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

SiE12-411

5.10 Freeze-up Protection Control

A5
Remote
Controller
Display
Outdoor Unit LED
A
Display
Method of Indoor unit icing, during cooling operation, is detected by checking the temperatures sensed by
Malfunction the indoor unit heat exchanger thermistor and room temperature thermistor that are located in a
shut-down room.
Detection
Malfunction In the cooling mode, the following conditions (A) and (B) are kept together for 5 minutes.
(A) Indoor unit heat exchanger temperature ≤ –1°C
Decision
(B) Indoor unit heat exchanger temperature ≤ Room temperature –10°C
Conditions
" If the indoor unit icing protector is activated four times straight, the system will be shut down.
" Wrong wiring or piping
Supposed
" Ev malfunctioning in each room
Causes
" Short-circuit
" Indoor unit heat exchanger thermistor defective
" Indoor unit thermistor defective
Service Diagnosis
5 1 4 2 1 3 4 4
(The 4-time counter will reset itself if any of the following errors does not occur during the
compressor running time (total time): OL, radiation fin temperature rise, gas shortage, and
compressor startup.)
<Total 60 minutes>
4
Troubleshooting
179