Refrigerant Circuit; Rxyq72P, 96P, 120P - Daikin RXYQ96PYDN Service Manual

SiUS34-801A_b

2. Refrigerant Circuit

2.1

RXYQ72P, 96P, 120P

No. in
refrigerant
Symbol
system
diagram
1 M1C Inverter compressor (INV)
Standard compressor 1
2 M2C
(STD1)
4 M1F Inverter fan
Electronic expansion valve
6 Y1E
(Main: EVM)
Electronic expansion valve
7 Y3E
(Subcool: EVT)
Electronic expansion valve
8 Y2E
(Refrigerant charge EVJ)
9 Y6S
Solenoid valve (Main bypass SVE)
10 Y5S Solenoid valve (Hot gas: SVP) Prevents the low pressure from transient falling.
Solenoid valve (Refrigerant
11 Y4S
regulator liquid pipe SVL)
Solenoid valve (Refrigerant
12 Y1S regulator gas purging pipe
SVG)
Solenoid valve (Refrigerant
13 Y7S
regulator discharge pipe SVO)
Solenoid valve (Discharge
14 Y8S
pipe of refrigerant regulator)
4 way valve (Heat exchanger
15 Y3S
switch 20SA)
4 way valve (Dual pressure
16 Y2S
gas pipe switch 20SB)
17 S1NPH High pressure sensor
18 S2NPL Low pressure sensor
HP pressure switch (For INV
19 S1PH
compressor)
HP pressure switch (For STD
20 S2PH
compressor 1)
Pressure regulating valve
22 —
(Liquid pipe)
Pressure regulating valve
23 —
(Refrigerant regulator)
24 — Subcooling heat exchanger
25 — Refrigerant regulator
26 — Capillary tube
27 — Capillary tube
29 — Capillary tube
30 R1T Thermistor (Outdoor air: Ta)
31 R8T Thermistor (Suction pipe: TsA) Detects suction pipe temperature.
Thermistor (INV discharge
32 R31T
pipe: Tdi)
Thermistor (STD1 discharge
33 R32T
pipe: Tds1)
Thermistor (Heat exchanger
35 R4T
deicer: Tb)
Thermistor (Heat exchanger
36 R2T
gas pipe Tg)
Thermistor (Heat exchanger
37 R7T
liquid pipe Tf)
Thermistor (Subcooling heat
38 R5T
exchanger gas pipe: Tsh)
Thermistor (Subcooling heat
39 R6T
exchanger liquid pipe Tl)
40 R9T Thermistor (Liquid pipe Tsc)
VRVIII R-410A Heat Pump 60Hz
Name
Inverter compressor is operated on frequencies between 52Hz and 210Hz by using the
inverter, while Standard compressor is operated with commercial power supply only. The
number of operating steps is as follows when Inverter compressor is operated in
combination with Standard compressor.
Compressor operation steps : Refer to page 45~46.
Since the system is of the outdoor unit heat exchanging type, the fan is operated at 9-step
rotation speed by using the inverter.
While in heating operation, PI control is applied to keep the outlet superheated degree of
the outdoor unit heat exchanger constant.
PI control is applied to keep the outlet superheated degree of subcooling heat exchanger
constant.
Opens/closes refrigerant charge port.
Opens in cooling operation.
Collects refrigerant to the refrigerant regulator.
Collects refrigerant to the refrigerant regulator.
Discharges refrigerant from the refrigerant regulator.
Bypasses the high pressure gas to the refrigerant regulator.
Switches outdoor heat exchanger to evaporator or condenser.
Switches dual pressure gas pipe to high pressure or low pressure.
Detects high pressure.
Detects low pressure.
Functions when pressure increases to stop operation and avoid high pressure increase in
the event of a fault.
Used when pressure increases, to prevent any damage on components caused by
pressure increase in transport or storage.
Used when pressure increases, to prevent any damage on components caused by
pressure increase in transport or storage.
Applies subcooling to liquid refrigerant.
Surplus refrigerant is held according to the operation conditions.
Used to return the refrigerating oil separated through the oil separator to the INV
compressor.
Used to return the refrigerating oil separated through the oil separator to the STD1
compressor.
Used to discharge refrigerant from the refrigerant regulator.
Detects outdoor temperature, correct discharge pipe temperature, and others.
Detects discharge pipe temperature. Used for compressor temperature protection control.
Detects liquid pipe temperature of the outdoor unit heat exchanger. Used to make
judgments on defrosting operation.
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.
Detects temperature of liquid pipe between the the outdoor unit heat exchanger and main
electronic expansion valve. Used to make judgments on the recover or discharge
refrigerants to the refrigerant regulator.
Detects gas pipe temperature on the evaporation side of subcooling heat exchanger. Used
to exercise the constant control of superheated degree at the outlet of subcooled heat
exchanger.
Detects temperature of liquid pipe between the main expansion valve and subcooling heat
exchanger.
Detects temperature of liquid pipe between the liquid stop valve and subcooling heat
exchanger.
Major Function
Refrigerant Circuit
17