Refrigerant Piping Tasks; Refrigerant Piping System - Mitsubishi PUMY-P60NKMU 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
Permissible High/ High/Low Difference in Indoor/Outdoor Section
Low Difference
High/Low Difference in Indoor/Indoor Section
■
Selecting the Refrigerant Branch Kit
■
Select Each Section of Refrigerant Piping
(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 right table.
■
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.
• 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
32.92 kg, round up the charge to 33.0 kg.)
OCH502C
A
B
a
A+B+C+a+b+c+d 150m [492ft]
(L)
A+B+C+d 80m [262ft]
( )
B+C+d 30m [100ft]
(H)
50 meters [164ft] or less (If the outdoor unit is lower, 40 meters [131ft] or less)
(h)
15 meters [49ft] or less
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)
Piping Diameter (mm [inch])
Model
Liquid Line
PUMY-P60
Gas Line
(3) Refrigerant Piping Diameter In Section
From Branch to Branch
Liquid Line (mm [inch]) Gas Line (mm [inch])
9.52 [3/8]
<Additional Charge>
Additional Liquid pipe size
refrigerant charge Total length of
9.52
×
=
[3/8"
×
(kg) (m)
×
[lbs] [ft]
<Calculation example>
Outdoor model : P60
Indoor
1 : P24 A : 9.52 [3/8"] 10 m [33 ft]
2 : P15 B : 9.52 [3/8"] 10 m [33 ft]
3 : P08 C : 9.52 [3/8"] 10 m [33 ft]
4 : P06
The total length of each liquid line is as follows;
9.52 [3/8"] : A + B + C + a = 10 m + 10 m + 10 m + 15 m = 45 m [33 ft + 33 ft + 33 ft + 49 ft = 148 ft]
6.35 [1/4"] : b + c + d = 10 m +10 m + 20 m = 40 m [33 ft + 33 ft + 66 ft = 132 ft]
The total capacity of connected indoor units is as follows:
24 + 15 + 08 + 06 = 53
Therefore, the additional refrigerant
charge is as follows = 45 m × 0.07 kg + 40 m × 0.027 kg + 2.5 kg = 6.8 kg (rounded up)
= [147 ft × 0.047 lbs + 132 ft × 0.018 lbs + 5.5 lbs = 14.8 lbs]
103 103
L
d
C
b c
(2) Refrigerant Piping Diameter In Section
From Branch to Indoor Unit
(Indoor Unit Piping Diameter)
Model number
9.52 [3/8]
18 or lower
19.05 [3/4]
24 to 54
72
19.05 [3/4]
Liquid pipe size
Total length of
× ×
0.07 kg 6.35 0.027 kg
×
+
0.047 lbs] [1/4" 0.018 lbs]
×
0.07 (kg/m), (m) 0.027 (kg/m),
×
0.047 [lbs/ft] [ft] 0.018 [lbs/ft]
a : 9.52 [3/8"]
b : 6.35 [1/4"]
c : 6.35 [1/4"]
d : 6.35 [1/4"]
A Outdoor Unit
B First Branch
C Indoor unit
Piping Diameter (mm [inch])
Liquid Line 6.35 [1/4]
Gas Line 12.7 [1/2]
Liquid Line 9.52 [3/8]
Gas Line 15.88 [5/8]
Liquid Line 9.52 [3/8]
Gas Line 19.05 [3/4]
Total capacity of Amount for the
connected indoor indoor units
units
+
~P42 2.0kg [4.4lbs]
P43 ~ P60 2.5kg [5.5lbs]
3.0kg [6.6lbs]
P61~
15m [49 ft]
At the
10m [33 ft]
conditions
10m [33 ft]
below:
20m [66 ft]