![background image](http://html1.mh-extra.com/html/daikin/super-multi-nx-ffq25b8v1b/super-multi-nx-ffq25b8v1b_service-manual_4061781137.webp)
SiBE121021_C
Control Specification
Function and Control
125
4.12.10 Disconnection of the Discharge Pipe Thermistor
Outline
The disconnection of the discharge pipe thermistor is detected by comparing the discharge pipe
temperature with the condensing temperature. If the discharge pipe thermistor is disconnected,
the electronic expansion valve opens according to the outdoor temperature and the operation
frequency, and operates for a specified time, and then stops.
After 3 minutes of waiting, the operation restarts and checks if the discharge pipe thermistor is
disconnected. If the discharge pipe thermistor is disconnected, the system stops after operating
for a specified time.
If the disconnection is detected 4 times in succession, then the system is shut down. When the
compressor runs for 60 minutes without any error, the error counter is reset.
Detail
Detect Disconnection
When the starting control (about 660~810 seconds) finishes, and the 9-minute timer for the
compressor operation continuation is not counting time, the following adjustment is made.
1. When the operation mode is cooling
When the following condition is fulfilled, the discharge pipe thermistor disconnection is
ascertained.
Discharge pipe tempe 6°C < outdoor heat exchanger temperature
2. When the operation mode is heating
When the following condition is fulfilled, the discharge pipe thermistor disconnection is
ascertained.
Discharge pipe tempe 6°C < highest indoor heat exchanger temperature
Adjustment when the thermistor is disconnected
When the disconnection is ascertained, the compressor continues operation for 9 minutes and
then stops.
When the compressor stops repeatedly, the system is shut down.
4.12.11Control when frequency is changed
When the target discharge pipe temperature control is active, if the target frequency is changed
for a specified value in a certain time period, the target discharge pipe temperature control is
canceled and the target opening of the electronic expansion valve is changed.