Daikin FTX09NMVJU Service Manual page 63

SiUS091601E
2. When the operation mode is heating
Other than below
Heating
(when outdoor temperature
is below -15°C (5°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.
3.11.8 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
followings.
A (seconds)
Functions and Control
When the following condition is fulfilled, the discharge pipe thermistor disconnection is
ascertained.
Discharge pipe temperature +6°C (+10.8°F) < indoor heat exchanger temperature
SC
(Subcooling)
Target discharge pipe temperature
Actual discharge pipe temperature
Previous discharge pipe temperature
All outdoor units
10 ~ 30
The time depends on the opening of the electronic expansion valve.
A (seconds)
09/12 class 15 class
720 540
1200 1800
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)
Control Specification
(R23014)
52