Refrigerant Piping Tasks - Mitsubishi Electric CITY MULTI PUMY-P112VKM5 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
Permissible
Indoor/Outdoor Section
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.)
OCH740
A+B+C+a+b+c+d [ 300 m
(L) A+B+C+d [ 150 m
B+C+d [ 30 m
(R)
The outdoor unit is upper: 50 meters or less
(H) The outdoor unit is lower: 40 meters or less (30 meters or less if PKFY-P10/15/20/25/32VLM,
PFFY-P*VKM, PFFY-P*VCM, PFFY-P*VL* type of indoor units are included.)
15 meters or less
(h)
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
P112 Liquid Pipe
Section of
P125
Piping
Gas Pipe
P140
(3) Refrigerant Piping Diameter In Section
From Branch to Branch
Liquid Line (mm)
ø9.52
<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
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 + 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 50.0
40 × + 45 ×
1000 1000
127
A
A
B C
a b c
B
C
C C
(2) Refrigerant Piping Diameter In Section
Piping Diameter (mm)
ø9.52
ø15.88
Note:
Gas Line (mm)
When connecting the CONNECTION KIT (PAC-
ø15.88
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.
Pipe size Total capacity of connected indoor units
Liquid pipe
ø9.52
+
8.1 – 16.0 kW
(m) × 50.0 (g/m)
16.1 –
A: ø9.52 mm
B: ø9.52 mm
C: ø9.52 mm
a: ø9.52 mm
b: ø6.35 mm
c: ø6.35 mm
d: ø6.35 mm
+ 3.0 = 6.1kg (rounded up)
A Outdoor Unit
B First Branch
C Indoor unit
L
R
d
C
From Branch to Indoor Unit (Indoor Unit
Piping Diameter)
Model Piping Diameter (mm)
Liquid Pipe
– 50
Gas Pipe
Liquid Pipe
63 – 140
Gas Pipe
Amount for the indoor units
– 8.0 kW 1.5 kg
2.5 kg
3.0 kg
20 m
5 m
5 m
At the conditions
15 m
below:
10 m
10 m
20 m
ø6.35
ø12.7
ø9.52
ø15.88