Refrigerant Circuit; Rzr18 / 24 / 30Pvju Rzq18 / 24Pvju9 Rzq30Pvju - Daikin SkyAir RZR-P Series Service Manual

SiUS281117

1. Refrigerant Circuit

1.1 RZR18 / 24 / 30PVJU
RZQ18 / 24PVJU9
RZQ30PVJU
No. in
refrigerant Electric
system Symbol
diagram
A M1C Inverter compressor (INV.)
D M1F Inverter fan
Electronic expansion valve
E Y1E
(Main: EV1)
G Y2S Solenoid valve (Hot gas: SVP) Prevents the low pressure from transient falling.
Solenoid valve (Receiver gas
J Y3S
discharging: SVG)
M Y1S Four-way valve
N S1NPH High pressure sensor
O S1NPL Low pressure sensor
High pressure switch (For
P S1PH
INV. compressor)
S — Fusible plug
Pressure regulating valve 1
T —
(Receiver to discharge pipe)
1 R1T Thermistor (Outdoor air: Ta)
Thermistor (Discharge pipe:
2 R2T
Tdi)
Thermistor (Suction pipe 1:
3 R3T
Ts1)
Thermistor (Heat exchanger
4 R4T
deicer: Tb)
Thermistor (Suction pipe 2:
5 R5T
Ts2)
10 R10T Thermistor (Radiation fin)
6
Name
Inverter compressor is operated on frequencies between 52 Hz and 177 Hz by using
the inverter.
17 steps
Because the system is an air heat exchange 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.
Collects refrigerant to receiver.
Switches the operation mode between cooling and heating.
Detects high pressure.
Detects low pressure.
In order to prevent the increase of high pressure when an error occurs, this switch is
activated at high pressure of 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 158 to 167°F to
release the pressure into the atmosphere.
This valve opens at a pressure of 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.
Detects outdoor air temperature, correct discharge pipe temperature, and others.
Detects discharge pipe temperature, make the temperature protection control of
compressor, and others.
Detects suction pipe temperature, keep the suction superheated degree constant in
heating operation, and others.
Detects liquid pipe temperature of air heat exchanger, determine defrosting operation,
and others.
Calculates internal temperature of compressor.
• Outdoor unit fan speed control.
• Inverter radiation fin temperature control.
• Pressure difference control.

Refrigerant Circuit

Major Function
Refrigerant Circuit