12
Setting number
P01873-01 (Ver. 1.9A or later),
P01873-02 (Ver. 1.4A or later)
P01873-01 (Ver. 1.8D or earlier),
P01873-02 (Ver. 1.2F or earlier)
No. 71
Hot gas valve ON time to
prevent ice stuck
Setting range: 0 to
10
sec
* every 1 sec
Setting range: 0 to
20
sec
* every 1 sec
No. 72
Hot gas valve OFF time to
prevent ice stuck
Not adjustable
Setting range: 0 to 60 sec
* every 1 sec
OFF time = 30 sec − No. 71 set
value (sec)
2. OPERATION
This service manual specifies the basic operation of the controller board “Ver. 1.0A”.
[a] SOFT START
1) When the power supply is turned on, the 7-segment LED shows “on” and the hot gas
valve opens. After 30 seconds, the defrost cycle starts.
* If the reset switch is pressed during the 30-second standby time, the unit resets
soft start and immediately starts operation.
[b] WATER PAN OPENS
1) The hot gas valve opens, the actuator motor starts, and the water pan starts to open.
2) After 20 seconds, the water valve opens to supply defrosting water (water pan
cleaning water) for a specific time.
* The defrosting water supply time varies between the water temperatures above
and below 13°C.
* In the initial cycle, the water temperature is not detected and assumed to be below
13°C, resulting in a longer defrosting water supply time.
* The defrosting water supply time is adjustable in the maintenance mode (see “3. [b]
MAINTENANCE MODE”).
3) The opening backup timer starts counting when the water pan starts to open. If the
hall IC does not turn on within 3 minutes, the display shows “EE” and the unit stops
for 60 minutes. If the error recurs after the unit resumes operation, the display shows
“EE” and the unit shuts down (recorded as “E3” in error history).
[c] DEFROST CYCLE
1) After the water pan opens, the hot gas valve opens until the defrost completion
temperature is reached.
2) If the defrost completion temperature is not reached even when the defrost backup
timer counts up (30 minutes after water pan starts to open), the display shows “E2”
and the unit stops.
If the hot gas valve fails to open, the unit may stop with the “E2” error.
