Refrigerant Piping Tasks; Refrigerant Piping System - Mitsubishi Electric PUMY-P125VMA Technical & Service Manual

11

REFRIGERANT PIPING TASKS

11-1. REFRIGERANT PIPING SYSTEM

Line-Branch Method
Connection Examples
(Connecting to Four 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 Pipng
(1) Section From Oudoor 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 of 3kg equivalent to 50-m 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
B
A+B+C+a+b+c+d is 100 meters or less
(L)
A+B+C+d is 70 meters or less
(R) B+C+d is 30meters or less
(H) 30 meters or less (If the outdoor unit is lower, 20 meters or less)
(h)
12 meters or less
Use an optional branch piping kit (CMY-Y62-C-E).
(1) Refrigerant Piping Diameter In Section
From Outdoor Unit to First Branch
(Outdoor Unit Piping Diameter)
Model
Each
Section of PUMY-P125
Piping
(3) Refrigerant Piping Diameter In Section
From Branch to Branch
Downstream Unit Model Total
80 or less
80 or more
<Additional Charge>
Additional
refrigerant charge
<Example>
Indoor 1 : 25
2 : 50
3 : 25
4 : 50
The total length of each liquid line is as follows
{9.52 : A + B + C + b + d = 10 + 10 + 10 + 10 + 10 = 50m
{6.35 : a + c = 5 + 10 = 15m
Therefore,
<Calculation example>
Additional
refrigerant charge = 50
75
L
R
B C
a
b c
C
C C
1
2 3
Piping Diameter (mm)
Liquid Line {9.52
Gas Line {19.05
Liquid Line (mm)
{9.52
{9.52
Liquid pipe size Liquid pipe size
Total length of Total length of
{9.52 0.06 {6.35
= +
(kg) (m) 0.06 (kg/m) (m)
A : {9.52 10m a : {6.35
B : {9.52 10m b : {9.52
C : {9.52 10m c : {6.35
d : {9.52
0.06 + 15 0.024 – 3.0 = 0.4kg (rounded up)
d
C
4
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)
Liquid Line
40 or lower
Gas Line
Liquid Line
50 to 80
Gas Line
Liquid Line
100, 125
Gas Line
Gas Line (mm)
{15.88
{19.05
Refrigerant
amount for outdoor
0.024 unit
–
0.024 (kg/m) 125: 3.0kg
5m
10m
At the conditions
below:
10m
10m
{6.35
{12.7
{9.52
{15.88
{9.52
{19.05