Refrigerant Circuit; Rxyq5Ma - Daikin RXYQ5-48MAY1 Service Manual

Refrigerant Circuit

1.

Refrigerant Circuit

1.1

RXYQ5MA

No. in
refrigerant
Symbol
system
diagram
A M1C Inverter compressor (INV)
D M1F Inverter fan
Electronic expansion valve
E Y1E
(Main: EV1)
G Y1S Solenoid valve (Hot gas: SVP) Used to prevent the low pressure from transient falling.
Solenoid valve (Receiver gas
J Y2S
discharging: SVG)
K Y4S Solenoid valve (Injection)
M Y3S 4-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)
V — Piping heat exchanger
W — Capillary tube
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 (Sub-cooling heat-
5 R5T
exchanger outlet)
50
Name
Inverter compressor is operated on frequencies between 52 Hz and 210 Hz by using
the inverter. The number of operating steps is as follows when Inverter compressor is
operated.
RXYQ5MA : 20 steps
Since the system is of air 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 air heat exchanger constant.
Used to collect refrigerant to receiver.
Used to cool the compressor by injecting refrigerant when the compressor discharge
temperature is high.
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 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 heat the gas refrigerant from the liquid receiver.
Used to return the refrigerating oil separated through the oil separator to the
compressor.
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 judge the refrigerant overcharge at the check operation.
Major Function
Si39-407
Refirgerant Circuit