Daikin FTXS09HVJU - Function of Thermistor

SiUS04-904 Function of Thermistor
Function and Control 35
2. Function of Thermistor
A Outdoor Heat
Exchanger
Thermistor
1. The outdoor heat exchanger thermistor is used for controlling target discharge pipe
temperature.
The system sets a target discharge pipe temperature according to the outdoor and indoor heat
exchanger temperature, and controls the electronic expansion valve opening so that the target
discharge pipe temperature can be obtained.
2. The outdoor heat exchanger thermistor is used for detecting disconnection of the discharge
thermistor when cooling.
When the discharge pipe temperature becomes lower than the outdoor heat exchanger
temperature, the discharge pipe thermistor is judged as disconnected.
3. The outdoor heat exchanger thermistor is used for high pressure protection during cooling
operation.
B Discharge
Pipe Thermistor
1. The discharge pipe thermistor is used for controlling the temperature of the discharge pipe.
If the temperature of the discharge pipe (used in place of the inner temperature of the
compressor) rises abnormally, the operating frequency drops or the operation halts.
2. The discharge pipe thermistor is used for detecting disconnection of the discharge thermistor.
C Indoor Heat
Exchanger
Thermistor
1. The indoor heat exchanger thermistor is used for controlling target discharge pipe temperature.
The system sets a target discharge pipe temperature according to the outdoor and indoor heat
exchanger temperature, and controls the electronic expansion valve opening so that the target
discharge pipe temperature can be obtained.
2. The indoor heat exchanger thermistor is used for preventing freezing.
During the cooling operation, if the temperature drops abnormally, the operating frequency
lowers, then the operation halts.
3. The indoor heat exchanger thermistor is used for detecting disconnection of the discharge pipe
thermistor when heating.
When the discharge pipe temperature becomes lower than the indoor heat exchanger
temperature, the discharge pipe thermistor is judged as disconnected.
The indoor heat exchanger thermistor is also used for preventing abnormal high pressure.
Four way valve
Compressor
(R5204)
A
C
B
Electronic
expansion valve