Refrigerant Piping System - Mitsubishi Electric CITY MULTI PUHY-P-YSMF-B Manuel D'installation

10.2. Refrigerant piping system

Line-branch method
Connection examples
(connecting to six indoor units)
Item
Total piping length
Indoor
Farthest piping length
side
Farthest piping length after first branch (r)
Oil balance pipe
Outdoor
side
Distributer (liquid)/Variable capacity unit, Constant capacity unit
Distributer (gas)/Constant capacity unit
Indoor/Outdoor
Permissible high/
Low difference Indoor/Indoor
Variable capacity unit/Constant capacity unit
Selecting the refrigerant branch kit
Use the table to the right to make the selection based
on the model total of indoor units downstream from the
branch section.
Select each section of refrigerant piping
(1) Section from outdoor unit to first
branch (C)
(2) Sections from branch to indoor
unit (a, b, c, d, e, f)
(3) Section from branch to branch
(D, E, F, G)
Select the size from the table to the right.
Variable capacity unit Constant capacity unit
400 500 200
16 22 6.5
Additional refrigerant charge
The outdoor unit is charged with refrigerant at the time of ship-
ping according to the chart above. As this charge does not
include the amount needed for extended piping, additional charg-
ing for each refrigerant line will be required 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 out-
door 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 in a fraction of less than 0.1 kg, round
up to the next 0.1 kg. For example, if the result of the calcu-
lation was 23.28 kg, round the result up to 23.3 kg.
• If the total amount of refrigerant including the amount of re-
frigerant sealed in the outdoor unit when shipped from the
factor plus additional refrigerant for extension piping exceeds
73 kg, use 73 kg as the total amount of refrigerant.
Amount of refrigerant when shipped from factory + added
refrigerant 73 kg.
=
14
Constant Variable
Constant Variable
capacity unit capacity unit
capacity unit capacity unit
A G B
Note 1
Note 1
Distributer
Distributer
(liquid)
(liquid)
Distributer Distributer
(gas)
(gas)
C
a
First branch
First branch
Ind oor Indoor
unit
unit
1
Note 1: Because it is built into the variable capacity unit, B is used to carry liquid only. Set the constant capacity unit and
variable capacity unit in accordance with the G dimension given in the figure above (G = 0.01 m).
Piping components
A+B+C+D+E+F+G+a+b+c+d+e+f
(L) A (B)+C+D+E+F+G+f
A, B (Liquid line)
Outdoor upper
Outdoor lower
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 to 630
631 or more
(1) Refrigerant piping diameter in section from outdoor
unit to first branch (outdoor unit piping diameter)
Model
Each section
PUHY-P600YSMF-B
of piping
PUHY-P650YSMF-B
PUHY-P700YSMF-B
PUHY-P750YSMF-B
(3) Refrigerant piping diameter in section from
branch to branch
Downstream unit
model total
80 or less
81 to 160
161 to 330
(kg)
331 to 480
481 to 630
250
631 or more
8.5
<Additional charge>
Liquid pipe size
total length of
ø19.05 × 0.29
+
(m) × 0.29 (kg/m)
<Example> Indoor 1 : 125
The total length of each liquid line is as follows
ø19.05 : C = 40 m
ø15.88 : B + D + E = 1 + 10 + 5 = 16 m
ø12.7 : A + F + G = 3 + 5 + 5 = 13 m
ø9.52 : a + b + c + d + e = 50 m
ø6.35 : f = 5 m
Therefore,
<Calculation example>
Additional
refrigerant charge = 40 × 0.29 +16 × 0.25 + 13 × 0.12 +
Constant Constant
capacity unit capacity unit
Oil balance pipe (optional) I Oil balance pipe (optional) I
(for distribution within the unit) (for distribution within the unit)
Gas line A
Gas line A
Liquid line A
Liquid line A
Gas line (main) C
Gas line (main) C
L
R
D E F G
b c d e
Ind oor Ind oor Ind oor Ind oor
Indoor Indoor Indoor Indoor
unit unit unit
unit
unit unit unit unit
Ind oor
2 3 4 5
D+E+F+G+f
The included oil balance pipe must be used. If any other piping is used, the length
I of the oil balance pipe must be no more than 3 m (max. equivalent length 4 m),
and height from the bottom of the unit must be no more than 0.1 m.
A (Gas line)
H
H
h
– Must be installed on same frame, and there must be no high/low difference.
Branch kit model
CMY-Y102S-F
CMY-Y102L-F
CMY-Y202-F
CMY-Y302-F
(2) Refrigerant piping diameter in section from branch
Piping diameter (mm)
Liquid line Gas line
ø19.05 ø38.1
ø19.05 ø44.45
ø19.05 ø44.45
ø19.05 ø44.45
Gas line
Liquid line
(mm) (mm)
ø9.52 ø15.88
ø12.7 ø19.05
ø25.4
ø12.7
ø15.88 ø31.75
ø15.88 ø38.1
ø44.45
ø19.05
Liquid pipe size Liquid pipe size
total length of total length of
ø15.88 × 0.25 ø12.7 × 0.12
+
(m) × 0.25 (kg/m) (m) × 0.12 (kg/m)
A : ø12.7 3 m
2 : 125 B : ø15.88 1 m
3 : 125 C : ø19.05 40 m
4 : 125 D : ø15.88 10 m
5 : 100 E : ø15.88 5 m
6 : 40 F : ø12.7 5 m
G : ø12.7 5 m
50 × 0.06 + 5 × 0.024 + 3.0 = 23.3 kg
Variable Variable
capacity unit capacity unit
Distributer (gas) (optional) Distributer (gas) (optional)
Gas line B Gas line B
Liquid line B
Liquid line B
Distributer (liguid) (optional) Distributer (liguid) (optional)
Liquid line (main) C
Liquid line (main) C
:indicates piping connection points :indicates piping connection points
To down stream units
To down stream units
A
f
Note:
• The model total for downstream units shown
in the table below is the model total when
Indoor
viewed from Point A in the drawing above.
unit
unit
6
• With the exception of PUHY-P600YSMF-B,
the first branch is always CMY-Y302-F.
Tolerance
220 m or less
100 m or less (Max. equivalent length 125 m)
40 m or less
4 m or less (Max. equivalent length 5 m)
4 m or less (Max. equivalent length 5 m)
50 m or less
40 m or less
15 m or less
to indoor unit (indoor unit piping diameter)
Model number Piping diameter (mm)
Liquid line
20 · 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 Liquid pipe size
total length of total length of
ø9.52 × 0.06 ø6.35 × 0.024
+ +
(m) × 0.06 (kg/m) (m) × 0.024 (kg/m)
a :ø9.52 15 m
b :ø9.52 15 m
c :ø9.52 10 m At the conditions
d :ø9.52 5 m
below:
e :ø9.52 5 m
f :ø6.35 5 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 to 630
Models 631 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
4.0 kg