Refrigerant Piping System; Additional Refrigerant Charge; Calculation Of Additional Refrigerant Charge - Mitsubishi Electric PUHY-P-YMF-C Series Installation Manual

• Store the piping to be used during installation indoors and keep both
ends of the piping sealed until just before brazing.
- If dust, dirt, or water gets into the refrigerant cycle, the oil will deteriorate and
the compressor may fail.
• Do not use a charging cylinder. (For R407C models)
- Using a charging cylinder may cause the refrigerant to deteriorate.
• Do not use special detergents for washing piping.

8.2. Refrigerant piping system

Å Liquid line
Ç Total capacity of indoor units
‰ Downstream unit model total
Ì 4 branching header
¬ 10 branching header
Connection Example (PUHY-(P)400/500YMF-C)
[Fig.8.2.1] (P.3)
A Outdoor unit
B First branch
The first branch on the outdoor unit must be the CMY -Y202-F.
C Indoor unit
Note:
• The model total for downstream units shown in the table below is the
model total when viewed from Point A in the drawing above.
[Fig.8.2.2] (P.3)
A Outdoor unit
B First branch (Branch joint)
The first branch must be the CMY-Y202-F when the outdoor unit and header
branch are to be used.
C Branch joint
E Branch header
Note:
• Branch piping cannot be used again after the header branch.
• The model total for downstream units shown in the table below is the
model total when viewed from Point A in the drawing above.

9. Additional refrigerant charge

At the time of shipping, the outdoor unit is charged with the refrigerant. As this
charge does not include the amount needed for extended piping, additional charg-
ing for 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 pro-
vided on the outdoor unit.
9.1. Calculation of additional refrigerant
charge
[PUHY-(P)400/500YMF-C]
• Additional refrigerant charge
At the time of shipping, the outdoor unit PUHY-(P)400 is charged with 16 kg of
refrigerant and the PUHY-(P)500 is charged with 21 kg. As this charge does not
include the amount needed for extended piping, additional charging for each re-
frigerant 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.
•

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 to the right as guide to calculating the amount of additional
charging and charge the system according.
• 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 15.02 kg, round the
result up to 15.1 kg.
<Additional charge>
Liquid pipe size Liquid pipe size
total length of total length of
+ +
ø15.88 × 0.25 ø12.7 × 0.12
(m) × 0.25 (kg/m) (m) × 0.12 (kg/m)
<Example>
Indoor 1: 125 A: ø15.88 30 m
2: 100 B: ø12.7 10 m
3: 40 C: ø12.7 15 m
4: 32
5: 32
ı Gas line
Î Model number
Ï Branch kit model
Ó 7 branching header
D To downstream units
D Indoor unit
F Cap
Liquid pipe size Liquid pipe size
total length of total length of
+ α
+
ø9.52 × 0.06 ø6.35 × 0.024
(m) × 0.06 (kg/m) (m) × 0.024 (kg/m)
a: ø9.52 10 m
b: ø9.52 20 m
At the
c: ø6.35 10 m conditions
d: ø6.35 10 m below:
e: ø6.35 10 m
Connection Example (PUHY-(P)600/650/700/750YSMF-C)
[Fig.8.2.3] (P.4)
A Constant capacity unit
C First branch
E To downstream units
F Distributor (liquid), Distributor (gas) → Note2
G Oil balance pjpe (optional) 1 (for distribution within the unit)
H Distributor (gas) (optional)
J Gas line A
L Gas line B
N Gas line (main) C
P Indicates piping connection points
Note 1:
• The model total for downstream units shown in the table below is the
model total when viewed from Point A in the drawing above.
• With the exception of PUHY-(P)600YSMF-C, the first branch is always
CMY-Y302-F.
Note2:
• Because it is built into the variable capacity unit, B is used to carry liquid
only. Set the constant capacity unit and variable capacity unit in accord-
ance with the G dimension given in the figure above (G=0.01 m).
[Fig.8.2.4] (P.4)
A Constant capacity unit
C First branch (Branch joint)
E Indoor unit
G cap
H Distributor (liquid), Distributor (gas) → Note2
Note 1:
• The model total for downstream units shown in the table below is the
model total when viewed from Point A in the drawing above.
• With the exception of PUHY-(P)600YSMF-C, the first branch is always
CMY-Y302-F.
Note2:
• Because it is built into the variable capacity unit, B is used to carry liquid
only. Set the constant capacity unit and variable capacity unit in accord-
ance with the G dimension given in the figure above (G=0.01m).
The total length of each liquid line is as follows:
ø15.88: A = 30 m
ø12.7: B + C = 10 + 15 = 25 m
ø9.52: a + b = 10 + 20 = 30 m
ø6.35: c + d + e = 10 + 10 + 10 = 30 m
Therefore,
<Calculation example>
Additional
refrigerant charge = 30 × 0.25 + 25 × 0.12 + 30 × 0.06 + 30 × 0.024 + 2.0 = 15.1 kg
Value of α
Total capacity of connecting indoor units
to Model 80
Models 81 to 160
Models 161 to 330
Models 331 to 480
Models 481 or more
[PUHY-(P)600/650/700/750YSMF-C]
Variable capacity unit
(P)400 (P)500
16 21
• Additional refrigerant charge
The outdoor unit is charged with refrigerant at the time of shipping according to the
chart above. As this charge does not include the amount needed for extended
piping, additional charging for 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.
• 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 to the right as guide to calculating the amount of additional
charging and charge the system according.
• 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 20.03 kg, round the
result up to 20.1 kg.
• If the total amount of refrigerant including the amount of refrigerant sealed in
the outdoor unit when shipped from the factor plus additional refrigerant for
extension piping exceeds 73 kg, use 73 kg as the total amount of refrigerant.
Amount of refrigerant when shipped from factory + added refrigerant = 73 kg.
B Variable capacity unit
D Indoor unit
I Distributor (liquid) (optional)
K Liquid line A
M Liquid line B
O Liquid line (main) C
B Variable capacity unit
D Branch joint
F Branch header
α
1.0 kg
1.5 kg
2.0 kg
2.5 kg
3.0 kg
(kg)
Constant capacity unit
(P)200 (P)250
6.5 8.5
13