Refrigerant Circuit (Piping Diagrams); Rzr18/24Tavju, Rzq18/24Tavju; Refrigerant Circuit Part - Daikin SkyAir RZR-TA Series Service Manual

SiUS281811EA

1. Refrigerant Circuit (Piping Diagrams)

1.1

RZR18/24TAVJU, RZQ18/24TAVJU

No. in
Electric
piping
symbol
diagram
(1) M1C Inverter compressor
(2) M1F Inverter fan
Electronic expansion
(3) Y1E
valve (Main)
(4) Y1S Four way valve
(5) Y2S Solenoid valve (Hot gas)
Solenoid valve
(6) Y3S
(Unload circuit)
(7) S1NPH High pressure sensor
(8) S1NPL Low pressure sensor
High pressure switch (For
(9) S1PH compressor)
Fusible plug
(10) —
Pressure regulating valve
(11) — (Receiver to discharge
pipe)
Thermistor
(12) R1T
(Outdoor air: Ta)
Thermistor
(13) R2T
(Discharge pipe: Tdi)
Thermistor
(14) R3T
(Suction pipe 1: Ts1)
Thermistor (Heat
(15) R4T
exchanger deicer: Tb)
Thermistor
(16) R5T
(Suction pipe 2: Ts2)
Thermistor
(17) R7T
(Liquid pipe: Tl)
Thermistor (Radiation fin)
(18) R10T
Part 2 Refrigerant Circuit
Name
Compressor is operated in multi-steps according to Te and Tc.
The fan rotation speed is varied by using inverter.
While in heating operation, PI control is applied to keep the outlet superheated
degree of air heat exchanger constant.
Used to switch the operation mode between cooling and heating.
Used to prevent the low pressure from transient falling.
Used for unloading operation of compressor.
Used to detect high pressure.
Used to detect low pressure.
In order to prevent the increase of high pressure when an error occurs, this switch
is activated at high pressure of 4.0 MPa (580 psi) 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
(158 to 167°F) to release the pressure into the atmosphere.
This valve opens at a pressure of 4.0 MPa (580 psi) 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 air temperature, correct discharge pipe temperature, and
for other purposes.
Used to detect discharge pipe temperature, make the temperature protection
control of compressor, and for other purposes.
Used to detect suction pipe temperature, keep the suction superheated degree
constant in heating operation, and for other purposes.
Used to detect liquid pipe temperature of air heat exchanger, determine
defrosting operation, and for other purposes.
Used to the calculation of an internal temperature of compressor etc.
Used to detect refrigerant overcharge in check operation, and for other purposes.
Used for outdoor fan speed control, inverter radiation fin temperature control,
pressure difference control.

Refrigerant Circuit (Piping Diagrams)

Function
69