Mitsubishi Electric CITY MULTI PEFY-P22VMS-E-S Data Book page 301

3. Piping Design
3-3-2. PUMY-P-YKMC-C
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 below, 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.)
<Additional charge>
Calculation of refrigerant charge
Pipe size Pipe size
Liquid pipe Liquid pipe
+
ø6.35 ø9.52
(
(m) × 19.0 (g/m)
Included refrigerant amount when shipped from the factory
Included refrigerant amount
7.3 kg
Example:
PUMY-P250YKMC-C
P100
Outdoor model: P250
1: P100 A: ø9.52 [3/8"]/ø22.2 [7/8"]: 30 m
2: P50
3: P40
4: P32
The total length of each pipe size is as follows:
ø9.52 [3/8"]/ø22.2 [7/8"] A = 30 m
ø9.52 [3/8"]/ø15.88 [5/8"]: a = 15 m
ø6.35 [1/4"]/ø12.7 [1/2"]: b + c + d = 10 m + 10 m + 20 m = 40 m
The total capacity of connected indoor units is as follows:
P100 + P50 + P40 + P32 = P222
Therefore, the additional charge is as follows:
= (10 + 10 + 20) × 19.0
1000
= 6.1 kg
Pipe size
Liquid pipe
+
ø12.7
(m) × 92.0 (g/m)
m) × 50.0 (g/m)
A ( 30 m )
a ( 15 m)
b ( 10 m )
P50
a: ø9.52 [3/8"]/ø15.88 [5/8"] 15 m
b: ø6.35 [1/4"]/ø12.7 [1/2"] 10 m
c: ø6.35 [1/4"]/ø12.7 [1/2"] 10 m
d: ø6.35 [1/4"]/ø12.7 [1/2"] 20 m
50.0
+ (30+15) × + 3.0
1000
SYSTEM DESIGN
Total capacity of Amount for the
connected indoor units indoo runits
+
~P160 2.5 kg
P161 ~ P250 3.0 kg
P251 ~ 3.5 kg
d ( 20 m )
c ( 10 m)
P40
For these piping
lengths
C7-R Rev.
P32
4 - 24