LG Multi V CRUN Series

Service Manual 167
Operation detail
(2) Control to prevent low pressure
1. If the measured pressure(transformed absolute pressure)from low-pressure sensor satisfies the condi-
tion, take 1 minute periodic control like following graph.
(3) Control the discharge temperature
1. At the temperature of compressor discharge pipe >115°C, turn on the liquid injection valve.
2. With the control of discharge temperature, the control of LEV in indoor unit carried out like following
graph.
Cooling operation Heating operation
B
Comp.: Off
Comp.: steps down
Outdoor fan: off/off
Hot gas bypass: on
Comp.: normal step
Outdoor fan: normal
Bypass valve: normal
D
A
C
Comp.: keep up the step
Outdoor fan: off/off
Hot gas bypass: on
Comp.:off
Comp.: steps down
Outdoor fan: high/high
Hot gas bypass: on
Comp.: normal step
Outdoor fan: normal
Bypass valve: normal
D
A
B
C
Comp.: keep up the step
Outdoor fan : high/high
Hot gas bypass: on
Inverter compressor,
Constant speed compressor
(the existing control)
B
A
Comp.: off
Liquid injection: off
Frequency: down
Liquid injection: on
C
D
ICOF: keep up the Frequency
Liquid injection: on
(CSC,InvC)125°C
(InvC)120°C
(CSC,InvC)115°C
95°C
Comp.: normal operation
Liquid injection: off
Inverter compressor
(Indoor unit emergency control)
95°C
Comp.: normal step
Indoor unit table: return to normal
D
105°C
Indoor LEV Control
C
CSC: Constant Speed Compressor
InvC: Inverter Compressor
ICOF: Inverter Compressor Operation Frequency