Daikin FTKE25BVM, Service Manual

Page: 100 / 298

Si12-411A Function of Main Structural Parts
Function and Control 89
D Indoor Heat
Exchanger
Thermistor
(DCN)
1. An indoor heat exchanger thermistor is used for controlling target discharge pipe
temperature.
Set a target discharge pipe temperature according to the outdoor and indoor heat exchanger
temperature.
Control the electronic expansion valve opening so that the target discharge pipe
temperature can be obtained.
2. An indoor heat exchanger thermistor is used to prevent freezing.
During the cooling operation, if the temperature drops abnormally, the operating frequency
becomes lower, then the operation must be halted.
3. An indoor heat exchanger thermistor is used for anti-icing control.
During the cooling operation, if the heat exchanger temperature in the room where operation
is halted becomes -1°C, or if the room temperature - heat exchanger in the room where
operation is halted becomes
≥
10°C, it is assumed as icing.
4. An indoor heat exchanger thermistor is used for detecting incorrect wiring.
During the operation of checking incorrect wiring, refrigerant is passed in order from the port
A to detect a heat exchanger temperature, and then wiring and piping will be checked.