Refrigerant Circuit; Outdoor Unit; Refrigerant Circuit Part - Daikin Aurora Series Service Manual

Refrigerant Circuit

1. Refrigerant Circuit

1.1

Outdoor Unit

No. in
Electric
piping
symbol
diagram
(1) M1C Inverter compressor
M1F
(2) Inverter fan
M2F
Electronic expansion valve
(3) Y1E
(Heat exchanger upper)
Electronic expansion valve
(4) Y2E
(Subcooling heat exchanger)
Electronic expansion valve
(5) Y3E
(Heat exchanger lower)
Electronic expansion valve
(6) Y4E
(Subcooling injection)
Electronic expansion valve
(7) Y5E
(Refrigerant cooling)
Electronic expansion valve
(8) Y6E
(Leak detection)
Electronic expansion valve
(9) Y7E
(Receiver gas purge)
Solenoid valve (Oil separator
(10) Y1S
oil return)
Solenoid valve
(11) Y2S
(Hot gas bypass)
(12) Y3S Solenoid valve (Liquid shutoff) Used to shut off liquid refrigerant flow to the receiver.
Four way valve (HP/LP gas
(13) Y4S
pipe)
Four way valve
(14) Y5S
(Heat exchanger lower)
Four way valve
(15) Y6S
(Heat exchanger upper)
Solenoid valve
(16) Y7S
(Accumulator oil return)
(17) S1NPH High pressure sensor
(18) S1NPL Low pressure sensor
High pressure switch
(19) S1PH
(For inverter compressor)
Pressure regulating valve
(20) —
(Liquid pipe)
(21) — Subcooling heat exchanger
(22) — Capillary tube
(23) R1T Thermistor (Outdoor air)
(24) R21T Thermistor (M1C discharge)
(25) R3T Thermistor (Receiver inlet)
Thermistor (Heat exchanger
(26) R4T
liquid upper)
Thermistor (Heat exchanger
(27) R5T
liquid lower)
(28) R6T Thermistor (Subcooling gas)
(29) R7T Thermistor (Subcooling liquid) This detects temperature of liquid pipe for subcooling heat exchanger.
Thermistor (Heat exchanger
(30) R8T
gas upper)
Thermistor (Heat exchanger
(31) R9T
gas lower)
(32) R10T Thermistor (Suction)
(33) R11T Thermistor (Deicer)
Thermistor (Compressor
(34) R12T
suction)
Thermistor
(35) R13T
(Receiver gas purge)
(36) R14T Thermistor (M1C body)
(37) R15T Thermistor (Leak detection)
Thermistor
(38) R16T
(Subcooling injection)
11
Name
Inverter compressor is operated on frequencies between 15 rps to 140 rps by using the
inverter. Refer to page 50, 51.
Because the system is an air heat exchange type, the fan is operated at 53 steps of
rotation speed by using the inverter. Refer to page 53.
While in heating, PI control is applied to keep the outlet superheated degree of air heat
exchanger constant.
PI control is applied to keep the outlet superheated degree of subcooling heat exchanger
constant.
While in heating, PI control is applied to keep the outlet superheated degree of air heat
exchanger constant.
Used to control compressor injection.
Used to control the refrigerant amount to cool the diode bridge and power module of the
inverter PCB.
Used to detect refrigerant leakage.
Used to collect the refrigerant to receiver.
Used to return oil from the oil separator to the compressor.
Used to flow discharge gas to the compressor inlet.
Used to switch dual pressure gas pipe to high pressure or low pressure.
Used to switch outdoor unit heat exchanger to evaporator or condenser.
Used to return oil from the accumulator to the compressor.
Used to detect the high pressure.
Used to detect the low pressure.
This functions when pressure increases to stop operation and avoid high pressure
increase in the fault operation.
This is used when pressure increases, to prevent any damage on components caused by
pressure increase in transport or storage.
Apply subcooling to liquid refrigerant.
Used to return the refrigerating oil separated through the oil separator to the inverter
compressor.
Used to detect outdoor air temperature, correct discharge pipe temperature and others.
Used to detect discharge pipe temperature.
Used to detect liquid pipe temperature of receiver inlet.
This detects temperature of liquid pipe for air heat exchanger.
This detects temperature of gas pipe for subcooling heat exchanger.
This detects temperature of gas pipe for air heat exchanger.
Used to detect suction pipe temperature.
Used to detect liquid pipe temperature of air heat exchanger. Used to make judgements
on defrost operation.
Used to detect suction pipe temperature of compressor.
Used to detect gas pipe temperature of receiver gas purge piping.
Detects compressor surface temperature, this switch is activated at surface temperature
of 120°C (248°F) or more to stop the compressor.
The thermistor detects refrigerant leakage.
Used to control subcooling injection.
Function
SiUS341802E
Refrigerant Circuit