Error Diagnosis And Countermeasure Flow Chart; Comp Checking Method - LG THERMA V AHNW16606B0 Service Manual

Display
Title
code
DC PEAK
21
(IPM Fault)
WARNING
Before checking PCB(Inverter) or each outdoor electric parts, wait for 3 minutes after the power is off. When measuring at standby
state of power supply, after checking the measurement mode of the meter, be careful of the short-circuits with other parts.
n Error Diagnosis and Countermeasure Flow Chart
Is installation
condition normal?
Yes
Are the resistance
Between each phase and
insulation resistance of Inverter
compressor normal?
Yes
Is compressor
Wire connection
condition normal?
Yes
Is inverter PCB assembly 1 normal?
Yes
Recheck power and installation condition
n Comp checking method
Cause of error
• Instant over current
• Over Rated current
• Poor insulation of IPM
1. Check Pipe clogging/distortion
2. Check Covering (Unit)
3. Check EEV connector assemble condition/normal
No
operation
4. Check refrigerant pressure
→ Reassemble or manage if abnormality found
1. Check resistance between each terminal of compressor
2. Check insulation resistance between compressor
No
terminal and pipe
→ Replace compressor if abnormality found
1. Check inverter PCB assembly 1 U,V,W connector
connection condition
2. Check wire disconnection and wiring
No
3. Check compressor terminal connection condition
(bad contact)
→ Reassemble if abnormality found
Check inverter PCB assembly 1 IPM normality
No
→ Replace inverter PCB assembly 1
Comp
U
V W
Copper
pipe
Comp
- 41 -
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.
Outdoor Fan is stop
• Poor insulation of compressor
Model
AHUW146A2
Terminal Insulation Resistance
U-panel
V-panel
W-panel
Resistance(Ω) at 20°C
U-V 0.438(at 25˚C)
V-W 0.438(at 25˚C)
W-U 0.438(at 25˚C)
≥ 10MΩ
≥ 10MΩ
≥ 10MΩ