Circuit Operation Theory; Temperature Control Part Design; Temperature Control Function; Defrosting Function - Samsung RT40MA Service Manual

7. Circuit operation theory

1. Temperature Control and Operational Description of Other Functions

1. Temperature Control Part Design

Freezer Temperature Controller

2. Temperature Control Function

1)Selecting Freezer Temperature
Selecting "Quick cooling~Quick freezing"is possible with turning temperature control knob.
l
Controlled temperature of each temperature control knob position is as follows:
l
Knob Position
Controlled
Temperature
2)Selecting Refrigerator Temperature
Selecting ① ~ ⑧ is possible with turning temperature control knob.
l
Controled temperature of each temperature control knob position is as follows:
l
x
Knob Position
Controlled
6.0
Temperature
Caution) As this controller is by the ROTARY S/W, in case it is off the position, it is set to step 4 automatically.

3. Defrosting Function

1)Defrosting is decided by the accumulated time of comp on.
2)Defrosting proceeds in order of heating → recess time.
3)The first defrosting function after the initial power on starts with 4 hours of accumulated
time of comp on, and then it repeats its function at every 8th hour of comp on.
4)In the process, controlling of defrosting heater ON/OFF is done by EVA-SENSOR. When the
quality of EVA-SENSOR is poor (short/open) defrosting will be terminated only after recess
time function without heating.
5)In the process, comp and fan maintain ON condition, after defrosting heating it operates with
10 min. recess time.
6)defrosting heating point ON and OFF operates by EVA-SENSOR and each temperature is as
follows:
Heater On Point
below -5℃
Quick cooling Normal
-15±1
➁ ➂
4.5 3.0
Heater Off Point
15℃
Refrigerator Temperature Controller
Quick Freezing
-19.0
-21±1
➃ ➄
2.0 1.0
13
Winter
-23±1
➅ ➆
0.0 -1.0
Remark