Lack Of Heating - LG MULTI V 5 Manual Book

2.2 Not reach target low pressure
Checking Item Symptom Judgment
Not reach the target
low pressure under Bypass by defec-
full / partial / single tive outdoor valve
operation
Comp. max
Not reach the target
Hz operation
low pressure under
full operation, but Lack of outdoors
reach the target capacity
low pressure under
partial operation
Compressor
Not max Hz
protection control
operation
operation
Compressor opera-
tion limit by exces- High outdoor
sive high pressure temperature
drop
Fan. max RPM Defective installa-
operation tion of outdoor unit
Excessive foreign
substance of
outdoor heat
exchanger
Difective of fan
Not reach max.
motor, motor shaft,
RPM under max.
fan fixing screw,
RPM display on the
fan balance and
LGMV
Not max. RPM
fan breakage
operation
Fan heatsink tem-
perature limit
Fan lock
※ Compressor operation : The compressor controls the Hz to reach the target low pressure during the
cooling operation.
- If the compressor does not reach the target low pressure while the compressor is operating at Max.
Hz, the outdoor capacity is insufficient compared to the indoor load or the flow is bypassed.
- If the compressor is not in Max Hz operation, it is in emergency control to limit compressor operation.
※ Fan operation : During cooling operation, the fan controls the RPM to match the target high pressure.
- If the present high pressure is higher than the target high pressure, the RPM is raised.
- If the present high pressure is lower than the target high pressure, the RPM is decreased.
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_TROUBLE SHOOTING GUIDE BOOK
Countermeasure
Check the outdoor valve
Check the outdoor installation environment
Remove the foreign substance
Check the amount of thermal grease between
the fan PCB and the heat sink.
Remove foreign substance around the fan
operation.

3. Lack of Heating

3.1 Reach target high pressure
Checking Item Symptom Judgment
Refrigerant overcharging
Heating overload
The degree of
subcooling of ≥ 10 ℃
Defective temp. sensor of indoor unit
indoor unit
Defective EEV of indoor unit
Defective installation of indoor unit
※ The degree of subcooling of indoor unit (It may be different depending on the outdoor unit control)
> 5 ℃ : EEV Open
< 5 ℃ : EEV Close
Countermeasure
Check the amount of refrigerant
Recheck the load design, Check the
ambient air flow, (if duct type) inlet /
outlet chamber installation
Check the temperature sensor of
indoor unit
Check the indoor unit EEV
Check the indoor installation environ-
ment
067
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