Daikin Super Multi NX FFQ25B8V1B Service Manual page 123

SiBE121021_C
3. In cooling operation, the outdoor heat exchanger thermistor is used for high pressure
(2) Discharge 1. The discharge pipe thermistor is used for controlling discharge pipe temperature. If the
Pipe Thermistor
2. The discharge pipe thermistor is used for detecting disconnection of the discharge pipe
(3) Gas Pipe 1. In cooling operation, the gas pipe thermistor is used for gas pipe isothermal control. The
Thermistor
(4) Indoor Heat 1. The indoor heat exchanger thermistor is used for controlling target discharge pipe
Exchanger
Thermistor
2. In cooling operation, the indoor heat exchanger thermistor is used for freeze-up protection
3. In cooling operation, the indoor heat exchanger thermistor is used for anti-icing function. If
4. In heating operation, the indoor heat exchanger thermistor is used for heating peak-cut
5. In heating operation, the indoor heat exchanger thermistor is used for detecting
6. When only one indoor unit is operating, the indoor heat exchanger thermistor is used for
7. The indoor heat exchanger thermistor is used for wiring error check function. The refrigerant
(5) Liquid Pipe 1. When only one indoor unit is in heating, the liquid pipe thermistor is used for subcooling
Thermistor
2. In heating operation, the liquid pipe thermistor is used for liquid pipes isothermal control. The
Function and Control
protection.
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.
system controls electronic expansion valve opening so that the gas pipe temperature in each
room becomes equal.
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.
any of the following conditions are met in the room where operation halts, it is assumed as
icing.
The conditions are
Tc ≤ – 1° C
Ta – Tc ≥ 10° C
where Ta is the room temperature and Tc is the indoor heat exchanger temperature.
control. If the indoor heat exchanger temperature rises abnormally, the operating frequency
becomes lower or the operation halts.
disconnection of the discharge pipe thermistor. When the discharge pipe temperature
becomes lower than the maximum indoor heat exchanger temperature, the discharge pipe
thermistor is judged as disconnected.
subcooling control. The actual subcool is calculated with the liquid pipe temperature and the
indoor heat exchanger temperature. The system controls the electronic expansion valve
openings to obtain the target subcool.
flows in order from the port A to detect the indoor heat exchanger temperature one by one,
and then wiring and piping can be checked.
control. The actual subcool is calculated with the liquid pipe temperature and the maximum
indoor heat exchanger temperature. The system controls the electronic expansion valve
openings to obtain the target subcool.
system controls electronic expansion valve opening so that the liquid pipe temperatures in
each room becomes equal.
Function of Thermistor
111