Cooling Only Model - Daikin G-Series Service Manual

Function of Thermistor
2.2

Cooling Only Model

A Outdoor Heat 1. The outdoor heat exchanger thermistor is used for controlling target discharge pipe
Exchanger
Thermistor
2. The outdoor heat exchanger thermistor is used for detecting disconnection of the discharge
3. The outdoor heat exchanger thermistor is used for high pressure protection during cooling
B Discharge 1. The discharge pipe thermistor is used for controlling temperature of the discharge pipe.
Pipe Thermistor
2. The discharge pipe thermistor is used for detecting disconnection of the discharge
C Gas Pipe 1. In cooling, the gas pipe thermistors are used for gas pipe isothermal control.
Thermistor
D Indoor Heat 1. The indoor heat exchanger thermistor is used for controlling target discharge pipe
Exchanger
Thermistor
2. The indoor heat exchanger thermistors are used to prevent freezing.
3. The indoor heat exchanger thermistor is used for anti-icing control.
78
A
B
Compressor
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 pipe temperature can be obtained.
thermistor when cooling.
When the discharge pipe temperature becomes lower than the outdoor heat exchanger
temperature, the discharge pipe thermistor is judged as disconnected.
operation.
If the temperature of discharge pipe (used in place of the inner temperature of the
compressor) rises abnormally, the operating frequency drops or the operation halts.
thermistor.
The system controls electronic expansion valve opening so that gas pipe temperature in
each room becomes equal.
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 pipe temperature can be obtained.
During the cooling operation, if the temperature drops abnormally, the operating frequency
becomes lower, then the operation halts.
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.
Expansion valve
EV
A
EV
B
C D
Function and Control
SiBE12-933_A
(R4688)