Mitsubishi Electric PUMY-P100VHMB Service Manual page 88

Header-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)
Select the size from the table to the right.
■
Additional refrigerant charge
• Refrigerant of 3kg equivalent to 50m total
extended piping length is already included
when the outdoor unit is shipped.
Thus, if the total extended piping length is
50m or less, there is no need to charge with
additional refrigerant.
• If the total extended piping length exceeds
50m, calculate the required additional
refrigerant charge using the procedure
shown on the right.
• If the calculated additional refrigerant charge
is a negative amount, do not charge with any
refrigerant.
A
a
A+a+b+c+d
(L)
A+d 80m
( ) d is 30 meters or less
(H)
50 meters or less (If the outdoor unit is lower, 20 meters or less)
(h)
12 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
Piping
PUMY-P100-140
<Additional Charge>
Additional
refrigerant charge
<Example> Outdoor : 125
Indoor 1 : 63
2 : 40
3 : 25
4 : 20
The total length of each liquid line is as follows;
9.52 : A + a = 30 + 15 = 45m
6.35 : b + c + d = 10 + 10 + 20 = 40m
<Calculation example>
Additional
refrigerant charge = 45
L
b c
120m
Branch header (8 branches)
Piping Diameter (mm)
Liquid Line 9.52
Gas Line 15.88
Liquid pipe size
Total length of
9.52 × 0.06
= +
(kg) (m) × 0.06 (kg/m)
A : 9.52 30m a : 9.52
b : 6.35
c : 6.35
d : 6.35
0.06 + 40 0.024 – 3.0 = 0.7kg (rounded up)
× ×
88
d
A Outdoor Unit
B First Branch
C Indoor unit
CMY-Y68-G-E
(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
Liquid pipe size Refrigerant
Total length of amount for outdoor
6.35 × 0.024 unit
–
(m) × 0.024 (kg/m)
15m
10m
At the conditions
10m below:
20m
6.35
12.7
9.52
15.88
3.0kg