Daikin FTKM-U Series Service Manual page 48

Control Specification
3.9.8 Discharge Pipe Thermistor Disconnection Control
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,
operates for a specified time, and then stops.
After 3 minutes, 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 repeatedly, the system is shut down. When the compressor runs
for 60 minutes without any error, the error counter is reset.
Details Determining thermistor disconnection
When the starting control finishes, the detection timer for disconnection of the discharge pipe
thermistor (A seconds) starts. When the timer is over, the following adjustment is made.
When the following condition is fulfilled, the discharge pipe thermistor disconnection is
ascertained.
Discharge pipe temperature + B°C < outdoor heat exchanger temperature
A (seconds)
B (°C)
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.
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SiMX042215E
Part 4 Functions and Control