LG Multi-Inverter Service Manual page 73

4. Trouble Shooting
¢º ¢º A4UW276FA3/A5UW306FA3/A5UW406FA3/A7UW406FA3/A8UW486FA3/A9UW566FA3
Display
Title
code
05
Title
/
Communication
(Indoor ¡ Outdoor)
53
Check Point
1. Check the input power AC230V. (Outdoor, Indoor unit)
2. Check the communication wires are correctly connected.
Adjust the connection of wire Confirm the wire of "Live",
"Neutral"
3. Check the resistance between communication line and
GND. (Normal : Over 2MΩ)
4. Check the connector for communication is correctly con-
nected.
5. If one indoor unit is operated normally, outdoor PCB is no
problem.
Check the another indoor unit.
* CH05 is displayed at indoor unit, CH53 is displayed at
outdoor unit.
6. If all indoor unit is displayed CH05 but outdoor PCB not
display
CH53 : Check the CN_COM and CN_POWER is correctly
connected.
• 27/30/40k
1. In Case of CH53, Check the Connection ¡ L , N at the ter-
minal block
• 48/56k
1. In Case of CH05, Check the Connection ¡ CN-POWER,
CN-COMM at the Main PCB
2. In Case of CH53, Check the Connection ¡ CN-COMM at
the Main PCB ¡ L , N at the terminal block
N
CN-Power
< MAIN PCB >
Copyright ©2007 LG Electronics. Inc. All right reserved.
Only for training and service purposes
Cause of error
• Communication poorly
CN-COMM
- 72 -
Check point & Normal condition
• Power input AC 220V. (Outdoor, Indoor)
• The connector for transmission is disconnected.
• The connecting wires are misconnected.
• The communication line is shorted at GND.
• Transmission circuit of outdoor PCB is abnormal.
• Transmission circuit of indoor PCB is abnormal.
L
< TERMINAL BLOCK >
L N
N
L
N
LGE Internal Use Only