Refrigerant Circuit; Rqyq140 · 180Py1, Rqeq140 ~ 212Py1; Refrigerant Circuit Part - Daikin RQYQ140-180PY1 Service Manual

Refrigerant Circuit

1. Refrigerant Circuit

1.1 RQYQ140 · 180PY1, RQEQ140 ~ 212PY1
No. in
refrigerant
Symbol
system
diagram
(1) M1C Inverter compressor (INV.)
(2) M1F Inverter fan
Electronic expansion valve
(3) Y1E
(Main)
Electronic expansion valve
(4) Y2E
(Refrigerant charge)
Electronic expansion valve
(5) Y3E
(Subcooling)
Solenoid valve (Refrigerant
(6) Y1S
regulator hot gas)
Solenoid valve (Refrigerant
(7) Y2S
regulator liquid pipe)
Solenoid valve (Refrigerant
(8) Y3S
regulator gas vent pipe)
(9) Y4S Solenoid valve (Hot gas)
Solenoid valve (Circuit of oil
(10) Y5S
return)
Four way valve (Heat
(11) Y6S
exchanger)
Four way valve (Dual
(12) Y7S
pressure gas pipe)
(13) Y8S Four way valve (Mixing unit)
Solenoid valve (Mixing unit
(14) Y9S
inlet)
(15) R1T Thermistor (Outdoor air: Ta)
(16) R2T Thermistor (Discharge pipe)
Thermistor (Heat exchanger
(17) R3T
liquid pipe)
Thermistor (Heat exchanger
(18) R4T
gas pipe)
(19) R5T Thermistor (Suction pipe)
Thermistor (Heat exchanger
(20) R6T
deicer)
Thermistor (Subcooling heat
(21) R7T
exchanger gas pipe)
Thermistor (Subcooling heat
(22) R8T
exchanger liquid pipe)
(23) R9T Thermistor (Liquid pipe)
(25) S1NPH High pressure sensor
(26) S1NPL Low pressure sensor
High pressure switch (For
(27) S1PH
INV.)
Pressure regulating valve
(28) —
(Liquid pipe)
(29) — Subcooling heat exchanger
(30) — Capillary tube
19
Name
Inverter compressor is operated on frequencies 52Hz to 210Hz (180 class: 248Hz, 212
class: 266Hz) by using the inverter. The number of operating steps is 20. (180 class:
23 steps, 212 class: 27 steps)
Because the system is an air heat exchange type, the fan is operated 8-step rotation
speed by using the inverter.
While in heating operation, PI control is applied to keep the outlet superheated degree
of air heat exchanger constant.
This is used to charge refrigerant and discharge refrigerant from the refrigerant
regulator.
PI control is applied to keep the outlet superheated degree of subcooling heat
exchanger constant.
Used to charge refrigerant and discharge refrigerant from the refrigerant regulator.
Used to collect refrigerant to the refrigerant regulator.
Used to collect refrigerant to the refrigerant regulator.
Used to prevent the low pressure from transient falling.
Used to adjust the amount of oil in the mixing unit.
Used to switch the operation mode between cooling and heating.
Used to switch dual pressure gas pipe to high pressure or low pressure.
Use to adjust the amount of refrigeration oil and clean pipes during check operation.
Use to adjust the amount of refrigeration oil and clean pipes during check operation.
Use to prevent refrigerant from flowing into the mixing unit during normal operation.
Used to detect outdoor temperature, correct discharge pipe temperature and others.
Used to detect discharge pipe temperature. Used for compressor temperature
protection control.
This detects temperature of liquid pipe between the air heat exchanger and main
electronic expansion valve. Used to make judgements on the recover or discharge
refrigerants to the refrigerant regulator.
This detects temperature of gas pipe for air heat exchanger. Used to exercise the
constant control of superheated degree when an evaporator is used for outdoor unit
heat exchanging.
Used to detect suction pipe temperature.
Used to detect liquid pipe temperature of air heat exchanger. Used to make
judgements on defrosting operation.
This detects temperature of gas pipe on the evaporation side of subcooling heat
exchanger. Used to exercise the constant control of superheated degree at the outlet
of subcooled heat exchanger.
This detects temperature of liquid pipe between the main electronic expansion valve
and subcooling heat exchanger.
This detects temperature of liquid pipe.
Used to detect high pressure.
Used to detect low pressure.
In order to prevent the increase of high pressure when a malfunction occurs, this
switch is activated at high pressure of 4.0 MPa or more to stop the compressor
operation.
Open at 3.3 MPa or more to avoid pressure increase to prevent damage to functional
parts by the pressure increase and to protect the field piping during transportation,
storage and operation of the equipment.
Apply subcooling to liquid refrigerant.
Used to return the refrigerating oil separated through the oil separator to the INV.
compressor.
Major Function
SiBE341001
Refrigerant Circuit