4. Installing the refrigerant piping
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.
en
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.
<Limits of refrigerant piping installation>
ZM71
: A+B+C
* "D" is for triple.
5. Drainage piping work
Outdoor unit drainage pipe connection
When drain piping is necessary, use the drain socket or the drain pan (option).
Drain socket
Drain pan
10
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 use new pipes.
Test run
* Refer to 7.2.
A Indoor unit
B Outdoor unit
C Multi distribution pipe (option)
D Height difference (Indoor unit-
Outdoor unit) Max. 30 m
E Height difference (Indoor unit-
Indoor unit) Max. 1 m
A: Main piping
B, C, D: Branch piping
{ 55 m
Fig. 4-7
ZM71
PAC-SH71DS-E
PAC-SG64DP-E
The existing pipe thickness does not meet
specifications or the pipes are damaged.
The existing pipes cannot be reused.
Use new pipes.
4.8. For twin/triple combination (Fig. 4-7)
• When this unit is used as a FREE COMPO MULTI unit, install the refrigerant
piping with the restrictions indicated in the drawing on the left. In addition, if the
restrictions are going to be exceeded, or if there are going to be combinations of
indoor and outdoor units, refer to installation instructions for the indoor unit for
details about the installation.
Permissible total
Outdoor unit
piping length
A+B+C+D
ZM71
55 m and less
Outdoor unit
│B-C│ or │B-D│or │C-D│
ZM71
8 m and less
A+B or A+C
Charge-less
or
piping length
A+D
A+B+C+D
–
30 m and less
No. of bends
Within 15