Toshiba RAS-24N3KCV1 Installation Manual page 18

Are there scratches or dents on the existing pipes?
Is it possible to operate the existing air conditioner?
• After the existing air conditioner is operated in cooling mode
for approx. 30 minutes or longer,* recover the refrigerant.
• For cleaning the pipes and recovering oil
• Refrigerant recovery: Pump down method
• Remove the existing air conditioner from the piping and carry
out fl ushing (nitrogen pressure 0.5 MPa) to remove any
remains inside of the pipe.
Note In case of twin pipes, also be sure to fl ush the branching
pipe.
Was largely discolored oil or a large quantity of remains
discharged? (When the oil deteriorates, the color of the oil
changes to a muddy or black color.)
Connect the indoor/outdoor units to the existing pipe.
• Use a fl are nut attached to the main unit for the indoor/outdoor
units. (Do not use the fl are nut of the existing pipe.)
• Re-machine the fl are machining size to size for R410A.
In case that a gas pipe ∅19 mm or bigger is used for the outdoor
unit of (3 HP): (Our R410A model 3 to 5 HP gas pipe size is
∅15.9 mm)
t Turn the existing pipe switch on the cycle control PC board
of the outdoor unit to ON side. At shipment from factory
t
OFF ON for existing pipe (Refer to the table below.) (Be
sure to set the contents in the table below in order to restrict
the refrigerating cycle pressure of the equipment in the pipe
standard.)
Existing pipe SW
Bit 3 of SW802 t ON
3 HP
• (Airtight test), Vacuum dry, Refrigerant charge, Gas leak check
NO
YES
NO
Switch
Trial run
YES
Existing pipes: Cannot be used.
• Use new pipes.
NO
Nitrogen gas pressure 0.5 MPa
(If there is discharge of remains, it is judged that a large
quantity of remains are present.)
YES
Clean the pipes or use new pipes.
Piping necessary to change the fl are nut/
machining size due to pipe compression
1) Flare nut width: H
Copper
pipe outer
diameter
For R410A
For R22
2) Flare machining size: A
Copper
pipe outer
diameter
For R410A
For R22
Becomes a little larger for R410A
Do not apply refrigerator oil to the fl are surface.
16
∅6.4 ∅9.5 ∅12.7 ∅15.9
17 22 26 29
Same as above 24 27
∅6.4 ∅9.5 ∅12.7 ∅15.9
9.1 13.2 16.6 19.7
9.0 13.0 16.2 19.4
(mm)
∅19.0
36
Same
as
above
(mm)
∅19.0
24.0
23.3