Daikin ALTHERMA HT Service Manual page 24

Refrigerant Circuit
EKHBRD 011/014/016 AC/AD(V1/Y1)
No. in
refrigerant
Symbol
system
diagram
Inverter compressor on
A M1C
R-134a
B Y1R Four way valve
C B1PL Low pressure sensor
D B1PH High pressure sensor
E S1PH High pressure switch
F K1E Electronic expansion valve
G K2E Electronic expansion valve
H M1P DC inverter pump
Thermistor protector water
I Q2L
piping
3 way valve (option for water
J K1S
tank)
1 R3T Liquid thermistor R-410A
2 R6T Discharge thermistor
3 R7T Liquid thermistor R-134a
4 R4T Returning water thermistor
5 R5T Leaving water thermistor
12
Name
Inverter compressor is operated on frequencies between 40 Hz and 210 Hz by using
the inverter. Max. of 30 steps.
Used to switch the operation mode between heating and defrost. Not activated during
heating (opposite concerning outdoor unit).
Used to detect low pressure.
Used to detect high pressure.
In order to prevent the increase of high pressure when a malfunction occurs, this
switch is activated at high pressure of 3.8 MPa or more to stop the compressor
operation.
Used to regulate the refrigerant flow of R-410A.
Used to regulate the refrigerant flow of R-134a.
Used to regulate water flow to achieve a constant ∆T.
Used to protect the water system against high temperatures.
Used to switch over between space heating and domestic hot water.
Subcool calculation.
Used to detect discharge pipe temperature, make the temperature protection control of
compressor, and others.
Subcool calculation.
Used to control and protect the water system.
Used to control and protect the water system.
Major Function
ESIE09-08B
Refrigerant Circuit