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Refrigerant Circuit (Piping Diagrams)
SiME281906E
21
Part 2 Refrigerant Circuit
1.2 30/36 Class
Piping diagram: Indoor unit
Unit
No. in
piping
diagram
Electric
symbol
Name
Function
Indoor
unit
(1)
R1T
Suction air thermistor
Thermostat control, General frequency control
(2)
R2T
Indoor heat exchanger liquid
pipe thermistor
Compressor frequency control (Target Te), Freeze-up control
(3)
R3T
Indoor heat exchanger
middle thermistor
—
S1L
Float switch
When the water level reaches its upper limit, the float switch turns OFF.
Outdoor
unit
(4)
M1C
Compressor
Inverter drive unit varies compressor operating frequency to control
capacity and other factors.
(5)
Y1E
Electronic expansion valve Provides control to maintain optimum operating condition for high
efficiency.
(6)
R1T
Outdoor air thermistor
Used for startup condition control and for overall current protection
control. (Upper limit current depends on the outdoor air temperature.)
(7)
R2T
Discharge pipe thermistor
Used for discharge pipe temperature protection during compression
operation.
(8)
R3T
Suction pipe thermistor
Used for suction super heat control by electronic expansion valve.
(9)
R4T
Outdoor heat exchanger
liquid pipe thermistor
Used for calculation of outdoor heat exchanger subcooling during
cooling operation.
(10)
R5T
Outdoor heat exchanger
middle thermistor
Used for calculation of high pressure during cooling operation.
(Calculate Pc by detected temperature and R-32 refrigerant
characteristics.)
(11)
R7T
Power module thermistor
Used for calculation of IPM (intelligent power module) temperature.
(Calculate IPM temperature by detected radiation fin temperature.)
(12)
S1PH
High pressure switch
The switch is activated at high pressure of 4.15 MPa or more to stop
the compressor operation.
C: 3D119900A
R1T
(1)
R2T
(2)
R3T
(3)