Mitsubishi Electric PUMY-P112VKM3 Technical & Service Manual page 140

Header-Branch Method
Connection Examples
(Connecting to 4 Indoor Units)
Total Piping Length
Permissible
Farthest Piping Length
Length
Farthest Piping Length After First Branch
Permissible High/ High/Low Difference in Indoor/Outdoor Section
Low Difference
High/Low Difference in Indoor/Indoor Section
■
Selecting the Refrigerant Branch Kit
■
Select Each Section of Refrigerant Piping
(1) Section From Outdoor Unit
to First Branch (A)
(2) Sections From Branch to
Indoor Unit (a,b,c,d)
Select the size from the table to the right.
■
Additional refrigerant charge
Refrigerant for the extended piping is not included in the
outdoor unit when the unit is shipped from the factory.
Therefore, charge each refrigerant piping system with
additional refrigerant at the installation site. In addition, in
order to carry out service, enter the size and length of each
liquid pipe and additional refrigerant charge amounts in
the spaces provided on the "Refrigerant amount" plate on
the outdoor unit.
Calculation of additional refrigerant charge
• Calculate the additional charge using the liquid pipe size
and length of the extended piping and total capacity of
connected indoor units.
• Calculate the additional refrigerant charge using the
procedure shown to the right, and charge with the
additional refrigerant.
• For amounts less than 0.1 kg, round up the calculated
additional refrigerant charge.
(For example, if the calculated charge is 6.01 kg, round up
the charge to 6.1 kg.)
OCH632A
A
A
B
a
C
A+a+b+c+d [ 300 m
(L)
A+d [ 150 m
(R)
d is 30 meters or less
(H)
50 meters or less (If the outdoor unit is lower, 40 meters or less)
(h)
15 meters or less
Please select branching kit, which is sold separately, from the table below.
(The kit comprises sets for use with liquid pipes and for use with gas pipes.)
Branch header (4 branches)
CMY-Y64-G-E
(1) Refrigerant Piping Diameter In Section
From Outdoor Unit to First Branch (Out-
door Unit Piping Diameter)
Each
Model
Section of
PUMY-P112
Piping
PUMY-P125
PUMY-P140
Note:
When connecting the CONNECTION KIT (PAC-LV11M-J) and an M-series indoor unit, refer to the
installation manual for the CONNECTION KIT when selecting the pipe size and piping length.
<Additional Charge>
Calculation of refrigerant charge
Pipe size
Liquid pipe
ø6.35
(m) × 19.0 (g/m)
Included refrigerant amount when shipped from the factory
Included refrigerant amount
4.8 kg
<Example>
Outdoor model : P125
Indoor 1 : P63 (7.1 kW)
2 : P40 (4.5 kW)
3 : P25 (2.8 kW)
4 : P20 (2.2 kW)
The total length of each liquid line is as follows:
ø9.52 : A + a = 30 + 15 = 45 m
ø6.35 : b + c + d = 10 + 10 + 20 = 40 m
The total capacity of connected indoor unit is as follows:
7.1 + 4.5 + 2.8 + 2.2 = 16.6
<Calculation example>
Additional refrigerant charge
19.0
40 ×
1000
L
r
b c
C
c
Branch header (8 branches)
CMY-Y68-G-E
Piping Diameter (mm)
Liquid Line
{9.52
Gas Line
{15.88
Total capacity of
Pipe size
connected indoor units
Liquid pipe
+ +
up to 8.0 kW
ø9.52
8.1 to 16.0 kW
(m) × 50.0 (g/m)
16.1 kW or above
A : ø9.52 30 m
a : ø9.52 15 m
b : ø6.35 10 m
c : ø6.35 10 m
d : ø6.35 20 m
50.0
+ 45 × + 3.0 = 6.1 kg (rounded up)
1000
140
d
C
A Outdoor Unit
B First Branch
C Indoor unit
(2) Refrigerant Piping Diameter In Section
From Branch to Indoor Unit (Indoor Unit
Piping Diameter)
Model number Piping Diameter (mm)
Liquid Line
50 or lower
Gas Line
Liquid Line
63 to 140
Gas Line
Amount for the
indoor units
1.5 kg
2.5 kg
3.0 kg
At the conditions
below:
{6.35
{12.7
{9.52
{15.88