LG Therma V AHBW A0 Series Service Manual page 56

Trouble Shooting Guide
Display
Title
code
21
DC Peak
Check Flow Chart
Check the wire
connection.(U,V,W)
Is it normal ?
Yes
Check the resistance of
comp. (No difference at
each terminal)
Is it normal ?
Yes
Check the electricity
leakageof the compressor.
(Refer to comp check table)
Is it normal ?
Yes
Check the input power
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Cause of error
• Instant over current
• Over Rated current
• Poor insulation of IPM
No
Correct
connection
Check Over load condition
- Overcharging of
No
Change
- Pipe Length
Compressor
- Condenser is blocked
- Outdoor fan is locked
❊ Dc link voltage table
No
Change
Model
Compressor
1 Phase
3 Phase
- 56 -
Check point & Normal condition
• An instant over current in the U,V,W phase
- Comp lock
- The abnormal connection of U,V,W
• Over load condition
- Overcharging of refrigerant
- Pipe length.
• Poor insulation of compressor
Is it normal ?
(1 Φ : 230 V ± 10%
3 Φ : 400 V ± 10%)
Yes
Check DC link
capacitor Is it normal?
(Refer to belows)
Yes
refrigerant
No
Change Main PCB 2
Type Non operating
AUUW126C PSC DC300V
AUUW186C PSC DC300V
AUUW246D PFC DC300V
AUUW306D PFC DC300V
AUUW366D PFC DC300V
AUUW426D PFC DC300V
AUUW486D PFC DC300V
AUUW606D PFC DC300V
AUUW368D PSC DC540V
AUUW428D PFC DC540V
AUUW488D PFC DC540V
AUUW608D PFC DC540V
No
Needs electric work
No
Change DC link
capacitor
or Main PCB 2
Remove obstruction
Change outdoor fan
or motor
Change refrigerant
DC Link Voltage
Operating
10% DC280V 10%
10% DC280V 10%
10% DC380V 10%
10% DC380V 10%
10% DC380V 10%
10% DC380V 10%
10% DC380V 10%
10% DC380V 10%
10% DC500V 10%
10% DC680V 10%
10% DC680V 10%
10% DC680V 10%
LGE Internal Use Only