Protection Logic - LG LSFXC2476 Series Service Manual

10-2 Check B
B1. LED blinks once, then repeats (FCT0 Fault: A-Inverter)
Blink OFF Blink OFF
- Purpose: Detecting motor current and voltage error
- Check voltage at point A (Motor Voltage), point B (Motor Current) and Point C (Capacitor
Voltage) when compressor is off.
- Spec: Points A, B, & C 2.5V ± 0.3V
Protection
Blink 1 time
logic
(FCT 0) Check B1
Check B
Out of spec?
(2.2 - 2.8V)
N
Reset Power
※ Caution : Devices should not be short-circuited during check C
B2. LED blinks two times, then repeats (Stroke Trip: A & E Inverters)
Blink Blink OFF Blink Blink OFF
- Purpose: Prevent abnormally long piston strokes.
- Case 1. If compressor doesn't work and LED blinks - Cause: Possibly harness from compressor to PCB might be
defective.
- Case 2. If compressor works intermittently and LED blinks - Cause: Condenser Fan or Freezer Fan is not running. Sealed
system problem such as moisture restriction, restriction at capillary tube or refrigerant leak.
- Logic: Compressor is forced to off and then tries to restart after 1 minute.
Protection
Blink 2 times
logic
(Stroke Trip) Check B2
Check B
Doesn't work
Replace
Driver PCB
OK
NG
Fix Cycle
Cycle Check E
Repeat
Check Procedure
Y
Replace Driver PCB
Y
Compressor
N
Compressor
Works Intermittently
Y
N
Stroke Trip
Occur?
N
Fix Harness
Y
Harness
Connecting
Check C
Y
Reset
Power
- 94 -

Protection Logic

GND
Voltage
GND
C
A
Protection Logic
Capacitor
N
Replace
Spec.
Capacitor
Check C
Y
Compressor
N
Replace
Damage
Compressor
Check C
Y
B