13  REFRIGERANT PIPING WORK
For the refrigerant piping work, vacuum pump and refrigerant charge, the details shall be referred to Installation and Operation 
Manual of the outdoor unit.
13.1 PIPING MATERIALS
1  The tolerance of refrigerant piping length diers depending 
on the combination with the outdoor unit. The details shall be 
referred to Installation and Operation Manual of the outdoor 
unit.
2  Select the piping size from the following table.
Unit: mm
Model Gas piping Liquid piping
RPC-1.5FSR Ø12.7 (1/2) Ø6.35 (1/4)
RPC-2.0FSR Ø12.7 (1/2) Ø6.35 (1/4)
RPC-(2.5-6.0)FSR Ø15.88 (5/8) Ø9.52 (3/8)
3  Prepare eld-supplied copper pipes.
4  Select clean copper pipes. Make sure there is no dust and 
moisture inside.
5  As the new refrigerant (R410A) is adopted, the refrigerant 
oil has been also changed, which tends to be aected by 
foreign matters such as moisture, oxide lm, fat. Perform the 
installation work with care not to enter moisture, dust or old 
refrigerant into the refrigerant cycle, otherwise the parts such 
as expansion valve bite foreign matter and the operation 
may be unavailable.
6  Use a pipe cutter to avoid a grind swarf generation for the 
pipe cutting work. (Do not use a saw or a grind stone to cut 
pipes.) Blow the inside of the pipes with nitrogen or dry air, 
to remove any dust or foreign materials before connecting 
pipes.
Correct
Correct
Incorrect
Incorrect
Incorrect
Correct
Hole
Hole
When installing pipe through the wall, 
secure a cap at the end of the pipe.
Do not place the pipe directly on the 
ground.
Attach a cap or 
vinyl tape.
Attach a cap or 
vinyl tape.
Rain water  
can enter.
Attach a cap or vinyl bag 
with rubber band.
REFRIGERANT PIPING WORK
PMML0551 rev.4 - 07/2023 - A10762310A
17
EN