the pipe length. Check that all the
packed valves at the liquid side, gas side, and balance pipe side are fully closed.
• If the pressure does not reach -100.7kPa or less, continue vacuuming for 1 hour or more. If the pressure does
not reach -100.7kPa after 3 hours of vacuuming, stop vacuuming and check for air leakage.
• If the pressure reaches -100.7kPa or less after vacuuming for 2 hours or more, close the valves VL and VH on
the gauge manifold fully and stop the vacuum pump. Leave it as it is for 1 hour to confirm that the vacuuming
degree does not change.
If the degree of vacuum loss is large, moisture may remain in the pipes. In that case, inject dry nitrogen gas and
apply pressure to 0.05MPa and perform vacuuming again.
• After finishing the above procedure of vacuuming, exchange the vacuum pump with a refrigerant canister and
advance to the additional charging of refrigerant.
133-EN
1117101201-3 EN.indd 67
1117101201-3 EN.indd 67
Low pressure
gauge
Connected to indoor unit
Packed valve fully closed
(gas side)
V
V
L
Header outdoor unit
Service port
Brazed
Fully
closed
Service port
Packed valve fully closed
Vacuum pump
(liquid side)
Fully
closed
Service port
Packed valve fully closed
(balance)
Follower units
– 67 –
Adding refrigerant
After finishing vacuuming, exchange the vacuum pump with a refrigerant canister and start additional charging of
refrigerant.
Calculation of additional refrigerant charge amount
Refrigerant charge amount at shipment from the factory does not include the refrigerant for pipes at the local site.
For refrigerant to be charged in pipes at the local site, calculate the amount and charge it additionally.
NOTE
High pressure
If the additional refrigerant amount indicates minus as the result of calculation, use the air conditioner without
gauge
additional refrigerant.
Gauge
H
Heat pump
Outdoor unit type
manifold
type
Charged amount (kg)
Outdoor unit type
Cooling only
type
Charged amount (kg)
Additional refrigerant charge amount at site = [1] + [2] + [3]
[1]. Compensation by system HP (Table 1)
[2]. Additional refrigerant charge amount Indoor unit (Table 2)
[3]. (Real length of liquid pipe × Additional refrigerant charge amount per liquid pipe 1 m (Table 3)) × 1.2
P
Table 1
System
HP
8
10
12
14
16
18
20
22
24
26
28
30
32
Standard model
34
36
38
40
42
44
46
48
50
52
54
56
58
60
20
22
36
High efficiency
38
40
model
42
44
54
MAP080 MAP100 MAP120 MAP140 MAP160 MAP180 MAP200 MAP220
11.5
MAP080 MAP100 MAP120 MAP140 MAP160 MAP180 MAP200 MAP220
10.5
Combination
Charged refrigerant (kg)
HP
Heat pump type
Cooling only type
8
–
–
11.5
10.5
10
–
–
11.5
10.5
12
–
–
11.5
10.5
14
–
–
11.5
11.5
16
–
–
11.5
11.5
18
–
–
11.5
11.5
20
–
–
11.5
11.5
22
–
–
11.5
11.5
12
12
–
23
21
14
12
–
23
22
16
12
–
23
22
16
14
–
23
23
16
16
–
23
23
18
16
–
23
23
20
16
–
23
23
22
16
–
23
23
20
20
–
23
23
22
20
–
23
23
22
22
–
23
23
16
16
14
34.5
34.5
16
16
16
34.5
34.5
18
16
16
34.5
34.5
20
16
16
34.5
34.5
22
16
16
34.5
34.5
20
20
16
34.5
34.5
22
20
16
34.5
34.5
22
22
16
34.5
34.5
10
10
–
23
21
12
10
–
23
21
12
12
12
34.5
31.5
14
12
12
34.5
32.5
14
14
12
34.5
33.5
14
14
14
34.5
34.5
16
14
14
34.5
34.5
20
20
14
34.5
34.5
11.5
Compensation by
System HP
kg
-3.5
-3.5
-1.5
-1.0
-0.5
1.5
1.5
1.5
-3.0
-2.5
-2.0
-1.5
-1.0
1.0
1.0
1.0
3.0
3.0
3.0
-6.5
-6.5
-0.5
-0.5
-0.5
2.5
2.5
2.5
-7.0
-7.0
-12.5
-10.5
-8.5
-4.5
-4.5
1.5
134-EN
8/8/2559 BE 3:49 PM
8/8/2559 BE 3:49 PM