Refrigerant Piping System - Mitsubishi Electric CITY MULTI PUHY-P-YMF-B Installation Manual

10.2. Refrigerant piping system

Line-Branch Method
Connection Examples
(Connecting to Five Indoor Units)
Total Piping Length
Permissible
Farthest Piping Length
Length
Farthest Piping Length After First Branch (r)
Permissible High/ High/Low Difference in Indoor/Outdoor Section (H)
Low Difference High/Low Difference in Indoor/Indoor Section (h)
Selecting the Refrigerant Branch Kit
Use the table to the right to make the selection
based on the model total of indoor units down-
stream from the branch section.
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,e)
(3) Section From Branch to
Branch (B, C, D)
Select the size from the table to the right.
Additional Refrigerant Charge
At the time of shipping, the outdoor unit PUHY-P400
is charged with 16 kg of refrigerant and the PUHY-
P500 is charged with 22 kg. As this charge does not
include the amount needed for extended piping, ad-
ditional charging for each refrigerant line will be re-
quired on site. In order that future servicing may be
properly provided, always keep a record of the size
and length of each refrigerant line and the amount of
additional charge by writing it in the space provided
on the outdoor unit.
Calculation of Additional Refrigerant Charge
• Calculate the amount of additional charge based
on the length of the piping extension and the size
of the refrigerant line.
• Use the table to the right as guide to calculating
the amount of additional charging and charge the
system according.
• If the calculation results of the calculation result
in a fraction of less than 0.1 kg, round up to the
next 0.1 kg. For example, if the result of the cal-
culation was 16.76 kg, round the result up to 16.8
kg.
A
B
a
C
1
A+B+C+D+a+b+c+d+e is 220 m or less
(L) A+B+C+D+e is 100 m or less
B+C+D+e is 30 m or less
50 m or less (If the outdoor unit is lower, 40 m or less)
15 m or less
Select the branch kit, sold separately, from the table below. (Each kit contains a refrigerant and
gas piping set.)
Downstream Unit Model Total
160 or less
161 to 330
331 or more
(1) Refrigerant Piping Diameter In Section
From Outdoor Unit to First Branch (Out-
door Unit Piping Diameter)
Model
Each
Section of
PUHY-P400
Piping
PUHY-P500
(3) Refrigerant Piping Diameter In Section
From Branch to Branch
Downstream Unit
Model Total
80 or less
81 to 160
161 to 330
331 to 480
481 or more
<Additional Charge>
Liquid pipe size
Total length of
ø15.88 × 0.25
(m) × 0.25 (kg/m)
<Example>
Indoor 1 : 125
2 : 100
3 : 50
4 : 32
5 : 32
The total length of each liquid line is as follows:
ø15.88 : A = 40 m
ø12.7 : B + C = 10 + 5 = 15 m
ø9.52 : D + a + b + c = 5 + 10 + 10 + 10 = 35 m
ø6.35 : d + e = 5 + 10 = 15 m
Therefore,
<Calculation example>
Additional
refrigerant charge = 40 × 0.25 + 15 × 0.12 + 35 × 0.06
A
A
L
R
e
B C D
b c d
C C C
2 3 4
Branch Kit Model
CMY-Y102S-F
CMY-Y102L-F
CMY-Y202-F
(2) Refrigerant Piping Diameter In Section
Piping Diameter (mm)
Liquid Line ø15.88
Gas Line ø31.75
Liquid Line ø15.88
Gas Line ø38.1
Liquid Line Gas Line
(mm) (mm)
ø9.52 ø15.88
ø12.7 ø19.05
ø12.7 ø25.4
ø15.88 ø31.75
ø15.88 ø38.1
Liquid pipe size Liquid pipe size
Total length of Total length of
ø12.7 × 0.12 ø9.52 × 0.06
+ +
(m) × 0.12 (kg/m) (m) × 0.06 (kg/m)
A : ø15.88 40 m a : ø9.52
B : ø12.7 10 m b : ø9.52
C : ø12.7 5 m c : ø9.52
D : ø9.52 5 m d : ø6.35
e : ø6.35
+ 15 × 0.024 + 2.5 = 16.8 kg
D
Note:
The model total for down-
stream units shown in the
table below is the model
total when viewed from
Point A in the drawing
above.
A Outdoor Unit
B First Branch
The first branch on the
outdoor unit must be
the CMY-Y202-F.
C Indoor unit
C
5
D To downstream units
From Branch to Indoor Unit (Indoor Unit
Piping Diameter)
Model number Piping dia. (mm)
Liquid Line
25 · 32 · 40
Gas Line
Liquid Line
50 · 63 · 71 · 80
Gas Line
Liquid Line
100 · 125 · 140
Gas Line
Liquid Line
200
Gas Line
Liquid Line
250
Gas Line
Liquid pipe size
Total length of
ø6.35 × 0.024
+
(m) × 0.024 (kg/m)
10 m
10 m
At the conditions
10 m
below:
5 m
10 m
Value of α
Total capacity of
connecting indoor units
to Model 80
Models 81 to 160
Models 161 to 330
Models 331 to 480
Models 481 or more
ø6.35
ø12.7
ø9.52
ø15.88
ø9.52
ø19.05
ø12.7
ø25.4
ø12.7
ø28.58
+ α
α
1.0 kg
1.5 kg
2.0 kg
2.5 kg
3.0 kg
13