7
5.4. Selecting pipe size (Fig. 5-3)
A B
Liquid (mm)
ø9.52
The piping connection size differs according to the type
and capacity of indoor units. Match the piping connec-
tion size of branch box with indoor unit.
If the piping connection size of branch box does not
match the piping connection size of indoor unit, use
optional different-diameter (deformed) joints to the
branch box side. (Connect deformed joint directly to
the branch box side.)
Gas (mm)
ø15.88
Different-diameter joint (optional parts) (Fig. 5-4)
Model name
Connected pipes diameter
Diameter A
Diameter B
mm
mm
mm
MAC-A454JP
ø9.52
→
ø12.7
ø9.52
ø12.7
MAC-A455JP
ø12.7
→
ø9.52
ø12.7
ø9.52
MAC-A456JP
ø12.7
→
ø15.88
ø12.7
ø15.88
PAC-493PI
ø6.35
→
ø9.52
ø6.35
ø9.52
PAC-SG76RJ-E
ø9.52
→
ø15.88
ø9.52
ø15.88
Y-shape connection pipe for 100 type indoor unit (optional parts) (Fig. 5-5)
Model name
Connected pipe diameter
Diameter A
Diameter B
mm
mm
mm
PAC-AK52YP-E
Liquid
ø6.35
→
ø9.52
ø6.35
ø9.52
Gas
ø9.52
→
ø15.88
ø9.52
ø15.88
N
Installation procedure (Y-shape connection pipe)
Refer to the installation manuals of PAC-AK52YP-E.
Piping preparation
Table below shows the specifications of pipes commercially available.
Outside diameter
Insulation thickness
Insulation material
mm
mm
6.35
8
Heat resisting foam plastic
0.045 specific gravity
9.52
8
12.7
8
15.88
8
Ensure that the 2 refrigerant pipes are insulated to prevent condensation.
Refrigerant pipe bending radius must be 100 mm or more.
Caution:
Be sure to use the insulation of specified thickness. Excessive thickness may
cause incorrect installation of the indoor unit and branch box, and lack of
thickness may cause dew drippage.
2-branch pipe (Joint) : Optional parts (According to the connection method,
you can choose the favorite one.)
Model name
Connection method
MSDD-50AR-E
flare
MSDD-50BR-E
brazing
N
Installation procedure (2 branches pipe (Joint))
Refer to the installation manuals of MSDD-50AR-E and MSDD-50BR-E.
5. Installing the refrigerant piping
(1) Valve size for outdoor unit
For liquid
ø9.52 mm
For gas
ø15.88 mm
(2) Valve size for branch box
UNIT
Liquid pipe
ø6.35 mm
Gas pipe
ø9.52 mm
UNIT
Liquid pipe
ø6.35 mm
Gas pipe
ø9.52 mm
UNIT
Liquid pipe
ø6.35 mm
Gas pipe
ø9.52 mm
UNIT
Liquid pipe
ø6.35 mm
Gas pipe
ø9.52 mm
UNIT
Liquid pipe
ø6.35 mm
Gas pipe
ø12.7 mm
* 3-branch type : only
,
,
unit
B
A
Fig. 5-4
Fig. 5-3
A
B
B
B
B
B
Branch box
N
In case of using 1-branch box
Flare connection employed. (No. brazing)
N
In case of using 2-branch boxes
Branch box #1
2 branches pipe (joint)
: optional parts.
Branch box #2
Conversion formula
1/4 F
ø6.35
3/8 F
ø9.52
1/2 F
ø12.7
5/8 F
ø15.88
3/4 F
ø19.05
5.3. Addition of refrigerant
• Additional charging is not necessary for this unit if the total pipe length
(b1+b2+a1+a2+a3+a4+a5+a6+a7+a8) does not exceed 40 m.
• If the total pipe length exceeds 40 m, charge the unit with additional R410A
refrigerant according to the permitted pipe lengths in the chart below.
* When the unit is stopped, charge the unit with the additional refrigerant through
the liquid stop valve after the pipe extensions and indoor unit have been vacu-
umized.
When the unit is operating, add refrigerant to the gas check valve using a safety
charger. Do not add liquid refrigerant directly to the check valve.
After charging the unit with refrigerant, note the added refrigerant amount
on the service label (attached to the unit).
Refer to the “1.5. Using R410A refrigerant air conditioners” for more informa-
tion.
Table 1
Total piping length
(b1+b2+a1+a2+a3+a4+a5+a6+a7+a8)
41 - 50 m 51 - 70 m 71 - 90 m 91 - 115 m
Additional refrigerant charging amount
0.6 kg
1.4 kg
2.2 kg
3.2 kg
Additional refrigerant charging correction amount
Δ
R=0.01 [kg/m]
×
ø9.52 branch pipe (liquid pipe) total length [m]
Example) b1=20 m, b2=25 m
Indoor unit A
ø9.52 Liquid pipe
a1=12 m
Indoor unit B
ø6.35 Liquid pipe
a2=11 m
Indoor unit C
ø6.35 Liquid pipe
a6=14 m
Indoor unit D
ø9.52 Liquid pipe
a7=13 m
Total piping length : b1+b2+a1+a2+a6+a7=95 m
→
According to Table 1, the additional refrigerant charging amount is 3.2 kg.
Because indoor units with ø9.52 liquid pipes are connected (indoor units A and D in
this example), the additional refrigerant charging amount must be corrected.
Additional refrigerant charging correction amount
Δ
R =0.01 [kg/m]
×
ø9.52 branch pipe (liquid pipe) total length (a1+a7)
=0.01
×
(12+13 m)
=0.25
kg
Therefore, the additional refrigerant charging amount is 3.2 kg + 0.25 kg = 3.45 kg.
* Although two ø6.35 liquid pipes are used between the branch box and the Y-shape
connection pipe when connecting the P100 indoor unit, calculate the additional
refrigerant charging amount assuming only one ø9.52 liquid pipe is used.
If connecting an indoor unit with ø9.52 liquid pipes (model number 71 or more for M-
and S-Series and model number 60 or more for P-Series), the additional refrigerant
charging amount in Table 1 must be corrected (add the following
Δ
R value from the
value given in Table 1).
A
A
A
B
B
B
B
B
Fig. 5-5
B
A
