Refrigerant Piping Tasks; Refrigerant Piping System - Mitsubishi Electric City Multi PUMY-SP112VKM Technical & Service Manual

10

REFRIGERANT PIPING TASKS

10-1. REFRIGERANT PIPING SYSTEM

Line-Branch Method
Connection Examples
(Connecting to 4 Indoor Units)
Total Piping Length
Permissible
Farthest Piping Length
Length
Farthest Piping Length After First Branch
High/Low Difference in Indoor/Outdoor Section
Permissible High/
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)
(3) Section From Branch to
Branch (B,C)
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.)
OCH668B
A
B
A+B+C+a+b+c+d [ 120 m
(L) A+B+C+d [ 70 m
(R)
B+C+d [ 50 m
(H)
50 meters or less (If the outdoor unit is lower, 30 meters or less)
(h)
15 meters or less
Use an optional branch piping kit (CMY-Y62-G-E).
(1) Refrigerant Piping Diameter In Section
From Outdoor Unit to First Branch
(Outdoor Unit Piping Diameter)
Model
Each
PUMY-SP112
Section of
PUMY-SP125
Piping
PUMY-SP140
(3) Refrigerant Piping Diameter In Section
From Branch to Branch
Liquid Line (mm)
{9.52
<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
3.5 kg
<Example>
Outdoor model : SP125
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 + B + C + a = 20 + 5 + 5 + 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
A
L
R
B C
a b c
C
C C
Piping Diameter (mm)
Liquid Line
{9.52
Gas Line
{15.88
Gas Line (mm)
{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 20 m
B : ø9.52 5 m
C : ø9.52 5 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
130
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)
R[ 30 m
Liquid Line
50 or lower
R> 30 m
Gas Line
Liquid Line
63 to 140
Gas Line
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.
Amount for the
indoor units
1.5 kg
2.5 kg
3.0 kg
At the conditions
below:
{6.35
{9.52
{12.7
{9.52
{15.88