LG MULTI V 5 Manual Book page 79

3. EEV
3.1 Failure Judge Method
■ Cooling
1. Main EEV
1) Basic control
- Variable path mode : Upper EEV Full Close / Lower EEV Full Open
- Low temperature cooling mode : Upper EEV Full Open / Lower EEV Close
2) Failure phenomenon
① Upper EEV leakage
All the refrigerant flows into the upper EEV and decrease the capacity of the lower heat exchanger.
→ SC EEV Open to ensure SC degree
② Lower EEV leakage
Flow rate is concentrated in check valve → Excessive pressure loss
→ Indoor refrigerant noise occurs
2. SC EEV
1) Basic control : SC / SH control
2) Failure phenomenon
① SC EEV open failure : Outdoor SC can not be controlled
→ Indoor refrigerant noise occurs due to insufficient SC
→ Temperature is not lowered even if EEV is opened when discharge temperature emergency control
3. VI EEV
1) Basic control : Inverter start control, Vapor Injection control
2) Failure phenomenon
① VI EEV open failure : CH21 error display, Compressor failure
→ Failure to reduce compressor different pressure during start-up
② VI EEV Close failure : Failure to obtain the degree of discharge superheat,
CH21, Compressor failure → Liquid compression
* SC : Sub Cooling, SH : Super Heating
156
_TROUBLE SHOOTING GUIDE BOOK
■ Heating
1. Main EEV
1) Basic control : Suction the degree of superheat control
2) Failure phenomenon
① Upper EEV open failure
Excessive drop of low pressure, Upper and lower heat exchanger temperature difference 10 ℃ or
more
→ The refrigerant does not flow through the upper heat exchanger and the evaporation amount is
insufficient.
② Lower EEV open failure
Excessive drop of low pressure, Upper and lower heat exchanger temperature difference 10 ℃ or
more
→ The refrigerant does not flow through the lower heat exchanger and the evaporation amount is
insufficient.
2. SC EEV
1) Basic control : Inverter emergency control
2) Failure phenomenon
① SC EEV Open failure : EEV is open but discharge temperature is not lower
→ Open when compressor discharge temperature rises
3. VI EEV
1) Basic control : Inverter start control, Vapor Injection control
2) Failure phenomenon
① VI EEV Open failure : CH21, Compressor failure
→ Failure to reduce compressor different pressure during start-up
② VI EEV Close failure : Failure to obtain the degree of discharge superheat, CH21, Compressor failure
→ Liquid compression
* SC : Sub Cooling, SH : Super Heating
157
_