Hot Gas Bypass Valve - LG Multi V CRUN Series Service Manual

Operation detail
Control of Reversing Valve
1. Initial state: keep up OFF state
2. Cooling and Deicing operation: OFF
Heating operation : ON
3. Change operation mode(Cooling
4. Compressor stop because of Thermo-OFF: keep up the present state.

Hot Gas Bypass Valve

(1) General control
1. At initial start of compressor: Turn on for 1 min. ( Inverter comp. frequency :40Hz + Constant speed
comp.: OFF)
2. After 5 seconds from compressor OFF: Turn on for 10 minutes
(This operation is resulted in equilibrium of pressure)
Deicing Operation
(1) The start condition of deicing operation
1. 10 minutes passed, since compressor starts
2. One of the two TOHEXP is continuously under the temperature of start condition of deicing operation
for 20 seconds or more.
Oil Return Operation
(1) Conditions for oil return operation
1. Compressor on time (normal operation) is 6 hours or more.
2. After deicing operation or oil return operation is finished, the cumulative time is reset
(2) Process of oil return operation
1. Change the Step to 35 (55Hz + Constant speed comp.: On).
2. In heating operation, oil return operation is performed in cooling mode by turning reversing valve off.
3. The method of handling reversing valve is the same that of same deicing operation
(3) Finishing oil return operation
1. After oil return operation carried out for 3 minutes, return to normal operation.
Safety Control
(1) Control to prevent high pressure
1. If the measured pressure(transformed absolute pressure)from high-pressure sensor satisfies the condi-
tion, take 1 minute periodic control like following graph.
Cooling operation
A
Comp.: decrease the step
B
Outdoor fan: high/high
C Comp.: keep up the step
Outdoor fan: high/high
D
Comp.: normal step
Outdoor fan: normal
166 Outdoor Unit
Heating): 3minutes restarting, reversing valve ON.
Comp.: off
Heating operation
A
Comp.: off
Comp.: decrease the step
B
Outdoor fan: off/off
Comp.: keep up the step
C
Outdoor fan: off/off
D
Comp.: normal step
Outdoor fan: normal