Refrigerant Circuit
SiENBE18-621
50
Refrigerant Circuit
1. Refrigerant Circuit
1.1
Outdoor Units
No. in
refrigerant
system
diagram
Symbol
Name
Major Function
A
M1C
Inverter compressor (INV)
Inverter compressor is operated on frequencies between 36 Hz and 195 Hz by using
the inverter.
31 steps
D
M1F
M2F
Inverter fan
Since the system is of air heat exchanging type, the fan is operated at 8-step rotation
speed by using the inverter.
E
Y1E
Electronic expansion valve
(Main: EV1)
While in heating operation, PI control is applied to keep the outlet superheated degree
of air heat exchanger constant.
F
Y3E
Electronic expansion valve
(Subcool: EV3)
Pl control is applied to keep the outlet superheated degree of subcooling heat
exchanger constant.
G
Y2S
Solenoid valve (Hot gas: SVP) Used to prevent the low pressure from transient falling.
H
Y3S
Solenoid valve (Unload circuit
SVUL)
Used to the unloading operation of compressor.
M
Y1S
Four way valve
Used to switch the operation mode between cooling and heating.
N
S1NPH High pressure sensor
Used to detect high pressure.
O
S1NPL
Low pressure sensor
Used to detect low pressure.
P
S1PH
HP pressure switch (For INV
compressor)
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.
S
—
Fusible plug
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.
T
—
Pressure regulating valve 1
(Receiver to discharge pipe)
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.
1
R1T
Thermistor (Outdoor air: Ta)
Used to detect outdoor temperature, correct discharge pipe temperature, and others.
2
R2T
Thermistor (INV discharge
pipe: Tdi)
used to detect discharge pipe temperature, make the temperature protection control of
compressor, and others.
3
R3T
Thermistor
(Suction pipe1: Ts1)
used to detect suction pipe temperature, keep the suction superheated degree
constant in heating operation, and others.
4
R4T
Thermistor (Heat exchanger
deicer: Tb)
Used to detect liquid pipe temperature of air heat exchanger, determine defrosting
operation, and others.
5
R5T
Thermistor
(Suction pipe2: Ts2)
Used to the calculation of an internal temperature of compressor etc.
6
R6T
Thermistor (Subcooling heat
exchanger gas pipe: Tsh)
Used to control of subcooling electronic expansion valve.
7
R7T
Thermistor
(Liquid pipe: Tl)
Used to detect refrigerant over charge in check operation, and others.
Summary of Contents for BPMKS967B2B
Page 1: ...SiENBE18 621 E Series Service Manual Applied Models Super Multi Plus Heat Pump...
Page 12: ...SiENBE18 621 List of Functions 1 Part 1 List of Functions 1 List of Functions 2...
Page 19: ...List of Functions SiENBE18 621 8 List of Functions...
Page 33: ...Specifications SiENBE18 621 22 Specifications...
Page 69: ...Refrigerant Flow for Each Operation Mode SiENBE18 621 58 Refrigerant Circuit...
Page 121: ...Indoor Unit SkyAir Models SiENBE18 621 110 Function...
Page 169: ...Instruction SiENBE18 621 158 System Configuration FTXS 20 25 35C Indoor Unit...
Page 371: ...Method of Replacing The Inverter s Power Transistors Modules SiENBE18 621 360 Troubleshooting...
Page 393: ...SiENBE18 621 vi Index...
