Mitsubishi Electric PUHZ-HRP-HA2 Installation Manual page 8

4. Installing the refrigerant piping
When length exceeds 50 m for twin / triple / quadruple combination (Only HRP200)
When the total length of the piping exceeds 50 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 50 m",
perform the additional charge using the amount shown in "Additional charge amount for 50 m".
Main piping:
Liquid line size
Amount of additional
ø12.7 overall length ×
charge
=
0.17
(kg) (m) × 0.17 (kg/m)
Additional charge amount
1.8 kg
for 50 meters
Fig. 4-9
4.7. Precautions when reusing existing R22 refrigerant pipes
• Refer to the flowchart below to determine if the existing pipes can be used and if it is necessary to use a filter dryer.
• If the diameter of the existing pipes is different from the specified diameter, refer to technological data materials to confirm if the pipes can be used.
The existing pipe thickness meets specifica-
tions and the pipes are not damaged.
▼
Check if the existing air conditioner can operate.
▼
After operating the cooling system for about 30
minutes, do a pump down work.
▼
Disconnect the existing air conditioner from the
pipes.
▼
Attach the new air conditioner
▼
Perform the airtight test, vacuum air purging,
additional refrigerant charging (if necessary),
and gas leak check.
▼
Test run
* Refer to 7.2.
8
Main piping:
Branch piping:
Liquid line size
Liquid line size
ø9.52 overall length ×
ø9.52 overall length ×
+ +
0.14 (Gas line: ø25.4)
0.05 (Gas line: ø15.88)
(m) × 0.14 (kg/m) (m) × 0.05 (kg/m)
Outdoor unit : HRP200 A: ø9.52 ... 65 m
Indoor unit
Indoor unit 1 : RP60
Outdoor unit
Indoor unit 2 : RP60
Main piping
Indoor unit 3 : RP60
Branch piping
Multi distribution
Main piping ø9.52 is A = 65 m
pipe (option)
Branch piping ø9.52 is B + C + D = 15 m
Therefore, the amount of additional charge is: 65 × 0.14 + 15 × 0.05 - 4.3 = 5.6 (kg)
(Fractions are rounded up)
Measure the existing pipe thickness and
check for damage.
* If the existing air conditioner cannot operate, use
a refrigerant recovery device to collect the refrigerant.
* In case existing pipes were used for gas or oil
heat pump systems, be sure to clean the pipes.
Branch piping:
Liquid line size
ø6.35 overall length ×
+
0.02
(m) × 0.02 (kg/m)
B: ø9.52 ... 5 m
C: ø9.52 ... 5 m
D: ø9.52 ... 5 m
The existing pipe thickness does not meet
specifications or the pipes are damaged.
▼
The existing pipes cannot be reused.
Use new pipes.
–
4.3 (kg)