SiME332106E
Refrigerant Circuit (Piping Diagrams)
Part 2 Refrigerant Circuit
15
1. Refrigerant Circuit (Piping Diagrams)
1.1 Outdoor Unit
No. in
piping
diagram
Electric
symbol
Name
Function
(1)
M1C
Compressor motor
Compressor is operated in multi-steps according to Te.
(2)
M1F
Fan motor
The fan rotation speed is varied by using the inverter.
(3)
Y1E
Electronic expansion
valve (Main)
Fully open during cooling operation.
(4)
Y2E
Electronic expansion
valve (Injection)
PI control is applied to keep the outlet superheating degree of subcooling heat
exchanger constant.
(5)
Y3E
Electronic expansion
valve (Refrigerant jacket)
Used in heating operation to control inverter fin temperature by adjusting the
refrigerant flow.
(6)
Y4E
Electronic expansion
valve (Refrigerant auto
charge)
Used to control refrigerant charging speed during refrigerant auto charge
operation and to stop refrigerant charge automatically.
(7)
Y1S
Solenoid valve (Four way
valve
Used to switch the operation mode between cooling and heating.
(8)
S1NPH
High pressure sensor
Used to detect high pressure.
(9)
S1NPL
Low pressure sensor
Used to detect low pressure.
(10)
S1PH
High pressure switch
In order to prevent the increase of high pressure when an error occurs, this switch
is activated at high pressure of 4.0 MPa or more to stop the compressor
operation.
(11)
—
Pressure regulating valve This valve opens at a pressure of 4.0 MPa for prevention of pressure increase,
thus resulting in no damage of functional parts due to the increase of pressure in
transportation or storage.
(12)
—
Double tube heat
exchanger (Subcooling
heat exchanger)
Used to subcool liquid refrigerant from the electronic expansion valve.
(13)
R1T
Thermistor
(Outdoor air: Ta)
Used to detect outdoor air temperature, correct discharge pipe temperature, and
for other purposes.
(14)
R21T
Thermistor
(Discharge pipe: Tdi1)
Used to detect discharge pipe temperature, make the temperature protection
control of compressor, and for other purposes.
(15)
R3T
Thermistor
(Suction pipe: Ts)
Used to detect suction pipe temperature, and for other purposes.
(16)
R4T
Thermistor
(Heat exchanger liquid
pipe: Tf)
This detects temperature of liquid pipe between the air heat exchanger and main
electronic expansion valve. Used to make judgments on the recover or discharge
refrigerants to the refrigerant regulator.
(17)
R5T
Thermistor
(Subcooling heat
exchanger liquid pipe:
Tsc)
This detects temperature of liquid pipe after subcooling heat exchanger.
(18)
R6T
Thermistor
(Subcooling heat
exchanger gas pipe: Tsh)
This detects temperature of gas pipe on the evaporation side of subcooling heat
exchanger. Used to exercise the constant control of superheating degree at the
outlet of subcooling heat exchanger.
(19)
R7T
Thermistor
(Heat exchanger deicer:
Tb)
Used to detect liquid pipe temperature of air heat exchanger.
