LG Multi V CRUN Series Service Manual page 162

Operation detail
(3) Control the discharge temperature
1. At the temperature of compressor discharge pipe >100°C, turn on the liquid injection valve.
(4) DC peak control
1. Criterion for DC peak : if the fault signal from IPM(Intelligent power moudule) is occurred continuously for
2. As soon as DC peak occurs, inverter compressor is turned off immediately.
3. After inverter compressor turned off, 3minutes later if there is no DC peak signal, then restart compres-
sor.
(5) CT(cirremt tramsfprmer) sensor fault error
Detection for CT sensor fault
Criterion for CT sensor fault(which is judged from operation current for each frequency)
After Inverter Compressor Off
(6) Over upper limit voltage and below lowest limit voltage
If the voltage of system input power exceed the upper limit(415V) of rating voltage(380 ~ 415V) by 15%
over(478V or more) or is below the lowest limit(380V) of rating voltage by 20%(304V or less) then the
compressor is turned off, and restart 3 minutes later.
(7) Controls for error occurrence
1. DC peak error
- Restart 3 minutes later.
- System down if the error occurs 3 or more times in an hour
2. CT sensor error
- Restart 3 minutes later.
- System down if the error occurs 3 or more times in an hour
3. Sensor error
- During the error signal is on, the compressor can not be turned on
4. Transmission error
- If the transmission with all of indoor unit is ceased, then compressor is turned off
- If the transmission between inverter PC board and control PC board in outdoor unit, then all of the
compressor is turned off.
162 Outdoor Unit
Inverter compressor,
Comp.: off
A
115°C
Frequency: 10Hz down
B
110°C
ICOF: keep up the frequency
C
100°C
D
Comp.: normal operation
1.8ms, then it is judged that
DC peak occurred.
CT value
CT > 1.5A for 10 seconds
95°C
ICOF: Inverter Compressor Operation Frequency