Daikin REYQ8-48PY1B, Service Manual

Page: 78 / 477

Refrigerant Circuit SiBE37-701_B
67 Refrigerant Circuit
1.5 REMQ14P, 16P (Multi 14, 16HP)
No. in
refrigerant
system
diagram
Symbol Name Major Function
1 M1C Inverter compressor (INV) 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 111~115.
2 M2C Standard compressor 1 (STD1)
3 M3C Standard compressor 2 (STD2)
4 M1F Inverter fan
Because the system is an air heat exchange type, the fan is operated at 9-step rotation
speed by using the inverter.
5 M2F Inverter fan
Because the system is an air heat exchange type, the fan is operated at 9-step rotation
speed by using the inverter.
6 Y1E
Electronic expansion valve
(Main: EVM) While in heating operation, PI control is applied to keep the outlet superheated degree
of air heat exchanger constant.
7 Y3E
Electronic expansion valve
(Subcooling: EVT) PI control is applied to keep the outlet superheated degree of subcooling heat
exchanger constant.
8 Y2E
Electronic expansion valve
(Refrigerant charge: EVJ)
This is used to open/close refrigerant charge port.
9 Y6S Solenoid valve (Main bypass: SVE) This opens in cooling operation.
10 Y5S Solenoid valve (Hot gas: SVP) Used to prevent the low pressure from transient falling.
11 Y4S
Solenoid valve (Refrigerant
regulator liquid pipe: SVL)
This is used to collect refrigerant to the refrigerant regulator.
12 Y1S
Solenoid valve (Refrigerant
regulator gas vent pipe: SVG)
This is used to collect refrigerant to the refrigerant regulator.
13 Y7S
Solenoid valve (Refrigerant
regulator discharge pipe: SVO)
This is used to discharge refrigerant from the refrigerant regulator.
14 Y8S
Solenoid valve (Discharge
pipe of refrigerant regulator)
Bypass the high pressure gas to the refrigerant regulator.
15 Y3S
Four way valve (Heat
exchanger switch: 20SA)
This is used to switch outdoor heat exchanger to evaporator or condenser.
16 Y2S
Four way valve (Dual pressure
gas pipe switch: 20SB)
This is used to switch dual pressure gas pipe to high pressure or low pressure.
17 S1NPH High pressure sensor Used to detect high pressure.
18 S2NPL Low pressure sensor Used to detect low pressure.
19 S1PH
High pressure switch (For INV
compressor)
This functions when pressure increases to stop operation and avoid high pressure
increase in the fault operation.
20 S2PH
High pressure switch (For
STD compressor 1)
21 S3PH
High pressure switch (For
STD compressor 2)
22 —
Pressure regulating valve
(Liquid pipe) This is used when pressure increases, to prevent any damage on components caused
by pressure increase in transport or storage.
23 —
Pressure regulating valve
(Refrigerant regulator) This is used when pressure increases, to prevent any damage on components caused
by pressure increase in transport or storage.
24 — Subcooling heat exchanger Apply subcooling to liquid refrigerant.
25 — Refrigerant regulator Surplus refrigerant is held according to the operation conditions.
26 — Capillary tube
Used to return the refrigerating oil separated through the oil separator to the INV compressor.
27 — Capillary tube
Used to return the refrigerating oil separated through the oil separator to the STD1 compressor.
28 — Capillary tube
Used to return the refrigerating oil separated through the oil separator to the STD2 compressor.
29 — Capillary tube This is used to discharge refrigerant from the refrigerant regulator.
30 R1T Thermistor (Outdoor air: Ta) Used to detect outdoor temperature, correct discharge pipe temperature and others.
31 R8T Thermistor (Suction pipe: TsA) Used to detect suction pipe temperature.
32 R31T Thermistor (INV discharge pipe: Tdi)
Used to detect discharge pipe temperature. Used for compressor temperature
protection control.
33 R32T Thermistor (STD1 discharge pipe: Tds1)
34 R33T Thermistor (STD2 discharge pipe: Tds2)
35 R4T
Thermistor (Heat exchanger
deicer: Tb) Used to detect liquid pipe temperature of air heat exchanger. Used to make
judgements on defrosting operation.
36 R2T
Thermistor (Heat exchanger
gas pipe: Tg)
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.
37 R7T
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 judgements on the recover or discharge
refrigerants to the refrigerant regulator.
38 R5T
Thermistor (Subcooling heat
exchanger gas pipe: Tsh)
This detects temperature of gas pipe on the evaporator side for the subcooling heat
exchanger. Used to exercise the constant control of superheated degree at the outlet
of subcooled heat exchanger.
39 R6T
Thermistor (Subcooling heat
exchanger liquid pipe: Tl) This detects temperature of liquid pipe between the main expansion valve and
subcooling heat exchanger.
40 R9T Thermistor (Liquid pipe: Tsc)
This detects temperature of liquid pipe between the liquid stop valve and subcooling
heat exchanger.