LG LRFD21855ST, Service Manual

7-2 ICE MAKER FUNCTIONS

7-2-1 Start Position

1. After POWER OFF or Power Outage, check the EJECTOR's position with MICOM initialization to restart. 

2. How to check if it is in place:

- Check HIGH/LOW signals from HALL SENSOR in MICOM PIN. 

3. Control Method to check if it is in place:

(1) EJECTOR is in place,

- It is an initialized control, so the mode can be changed to ice making control.

(2) EJECTOR isn't in place:

A. If EJECTOR is back in place within 2 minutes with the motor on, it is being initialized. If not, go to Step B.
B. If EJECTOR is back in place within 18 minutes after the heater turns from ON to OFF, it is being initialized. If not, it is

not functioning. Repeat Step B with Heater and Motor off.

7-2-2 Ice Making Mode

1. Ice Making refers to the freezing of supplied water in the ice trays. Complete freezing is assured by measuring the

temperature of the Tray with Ice-Making SENSOR. 

2. Ice Making starts after completion of the water fill operation.

3. The Ice Making function is completed when the sensor reaches 19°F(-7°C), 60 to 240 minutes after starting.

4. If the temperature sensor is defective, the ice-making function will be completed in 4 hours.

NOTE : After Icemaker Power is ON, the Icemaker heater will be on for test for 9 sec.

7-2-3 Harvest Mode

1. Harvest (Ice removing) refers to the operation of dropping cubes into the ice bin from the tray when ice-making has

completed.

2. Harvest mode:

(1) The Heater is ON for 30 seconds, then the motor starts.
(2) After performing Step 1 (the Heater is turned OFF), the Ejector will be back in place wthin 18 minutes. (Hall SENSOR

sign = OV). Ice removal is then complete. Then the Ice Maker cycles to the Fill Mode. The water supply fails to start, it
is not functioning. Put the Heater and Motor in the off position. Restart every 2 hours. (Refer to fig.1)

NOTE : If the motor malfunctions and starts before the detect lever rises, MICOM regards the Ice-Removing phase as
completed. Water then starts flowing. To prevent this, MICOM doesn’t switch to water-supply mode, but restarts the ice-
removing mode. If this happens 3 times, the motor is malfunctioning and you should stop the loads (Heater, Motor). Then
restart the Ice-Removing mode every 2 hours. (See Step 2 above.)

- 19 -

Heater

on

off

on

0V

5V

off

30 sec.

10 sec.

Motor

Hall IC

Ice removing
completion point

2 ms

Ice making sensor temperature is 50

°

F(10˚C) 

or more 
Max. 18 minutes
After detect LEVER rises

<fig1. Harvest mode Process>