Daikin FTK Series Service Manual page 53

Control Specification
For cooling mode:
Discharge pipe temperature + C°C (°F) < outdoor heat exchanger temperature
C (°C)
C (°F)
For heating mode:
Discharge pipe temperature + D°C (°F) < indoor heat exchanger temperature
D (°C)
D (°F)
When the thermistor is disconnected
When the disconnection is ascertained, the compressor continues operation for 9 minutes and
then stops.
If the compressor stops repeatedly, the system is shut down.
3.12.11 Target Discharge Pipe Temperature Control
The target discharge pipe temperature is obtained from the indoor and outdoor heat exchanger
temperature, and the electronic expansion valve opening is adjusted so that the actual
discharge pipe temperature becomes close to the target discharge pipe temperature. (Indirect
SH (superheating) control using the discharge pipe temperature)
The electronic expansion valve opening and the target discharge pipe temperature are adjusted
every A seconds. The opening degree of the electronic expansion valve is adjusted by the
following.
 Target discharge pipe temperature
 Actual discharge pipe temperature
 Previous discharge pipe temperature
A (seconds)
48
09 12
A 10 10
B 720 720
6 6
09 12
A 10 10
B 720 720
42.8 42.8
09 12
6 6
09 12
42.8 42.8
SC
(Subcooling)
10 ~ 20 (depending on the model)
18 24
10 10
540 540
6 6
18 24
10 10
540 540
42.8 42.8
18 24
6 6
18 24
42.8 42.8
The target discharge pipe
temperature is set as to become
the target SH.
The inclination does not change
depending on the operating condition.
SH
(Superheating)
DAMA-SM-21-001
Functions and Control