Freeze-Up Protection Control Or High Pressure Control - Daikin Super Multi NX C-Series Service Manual

Troubleshooting
5.4

Freeze-up Protection Control or High Pressure Control

A5
Remote
Controller
Display
" High pressure control (heat pump model only)
Method of
Malfunction
Detection
" The freeze-up protection control (operation halt) is activated during cooling operation
" High pressure control
Malfunction
Decision
Conditions
" Freeze-up protection
When the indoor unit heat exchanger temperature is below 0°C during cooling operation.
" Operation halt due to clogged air filter of the indoor unit.
Supposed
" Operation halt due to dust accumulation on the indoor unit heat exchanger.
Causes
" Operation halt due to short-circuit.
" Detection error due to faulty indoor unit heat exchanger thermistor.
" Detection error due to faulty indoor unit PCB.
170
During heating operations, the temperature detected by the indoor heat exchanger
thermistor is used for the high pressure control (stop, outdoor fan stop, etc.)
according to the temperature detected by the indoor unit heat exchanger thermistor.
During heating operations, the temperature detected by the indoor heat exchanger
thermistor is above 65°C
SiE12-411
Service Diagnosis