Daikin FFQ25B9V1B - Function of Thermistor

SiBE121135 Function of Thermistor
Function and Control 105
3. Function of Thermistor
 Illustrations are for 4-room models as representative and have 4 lines of indoor unit system
(A ~ D). 3-room models have 3 lines (A ~ C) and 5-room models have 5 lines (A ~ E).
Cooling Only Model
Heat Pump Model
(1) Outdoor Heat
Exchanger
Thermistor
1. The outdoor heat exchanger thermistor is used for controlling the target discharge pipe
temperature. The system sets the target discharge pipe temperature according to the
outdoor and indoor heat exchanger temperature, and controls the 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 the
disconnection of the discharge pipe thermistor. When the discharge pipe temperature
becomes lower than the outdoor heat exchanger temperature, the discharge pipe thermistor
is judged as disconnected.
3. In cooling operation, the outdoor heat exchanger thermistor is used for high pressure
protection.
EVC
EVD
EVB
EVA
Compressor
(1)
(2)
(3)
(4)
(R17248)
DCBA
Outdoor electronic
expansion valve
Four way valve
Compressor
EVC
EVD
EVB
EVA
(1)
(2)
(3)
(4)
(5)
(R17159)
DCB
Radiant panel
A: In case of FVXG model
Indoor electronic
expansion valve
(Motor operated
valve)
(4)
(6)
φ
6
(6)
φ
4
Outdoor electronic
expansion valve