Refrigerant Circuit; Rmxs 112/140/160 D7V3B - Daikin Super Multi Plus D-Series Service Manual

Refrigerant Circuit

1. Refrigerant Circuit

1.1

RMXS 112/140/160 D7V3B

No. in
refrigerant
Symbol
system
diagram
A M1C Inverter compressor (INV)
M1F
D Inverter fan
M2F
Electronic expansion valve
E Y1E
(Main: EV1)
Electronic expansion valve
F Y2E
(Subcool: EV2)
G Y1S Solenoid valve (Hot gas: SVP) Used to prevent the low pressure from transient falling.
Solenoid valve (Receiver gas
J Y2S
discharging: SVG)
M Y3S Four way valve
N S1NPH High pressure sensor
O S1NPL Low pressure sensor
HP pressure switch (For INV
P S1PH
compressor)
S — Fusible plug
Pressure regulating valve 1
T —
(Receiver to discharge pipe)
1 R1T Thermistor (Outdoor air: Ta)
2 R2T Thermistor (Suction pipe: Ts)
Thermistor (INV discharge
3 R3T
pipe: Tdi)
Thermistor (Heat exchanger
4 R4T
deicer: Tb)
Thermistor (Subcooling heat
5 R5T
exchanger gas pipe: Tsh)
44
Name
Inverter compressor is operated on frequencies between 52 Hz and 190 Hz by using
the inverter.
25 steps
Since the system is of air heat exchanging type, the fan is operated at 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.
Pl control is applied to keep the outlet superheated degree of subcooling heat
exchanger constant.
Used to collect refrigerant to receiver.
Used to switch the operation mode between cooling and heating.
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.
In order to prevent the increase of pressure when abnormal heating is caused by fire
or others, the fusible part of the plug is molten at a temperature of 70 to 75°C to
release the pressure into the atmosphere.
This valve opens at a pressure of 2.0 to 2.7 MPa for prevention of pressure increase,
thus resulting in no damage of functional parts due to the increase of pressure in
transportation or storage.
Used to detect outdoor temperature, correct discharge pipe temperature, and others.
Used to detect suction pipe temperature, keep the suction superheated degree
constant in heating operation, and others.
Used to detect discharge pipe temperature, make the temperature protection control of
compressor, and others.
Used to detect liquid pipe temperature of air heat exchanger, determine defrosting
operation, and others.
Used to detect gas pipe temperature on the evaporation side of subcooling heat
exchanger, keep the superheated degree at the outlet of subcooling heat exchanger
constant, and others.
Major Function
SiEBE18-526
Refrigerant Circuit