Mitsubishi Electric PUMY-P112VKM3, Technical & Service Manual

Page: 142 / 158

142
10-2. REFRIGERANT PIPING SYSTEM (WHEN USING BRANCH BOX)
* 1 Branch box should be placed within the level between the outdoor unit and indoor units.
Branch box Method
Connection Examples
(Connecting to 8 Indoor Units)
Liquid Line
Gas Line
Piping Diameter (mm) Model
15 to 42
71
60 to 100
35,50
50
60
{
9.52
{
6.35
{
9.52
{
6.35
{
6.35
Model number A Liquid pipe B Gas pipe Indoor unit series
M series or
S series
P series
{
6.35
{
15.88
{
12.7
{
15.88
{
12.7
{
15.88
{
9.52
A + B + C + a + b + c + d + e + f + g + h ≦ 150 m
A + C + h ≦ 80 m
A + B + C ≦ 55 m
l ≦ 25m
a + b + c + d + e + f + g + h ≦ 95 m
H ≦ 50 m (In case of that outdoor unit is set higher than indoor unit)
H ≦ 40 m (In case of that outdoor unit is set lower than indoor unit)
h1 + h2 ≦ 15 m
h2 ≦ 15 m
h3 ≦ 12 m
≦
15
Total piping length
Farthest piping length (L)
Piping length between outdoor unit and branch boxes
Farthest piping length after branch box (I)
Total piping length between branch boxes and indoor units
In indoor/outdoor section (H)*
1
In branch box/indoor unit section (h1)
In each branch unit (h2)
In each indoor unit (h3)
Permissible
length
(One-way)
Permissible
height
difference
(One-way)
■
Select Each Section of Refrigerant Piping
■
Additional refrigerant charge
Select the size from the table to the right.
(1) Refrigerant Piping Diameter In Section From Outdoor Unit to Branch box (Outdoor Unit Piping Diameter)
(1) Section From Outdoor Unit
to Branch box (A, B, C)
(2) Sections From Branch box
to Indoor Unit (a to h)
(2) Refrigerant Piping Diameter In Section From Branch box to Indoor Unit (Indoor Unit Piping Diameter)
Each
Section of
Piping
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 and total capacity of
connected indoor units.
• 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 6.01 kg, round up
the charge to 6.1 kg.)
• In the calculation for the additional refrigerant charge, use
11.2 kW for the cylinder unit or hydrobox.
{
9.52
{
15.88
PUMY-P112
PUMY-P125
PUMY-P140
<Additional Charge>
Calculation of refrigerant charge
Pipe size
Liquid pipe
+
Pipe size
Liquid pipe
+
Total capacity of
connected indoor units
Amount for the
indoor units
ø6.35 ø9.52
up to 8.0 kW 1.5 kg
(m) × 19.0 (g/m) (m) × 50.0 (g/m)
8.1 to 16.0 kW 2.5 kg
16.1 kW or above 3.0 kg
Included refrigerant amount when shipped from the factory
Included refrigerant amount
40 ×
19.0
+ 45 ×
50.0
+ 3.0 = 6.1 kg (rounded up)
1000 1000
<Example>
Outdoor model : P125
Indoor 1 : P63 (7.1 kW)
A : ø9.52 30 m
a : ø9.52 15 m
2 : P40 (4.5 kW) b : ø6.35 10 m
3 : P25 (2.8 kW) c : ø6.35 10 m
4 : P20 (2.2 kW) d : ø6.35 20 m
The total length of each liquid line is as follows:
ø9.52 : A + a = 30 + 15 = 45 m
ø6.35 : b + c + d = 10 + 10 + 20 = 40 m
The total capacity of connected indoor unit is as follows:
7.1 + 4.5 + 2.8 + 2.2 = 16.6
<Calculation example>
Additional refrigerant charge
At the conditions
below:
4.8 kg
Number of bends
A
B
C
L
h2
H
A
Outdoor unit
B
Branching joint
C
Branch box
D
Indoor unit
a
b
d c e f g h
l
h2
H
h1
h3
C
A
B
C
D
D D D
D
D
D
D
OCH632A