Anti-Icing Function - Daikin SUPER MULTI NX G Series Service Manual

Troubleshooting
5.9

Anti-icing Function

A5
Remote
Controller
Display
Outdoor Unit LED
A
Display
Method of
During cooling operation, indoor unit icing is detected by checking the temperatures sensed by the
Malfunction indoor heat exchanger thermistor and the room temperature thermistor that are located in a shut-
down room.
Detection
 In cooling operation, the both conditions (A) and (B) are met for 5 minutes.
Malfunction
Decision
Conditions
 If the error repeats 4 times, the system is shut down.
 Reset condition: Continuous run for about 60 minutes without any other error
 Wrong wiring or piping
Supposed
 Defective electronic expansion valve
Causes
 Short-circuited air
 Defective indoor heat exchanger thermistor
 Defective room temperature thermistor
113
1 2 3 4
(A) Room thermistor temperature – Indoor heat exchanger temperature ≥ 10°C (18°F)
(B) Indoor heat exchanger temperature ≤ –1°C (30°F)
SiUS12-928_A
Service Diagnosis