Additional Refrigerant Charge; Calculation Of Additional Refrigerant Charge - Mitsubishi Electric CITY MULTI PURY-P-THMU-A (-BS) Manuel D'installation

<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.
F
H
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 [19-11/16 in] or more
K

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
charge Total length of
=
ø28.58 mm [1-1/8 in]
(m) × 0.36 (kg/m)
(kg) [oz]
(ft) × 3.88 (oz/ft)
Liquid Piping Size Liquid Piping Size
Total length of Total length of
+ ø15.88 mm [5/8 in] + ø12.7 mm [1/2 in]
(m) × 0.2 (kg/m) (m) × 0.12 (kg/m)
(ft) × 2.16 (oz/ft) (ft) × 1.30 (oz/ft)
BC controller
Total Outdoor Unit
(Standard/Main)
Model Name
+ Per Unit
P72 3.0 kg [106 oz]
P96
4.5 kg [160 oz]
P120
P144 6.0 kg [212 oz]
P168 7.5 kg [265 oz]
P192
P216 9.0 kg [318 oz]
P240
G
I
J
K
Twinning pipe (high-pressure side)
G
High-pressure
pipe size pipe size
Total length of
+
ø22.2 mm [7/8 in]
(m) × 0.23 (kg/m)
(ft) × 2.48 (oz/ft)
Liquid Piping Size
Total length of
+ ø9.52 mm [3/8 in]
(m) × 0.06 (kg/m)
(ft) × 0.65 (oz/ft)
BC controller
(Sub) Total Units
+
1
2
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 [4 oz], round up
to the next 0.1 kg [4 oz]. For example, if the result of the calculation was
27.73 kg [979 oz], round the result up to 27.8 kg [981 oz].
High-pressure High-pressure
pipe size
Total length of Total length of
+ +
ø19.05 mm [3/4 in] ø15.88 mm [5/8 in]
(m) × 0.16 (kg/m) (m) × 0.11 (kg/m)
(ft) × 1.73 (oz/ft) (ft) × 1.19 (oz/ft)
Liquid Piping Size
Total length of
+ ø6.35 mm [1/4 in]
(m) × 0.024 (kg/m)
(ft) × 0.26 (oz/ft)
BC controller Total Capacity of
(Sub) Per Unit Connected Indoor Units
+
1.0 kg [36 oz] Models
2.0 kg [71 oz] Models 28 ~ 54
Models 55 ~ 126
Models 127 ~ 144
Models 145 ~ 180
Models 181 ~ 234
Models 235 ~ 273
Models 274 ~ 307
Models 308 ~ 342
Models 343 ~ 411
Models 412 ~
pipe size
Per Indoor Unit
~ 27 2.0 kg [71 oz]
2.5 kg [89 oz]
3.0 kg [106 oz]
3.5 kg [124 oz]
4.5 kg [159 oz]
5.0 kg [177 oz]
6.0 kg [212 oz]
8.0 kg [283 oz]
9.0 kg [318 oz]
10.0 kg [353 oz]
12.0 kg [424 oz]
11