Refrigerant Piping System; Additional Refrigerant Charge; Calculation Of Additional Refrigerant Charge - Mitsubishi Electric PURY-P200YHM-A(-BS) Manuel D'installation

9.2. Refrigerant piping system

Connection example
[Fig. 9.2.1] (P.3, 4)
Outdoor model
Low-pressure side
Liquid pipe
High-pressure gas pipe
Liquid pipe
Model number
Outdoor twinning kit
A Outdoor unit
C BC controller (main)
E Indoor unit (15 ~ 80)
G Outdoor twinning kit
*1 The pipe sizes listed in columns A1 to A2 in this table correspond to the sizes
for the models listed in the unit 1 and 2 columns. When the order of unit 1 and
2 is changed, make sure to use the appropriate pipe size for the model.

10. Additional refrigerant charge

At the time of shipping, the outdoor unit is charged with refrigerant.
This charge does not include the amount needed for extended piping and
additional charging of 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 outdoor unit.
<Additional charge>
High-pressure
Additional refrigerant pipe size
charge Total length of ø28.58
=
×0.36
(kg) (m)×0.36(kg/m)
Liquid Piping Size Liquid Piping Size
Total length of ø12.7 Total length of ø9.52
+ +
×0.12 ×0.06
(m)×0.12(kg/m) (m)×0.06(kg/m)
BC controller
Total Outdoor Unit
(Standard/Main)
Model Name
Per Unit
+ P200 2.0kg
P250
3.0kg
P300
P350
4.5kg
P400
P450 5.0kg
P500
P550 6.0kg
P600
P650
7.5kg
P700
P750
9.0kg
P800
<Example>
Indoor 1: 80 A: ø28.58 40 m
2: 250 B: ø9.52 10 m
3: 32 C: ø9.52 20 m
4: 40 D: ø9.52 5 m
5: 32 E: ø9.52 5 m
6: 63 F: ø22.2 3 m
G: ø19.05 1 m
High-pressure side
Total capacity of indoor units
Gas pipe
Low-pressure gas pipe
B BC controller (standard)
D BC controller (sub)
F Indoor unit (100 ~ 250)
High-pressure
pipe size
Total length of ø22.2 Total length of ø19.05
+ +
×0.23
(m)×0.23(kg/m)
Liquid Piping Size
Total length of ø6.35
+
×0.024
(m)×0.024(kg/m)
BC controller
(Main) HA-type
+ +
2.0 kg
a: ø9.52 10 m
b: ø9.52 5 m
c: ø6.35 5 m At the
d: ø6.35 10 m conditions
e: ø6.35 5 m below:
f: ø9.52 5 m
Precautions for outdoor unit combinations
Refer to [Fig. 9.2.2] for the positioning of twinning pipes.
[Fig. 9.2.2] (P.5)
<A> The piping from the outdoor units to twinning pipe must be made to slope
downwards the twinning pipe. (high-pressure side only)
<B> Slope of twinning pipes (high-pressure side only)
Make sure the slope of the twinning pipes are at an angle within ±15° to the
ground.
If the slope exceeds the specifi ed angle, the unit may be damaged.
<C> Pipe connection example
The distributor on the low-pressure side must be placed in the outdoor
unit that has a larger capacity index of the two, regardless of the relative
positions of the outdoor units or their addresses.
(If outdoor units that have the same capacity are used in combination, the
distributor can be placed in either outdoor unit.)
If the distributor is placed in the outdoor unit that has a smaller capacity,
refrigerant will not be properly distributed and compressor failure may result.
Downward slope
A
BC controller
C
Slope of the twinning pipe is at an angle within ±15° to the ground
E
Twinning pipe (low-pressure side)
F
On-site piping (low-pressure connecting pipe: between outdoor units)
H
On-site piping (low-pressure main pipe: to BC controller)
I
On-site piping (high-pressure main pipe: to BC controller)
J
Straight run of pipe that is 500 mm or more
K
10.1. 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 below as a guide for calculating the amount of additional
charging and then charge the system accordingly.
• 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 calculation was 27.73 kg, round the
result up to 27.8 kg.
High-pressure High-pressure
pipe size pipe size
Total length of ø15.88
+
×0.16 ×0.11
(m)×0.16(kg/m) (m)×0.11(kg/m)
BC controller BC controller
(Sub) Total Units (Sub) Per Unit
1 1.0 kg
2 2.0 kg
The total length of each liquid line is as follows:
ø28.58: A = 40 m
ø22.2: F = 3 m
ø19.05: G = 1 m
ø9.52: C + D + E + a + b + f = 50 m
ø6.35: c + d + e = 20 m
Therefore,
<Calculation example>
Additional refrigerant charge
= 40 × 0.36 + 3 × 0.23 + 1 × 0.16 + 50 × 0.06 + 20 × 0.024 + 2 + 2 + 5
= 27.8 kg
Upward slope
B
Twinning pipe
D
Twinning pipe (high-pressure side)
G
Liquid Piping Size
Total length of ø15.88
+
×0.2
(m)×0.2(kg/m)
Total Capacity of Per Indoor
Connected Indoor Units Unit
2.0kg
~80
+ 81~160 2.5kg
161~330 3.0kg
331~390 3.5kg
391~480 4.5kg
481~630 5.0kg
631~710 6.0kg
711~800 8.0kg
801~890 9.0kg
891~1070 10.0kg
1071~1250 12.0kg
14.0kg
1251~
15