Mitsubishi Electric PUHZ-RP-HA4 Installation Manual page 8

4. Installing the refrigerant piping
When length exceeds 70 m
When the total length of the piping exceeds 70 m, calculate the amount of additional charge based on the following requirements.
Note: If the calculation produces a negative number (i.e. a "minus" charge), of if calculation results in an amount that is less than the "Additional charage amount for 70 m",
perform the additional charge using the amount shown in "Additional charge amount for 70 m".
Main piping:
Liquid line size
Amount of additional
ø12.7 overall length ×
charge
=
0.11
(kg) (m) × 0.11 (kg/m)
RP200 3.6 kg
Additional charge amount
for 70 meters
RP250 4.8 kg
Fig. 4-9
Maximum pipe length (RP200·RP250)
O.D.
Liquid
pipe
Thick-
(mm)
ness
Gas O.D.
19.05
pipe
Thick-
t1.0
(mm)
ness
RP200
20m
[20m] [30m]
20m
RP250
[20m] [30m]
Note : Be sure to use hard (tempered) one for pipe over 22.2.
<Marks in the table above>
: It can be used.
: Cooling capacity is lowered.
: Additional refrigerant charge is required when
the pipe length exceeds 20m.
The maximum pipe length
120m
Charge-less pipe length
[30m]
RP200, 250
Additional refrigerant amount when the liquid pipe of the larger diameter is used.
1:1 system
Liquid pipe When the pipe length exceeds 20 m
[15.88
Additional refrigerant amount
* w (g) 0 : Additional charge is not necessary.
Simultaneous twin/triple/quadruple system
When the pipe length (main piping and branch piping) exceeds 20 m
Additional refrigerant amount w (g) =(180 × L1)+(120 × L2) +(90 × L3)+(30 × L4) - 3000
L1 : [15.88 liquid pipe length (m)
L3 : [9.52 liquid pipe length (m)
* w (g) 0 : Additional charge is not necessary.
8
Main piping:
Liquid line size
ø9.52 overall length ×
+
0.09 (Gas line: ø25.4)
(m) × 0.09 (kg/m)
Indoor unit
Outdoor unit
Main piping
Branch piping
Multi distribution
pipe (option)
9.52
t0.8
25.4 28.58 19.05
22.2
t1.0 t1.0 t1.0
t1.0
Standard size
50m 120m 120m 20m
[30m] [30m] [20m]
120m 120m 20m
50m
[30m] [30m] [20m]
w (g) =180 × Pipe length (m) - 3000
L2 : [12.7 liquid pipe length (m)
L4 : [6.35 liquid pipe length (m)
Branch piping: Branch piping:
Liquid line size Liquid line size
ø9.52 overall length × ø6.35 overall length ×
+ +
0.06 (Gas line: ø15.88) 0.02
(m) × 0.06 (kg/m)
Outdoor unit : RP250 A: ø12.7 ... 65 m
Indoor unit 1 : RP71 B: ø9.52 ... 5 m
Indoor unit 2 : RP71 C: ø9.52 ... 5 m
Indoor unit 3 : RP71 D: ø9.52 ... 5 m
Main piping ø12.7 is A = 65 m
Branch piping ø9.52 is B + C + D = 15 m
Therefore, the amount of additional charge is: 65 × 0.12 + 15 × 0.06 - 3.6 = 5.1(kg)
(Fractions are rounded up)
12.7
t0.8
22.2 25.4 28.58
t1.0 t1.0 t1.0
50m 120m 120m 50m
[30m] [30m] [30m] [20m]
Standard size
50m 120m 120m 50m
[30m] [30m] [30m] [20m]
–
3.6 (kg)
(m) × 0.02 (kg/m)
15.88
t1.0
22.2 25.4 28.58 31.75
t1.0 t1.0 t1.0 t1.1
50m 50m 50m
[20m] [20m] [20m]
50m 50m 50m
[20m] [20m] [20m]