LG Universal System Air Conditioner Service Manual page 135

3.1.2 Discharge pipe control for constant compressor
1) There can be two situations
(a) Sensor is failed (error code for sensor failure will be generated)
(b) Abnormal high temperature discharge temperature (error code for high discharge will be generated)
Both cases unit will stop.
2) Compressor working
(a) If discharge pipe temperature < T1 Compressor ON, LEV on-time control
(b) T2 ≤ discharge pipe temperature < Toff (Hysteresis control) Expansion valve up by ßpulse every 1 min.
If LEV is in the starting control it will follow it as it is.
(c) Discharge pipe temperature ≥ Toff Compressor will be OFF
System will stop if this situation occurs 5 times in 1 hour and error code will be generated.
Toff(105)°C
T2(95)°C
T1(90)°C
COMP
Step
Expansion
valve
D-Pipe temp
ON
On-time
Pulse
control
10
Up
Outdoor Units
ON
OFF
On time
Stop
control
Service Manual 135