Refrigerant Circuit
SiBE341027
34
Refrigerant Circuit
1.3
RQYQ14·16PY1B
No. in
refrigerant
system
diagram
Symbol
Name
Major Function
(1)
M1C
Inverter compressor (INV.)
Inverter compressor is operated on frequencies 52Hz to 210Hz by using
the inverter. Standard compressor is operated with commercial power
supply only. The number of operating steps is 49 when inverter
compressor is operated in combination with standard co
(2)
M2C
Standard compressor 1 (STD1)
(3)
M3C
Standard compressor 2 (STD2)
(4)
M1F
Inverter fan
Because the system is an air heat exchange type, the fan is operated 8-
step rotation speed by using the inverter.
(5)
M2F
(6)
Y1E
Electronic expansion valve (Main)
While in heating operation, PI control is applied to keep the outlet
superheated degree of air heat exchanger constant.
(7)
Y2E
Electronic expansion valve (Main 2)
(8)
Y3E
Electronic expansion valve
(Subcooling)
PI control is applied to keep the outlet superheated degree of subcooling
heat exchanger constant.
(9)
Y1S
Solenoid valve (Hot gas)
Used to prevent the low pressure from transient falling.
(10)
Y2S
Solenoid valve (Bypass)
Used to bypass the mixing unit during the normal operation.
(11)
Y3S
Four way valve (Heat exchanger)
Used to switch the operation mode between cooling and heating.
(12)
Y4S
Solenoid valve (Mixing unit inlet)
Use to adjust the amount of refrigeration oil and clean pipes during check
operation. Use to prevent refrigerant from flowing into the mixing unit
during normal operation.
(13)
Y5S
Solenoid valve (Circuit of oil return)
Used to adjust the amount of oil in the mixing unit.
(14)
Y6S
Solenoid valve (Close liquid pipe for
stopped outdoor unit)
Used to prevent the accumulation of refrigerant in the non-operating
outdoor units in a multi-outdoor-unit system.
(15)
Y7S
Solenoid valve (Receiver liquid level)
Used to detect the amount of refrigerant.
(16)
Y8S
Solenoid valve (Receiver gas vent)
Used to collect refrigerant to the receiver.
(17)
Y9S
Solenoid valve (Oil regulator outlet)
Used to adjust the refrigeration oil during the check operation.
(18)
Y10S
Solenoid valve (Refrigerant regulator
gas vent pipe)
Used to collect refrigerant to the refrigerant regulator.
(19)
Y11S
Solenoid valve (Refrigerant regulator
liquid pipe)
Used to collect refrigerant to the refrigerant regulator.
(20)
Y12S
Solenoid valve (Refrigerant regulator
gas pipe)
Used to discharge refrigerant from the refrigerant regulator.
(21)
Y13S
Solenoid valve (Refrigerant regulator
liquid outlet)
Used to discharge refrigerant from the refrigerant regulator.
(22)
S1NPH
High pressure sensor
Used to detect high pressure.
(23)
S2NPH
High pressure sensor (Liquid pipe
outlet)
Used to detect pressure of liquid pipe.
(24)
S1NPL
Low pressure sensor
Used to detect low pressure.
(25)
S1PH
High pressure switch (For INV.)
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.
(26)
S2PH
High pressure switch (For STD 1.)
(27)
S3PH
High pressure switch (For STD 2.)
(28)
S4PH
High pressure switch (for control)
In order to prevent the increase of field piping pressure when an error
occurs, this switch is activated at pressure of 3.3 MPa or more to stop the
compressor operation.
(29)
–
Subcooling heat exchanger
Apply subcooling to liquid refrigerant.
(30)
–
Pipe heat exchanger (A)
Heats the refrigerant that flows out of the receiver.
(31)
–
Pipe heat exchanger (B)
(32)
–
Pipe heat exchanger (C)
(33)
–
Fusible plug
The fusible part fuses at a temperature of 70 to 75°C, allow pressure to
escape to the atmosphere. This is in order to prevent the pressure rise in
case of a fire or other abnormal heating.
(34)
–
(35)
–
Pressure regulating valve 1 (Receiver
- Discharge pipe)
Open at 4.0 MPa or more to avoid pressure increase to prevent damage to
functional parts by the pressure increase and to protect the field piping
during transportation and storage.
(36)
–
Pressure regulating valve 2 (Liquid
pipe - Receiver)
Open at 2 to 2.7 MPa or more to avoid pressure increase to prevent
damage to functional parts by the pressure increase and to protect the field
piping during transportation and storage.
(37)
R1T
Thermistor (Outdoor air)
Used to detect outdoor temperature, correct discharge pipe temperature
and others.
(38)
R2T
Thermistor (Receiver liquid level)
Used to detect the refrigerant temperature at the liquid level detection point
of the receiver.
(39)
R31T
Thermistor (M1C discharge pipe)
Used to detect discharge pipe temperature. Used for compressor
temperature protection control.
(40)
R32T
Thermistor (M2C discharge pipe)
(41)
R33T
Thermistor (M3C discharge pipe)
(42)
R4T
Thermistor (Refrigerant regulator
liquid pipe)
Detects the liquid pipe temperature of the refrigerant regulator. Used
during adjustment of refrigerant amount.
(43)
R5T
Thermistor (Subcooling heat
exchanger outlet)
Used to detect the gas pipe temperature on evaporation side of the
subcooling heat exchanger, keep the superheated degree at the
subcooling heat exchanger constant, and others.
(44)
R6T
Thermistor (Liquid pipe)
Used to detect liquid pipe temperature. Used for purpose such as drift
prevention control between heating indoor and outdoor units in multi-
outdoor unit systems.
(45)
R7T
Thermistor (Receiver gas vent outlet)
Used to detect the refrigerant temperature at the liquid level detection point
of the receiver.
(46)
R8T
Thermistor (Suction pipe)
Used to detect suction pipe temperature. Used for purpose such as control
for constant degree of suction superheat during heating.
(47)
R9T
Thermistor (Heat exchanger deicer)
Used to detect liquid pipe temperature of air heat exchanger. Used to
make judgements on defrosting operation.
