Function of Thermistor SiBE121123_A
89 Function and Control
3. 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 outdoor 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 drops
below the outdoor heat exchanger temperature by more than a certain value, 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) Gas Pipe
Thermistor
In cooling operation, the gas pipe thermistor is used for gas pipe isothermal control. The system
controls outdoor electronic expansion valve opening so that the gas pipe temperature in each
room becomes equal.
EVB
EVA
Radiant panel
In case of FVXG model
Four way valve
Compressor
(1)
(2)
(3)
(4)
(5)
(R15406)
Indoor electronic
expansion valve
(Motor operated
valve)
Outdoor electronic
expansion valve
(4)
(6)
φ
6
(6)
φ
4