Mitsubishi Electric SMART MULTI MXZ-SM36NAM2-U1 Data Book page 80

11. PIPING DESIGN
11-3-3. MXZ-SM72/96/120TAM-U1
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 and total capacity of connected indoor units.
• Calculate the additional refrigerant charge using the procedure 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 6.01 kg, round up the charge to 6.1 kg.)
• The amount of additional refrigerant which is calculated from the total capacity of indoor units and the combination of extended pipes must
not be over 16.3 kg (575 oz).
Additional
refrigerant
charge
=
(kg)
[oz]
Example:
MXZ-
SM120TAM
P27
Additional
refrigerant
charge
=
(kg)
=
=
=
Additional
refrigerant
charge
[oz]
M-P0890
Pipe size Pipe size
Liquid pipe Liquid pipe
ø6.35 ø9.52
+
(m) × 0.019 (kg/m) (m) × 0.05 (kg/m)
{(ft) × 0.21 (oz/ft)} {(ft) × 0.55 (oz/ft)}
Outdoor: MXZ-SM120TAMl
Indoor 1: model P27
Indoor 2: model P27
Indoor 3: model P27
Indoor 4: model P27
Indoor 5: model P12
Total length of each liquid pipe is as follows
ø12.7 [1/4"] A = 30 m [98 ft.]
ø9.52 [3/8"] a + b + c + d = 10 + 10 + 10 + 15 = 45 m [148 ft.]
ø6.35 [1/4"] e = 15 m [49 ft.]
A ( 30 m [98 ft.] )
a ( 15 m [49 ft.] )
b ( 10 m [32 ft.] )
P27
Pipe size Pipe size
Liquid pipe Liquid pipe
ø6.35 ø9.52
+
(m) × 0.019 (kg/m) (m) × 0.05 (kg/m)
+
0.28 2.25
9.79
9.8 kg (round-up)
Pipe size Pipe size
Liquid pipe Liquid pipe
ø6.35 ø9.52
+
=
{(ft) × 0.21 (oz/ft)} {(ft) × 0.55 (oz/ft)}
+
= 79.75
10.29
= 346.06
= 347 [oz] (round-up)
Pipe size
Liquid pipe
ø12.7
+ +
(m) × 0.092 (kg/m)
{(ft) × 0.99 (oz/ft)}
A=ø12.7 [1/2"] 30 m [98 ft.]
a=ø9.52 [3/8"] 15 m [49 ft.]
b=ø9.52 [3/8"] 10 m [32 ft.]
c=ø9.52 [3/8"] 10 m [32 ft.]
d=ø9.52 [3/8"] 10 m [32 ft.]
e=ø6.35 [1/4"] 15 m [49 ft.]
e ( 15 m [49 ft.] )
d ( 10 m [32 ft.] )
c ( 10 m [32 ft.] )
P27
Pipe size
Liquid pipe
ø12.7 +
+
(m) × 0.092 (kg/m)
+
+
2.76
Pipe size
Liquid pipe
ø12.7
+
+
{(ft) × 0.99 (oz/ft)}
+
+
97.02
SMART MULTI
Total capacity
Amount for the
of connected
indoor units
indoor units
54 2.5 kg (88 oz)
3.0 kg (106 oz)
3.5 kg (123 oz)
4.0 kg (141 oz)
117 4.5 kg (159 oz)
5.0 kg (176 oz)
5.5 kg (194 oz)
6.1 kg (215 oz)
P27
P12
Total capacity
Amount for the
of connected
indoor units
indoor units
54 2.5 kg (88 oz)
3.0 kg (106 oz)
3.5 kg (123 oz)
4.0 kg (141 oz)
4.5 kg (159 oz)
5.0 kg (176 oz)
5.5 kg (194 oz)
6.1 kg (215 oz)
4.5
Total capacity
Amount for the
of connected
indoor units
indoor units
54 2.5 kg (88 oz)
3.0 kg (106 oz)
3.5 kg (123 oz)
4.0 kg (141 oz)
4.5 kg (159 oz)
5.0 kg (176 oz)
5.5 kg (194 oz)
6.1 kg (215 oz)
159
78