Daikin VRV S RXMQ10ARY1, Service Manual

Page: 26 / 377

Refrigerant Circuit (Piping Diagrams) SiAF332111E
20 Part 2 Refrigerant Circuit
1.1.3 RXMQ6ARV1, RXMQ8ARY1
No. in
piping
diagram
Electric
symbol
Name Function
(1) M1C Compressor motor Inverter driven compressor is operated in multi-steps according to Te.
(2) M1F Fan motor The fan rotation speed is varied by using the inverter.
(3) Y2E
Electronic expansion
valve (Injection)
PI control is applied to keep the outlet superheating degree of subcooling heat
exchanger constant.
(4) Y4E
Electronic expansion
valve (Refrigerant auto
charge)
Used to control refrigerant charging speed during refrigerant auto charge
operation and to stop refrigerant charge automatically.
(5) S1NPH High pressure sensor Used to detect high pressure.
(6) S1NPL Low pressure sensor Used to detect low pressure.
(7) S1PH
High pressure switch In order to prevent the increase of high pressure when an error occurs, this switch
is activated at high pressure of 4.0 MPa or more to stop the compressor
operation.
(8) —
Pressure regulating valve This valve opens at a pressure of 4.0 MPa for prevention of pressure increase,
thus resulting in no damage of functional parts due to the increase of pressure in
transportation or storage.
(9) —
Double tube heat
exchanger (Subcooling
heat exchanger)
Used to subcool liquid refrigerant from the electronic expansion valve.
(10) R1T
Thermistor
(Outdoor air: Ta)
Used to detect outdoor air temperature, correct discharge pipe temperature, and
for other purposes.
(11) R21T
Thermistor
(Discharge pipe: Tdi1)
Used to detect discharge pipe temperature, make the temperature protection
control of compressor, and for other purposes.
(12) R3T
Thermistor
(Suction pipe: Ts)
Used to detect suction pipe temperature, and for other purposes.
(13) R4T
Thermistor
(Heat exchanger liquid
pipe: Tf)
This detects temperature of liquid pipe between the air heat exchanger and
refrigerant jacket. Used to make judgments on the recover or discharge
refrigerants to the refrigerant regulator.
(14) R5T
Thermistor
(Subcooling heat
exchanger liquid pipe:
Tsc)
This detects temperature of liquid pipe after subcooling heat exchanger.
(15) R6T
Thermistor
(Subcooling heat
exchanger gas pipe: Tsh)
This detects temperature of gas pipe on the evaporation side of subcooling heat
exchanger. Used to exercise the constant control of superheating degree at the
outlet of subcooling heat exchanger.