Daikin 3MKS50DVM, Service Manual

Page: 111 / 403

Function of Main Structural Parts Si12-619A
98 Function and Control
D Indoor Heat
Exchanger
Thermistor 1. The indoor heat exchanger thermistors are used for controlling target discharge
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 temperature can be obtained.
2. The indoor heat exchanger thermistors are used for preventing freezing.
During the cooling operation, if the temperature drops abnormally, the operating frequency
becomes lower, then the operation halts.
3. The indoor heat exchanger thermistors are 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 temperature in the
room where operation is halted becomes
≥
10°C, it is assumed as icing.
4. The indoor heat exchanger thermistors are used for detecting incorrect wiring.
During 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.