Thermistor Functions - Daikin FTX-N Series Service Manual

Thermistor Functions

4. Thermistor Functions

(1) Discharge
 The discharge pipe thermistor is used for controlling discharge pipe temperature. If the
Pipe Thermistor
 The discharge pipe thermistor is used for detecting disconnection of the discharge pipe
(2) Outdoor Heat
 The outdoor heat exchanger thermistor is used for controlling the target discharge pipe
Exchanger
Thermistor
 In cooling operation, the outdoor heat exchanger thermistor is used for detecting the
 In cooling operation, the outdoor heat exchanger thermistor is used for high pressure protection.
(3) Outdoor
 The outdoor temperature thermistor detects the outdoor air temperature and is used for
Temperature
Thermistor
(4) Indoor Heat
 The indoor heat exchanger thermistor is used for controlling the target discharge pipe
Exchanger
Thermistor
 In cooling operation, the indoor heat exchanger thermistor is used for freeze-up protection
 In heating operation, the indoor heat exchanger thermistor is used for detecting the
(5) Room
 The room temperature thermistor detects the room air temperature and is used for controlling
Temperature
Thermistor
77
(3) Outdoor
Temperature
Thermistor
(2) Outdoor Heat
Exchanger
Thermistor
(1) Discharge Pipe
Thermistor
discharge pipe temperature (used in place of the inner temperature of the compressor) rises
abnormally, the operating frequency becomes lower or the operation halts.
thermistor.
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.
disconnection of the discharge pipe thermistor. When the discharge pipe temperature drops
below the outdoor heat exchanger temperature by more than a certain value, the discharge pipe
thermistor is judged as disconnected.
refrigerant shortage detection, input current control, outdoor fan control, liquid compression
protection function, and so on.
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.
control. If the indoor heat exchanger temperature drops abnormally, the operating frequency
becomes lower or the operation halts.
disconnection of the discharge pipe thermistor. When the discharge pipe temperature drops
below the indoor heat exchanger temperature by more than a certain value, the discharge pipe
thermistor is judged as disconnected.
the room air temperature.
Expansion valve
Four way valve
Compressor
SiUS091601EA
(5) Room
Temperature
Thermistor
(4) Indoor Heat
Exchanger
Thermistor
(R23851)
Part 4 Functions and Control