Freeze-Up Protection Control - Daikin FTKS20D3VMW Service Manual

SiENBE12-713

5.10 Freeze-up Protection Control

A5
Remote Control
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
" Wrong wiring or piping
Supposed
" EV malfunctioning in each room
Causes
" Short-circuit
" Indoor unit heat exchanger thermistor defective
" Room temperature thermistor defective
Service Diagnosis
5 1 4 2 1 3 4 4
If the freeze-up protection control is activated 4 times continuously, the system will be shut
down.
(The 4-time counter will reset itself if any of the following errors does not occur for 60
minutes: OL, radiation fin temperature rise, gas shortage, and compressor startup.)
4
Troubleshooting
247