Precautions When Reusing Existing R22 Refrigerant Pipes - Mitsubishi Mr.Slim PUHZ-SHW80VHA Service Manual

3-3. PRECAUTIONS WHEN REUSING EXISTING R22 REFRIGERANT PIPES

(1) Flowchart
The existing pipe thickness meets speci-
fications and the pipes are not damaged.
Check if existing air conditioner can operate.
Existing air conditioner can
operate.
Perform cooling operation
for about 30 minutes and
then do a pump down work.
Disconnect existing air con-
ditioner from piping.
Existing pipes can be reused.
Connect a new air conditioner.
Connecting a new air conditioner
1 Flaring work should be done so that flare meets the dimension for R410A.
Use flare nut provided with indoor and outdoor unit.
2 When using gas piping of [19.05mm for SHW112, 140.
Make sure that DIP SW8-1 on outdoor unit controller board is set to ON. This is to keep
the pressure on pipes within permissible range.
3
Make sure that DIP SW8-1 on outdoor unit controller board is set to ON. This is to
prevent oil flow ratio from lowering due to the decrease in flowing refrigerant.
4
The pipes can be reused.
OCH526B
Measure the existing pipe thickness and check for damage.
Existing air conditioner
cannot operate.
Use a refrigerant recovery
equipment to recover the
refrigerant.
Note:
In case existing pipes were used
for gas or oil heat pump system,
be sure to clean the pipes.
5
The existing pipe thickness does not meet
specifications or the pipes are damaged.
Existing pipes cannot be
reused. Use new pipes.
SHW·HA