![background image](http://html.mh-extra.com/html/daikin/super-multi-nx-ftxg25jv1bw/super-multi-nx-ftxg25jv1bw_service-manual_3790442044.webp)
Function of Thermistor
SiBE041012_A
33
Function and Control
2. Function of Thermistor
(1) Outdoor Heat
Exchanger
Thermistor
1. The outdoor heat exchanger thermistor is used for controlling target discharge pipe
temperature. The system sets the 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. In cooling operation, the outdoor heat exchanger thermistor is used for detecting
disconnection of the discharge pipe thermistor. When the discharge pipe temperature
becomes lower than the outdoor heat exchanger temperature, the discharge pipe thermistor
is judged as disconnected.
3. In cooling operation, the outdoor heat exchanger thermistor is used for high pressure
protection.
(2) Discharge
Pipe Thermistor
1. The discharge pipe thermistor is used for controlling discharge pipe temperature. If the
discharge pipe temperature (used in place of the inner temperature of the compressor) rises
abnormally, the operating frequency becomes lower or the operation halts.
2. The discharge pipe thermistor is used for detecting disconnection of the discharge pipe
thermistor.
(3) Indoor Heat
Exchanger
Thermistor
1. The indoor heat exchanger thermistor is used for controlling target discharge pipe
temperature. The system sets the 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. In cooling operation, the indoor heat exchanger thermistor is used for freeze-up protection
control. If the indoor heat exchanger temperature drops abnormally, the operating frequency
becomes lower or the operation halts.
3. In heating operation, the indoor heat exchanger thermistor is used for detecting
disconnection of the discharge pipe thermistor. When the discharge pipe temperature
becomes lower than the indoor heat exchanger temperature, the discharge pipe thermistor
is judged as disconnected.
Four way valve
Compressor
(R14247)
(3)
(2)
Electronic
expansion valve
(1)