9. Refrigerant and water piping
TCGB0075 rev.0 - 11/2012
102
9.1.5 Pump down of refrigerant
1st cycle (R410A)
C A U T I O N
•
To pump down the refrigerant of the R410A cycle (1st cycle) it must be done through the outdoor unit. Refer to
the outdoor unit
Installation and operation manual
for the procedure.
•
To pump down the R410A refrigerant from the indoor unit, supply power to it.
•
In case outdoor unit test run failure (compressor failure, etc.), switch the DSW1-2 ON of indoor unit PCB1.
Thereby the indoor unit SV1 and SV2 open and allow the R410A refrigerant inside the indoor unit to flow to be
collected from the outdoor unit side. Switch the DSW1-2 OFF when finishing the procedure.
2nd cycle (R134a)
C A U T I O N
The 2nd cycle (R134a) connections are factory installed and refrigerant charged so no vacuum or pumping down
work is needed.
9.1.6 Refrigerant check joints
1st cycle (R410A) Outdoor unit
2nd cycle (R134a) Indoor unit
B
Compressor
(Front view)
A
C
B
Heat exchangers
Hydraulic circuit
(Front side)
(Right side)
C
A
Part name
Function
Part name
Function
Check joint for gas stop valve “A”
High pressure
Check joint for piping “A”
High pressure or vacuum
Check joint for piping “B”
Exclusive for vacuum and
pump down refrigerant
Check joint for piping “B”
Vacuum and pump down refri-
gerant
Check joint for liquid stop valve “C”
Low pressure
Check joint for piping “C”
Low pressure or vacuum