LG ARNU Series, Service Manual

Page: 105 / 226

Service Manual 105
Test Run
7. Test Run
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Check to see whether there is any refrigerant leakage, and slack of power or transmission cable.
Confirm that 500 V megger shows 2.0 M
Ω
or more between power supply terminal block and ground.
Do not operate in the case of 2.0 M
Ω
or less.
NOTE: Never carry out megaohm check over terminal control board. Otherwise the control board
would be broken.
Immediately after mounting the unit or after leaving it turned off for an extended length of time,
the resistance of the insulation between the power supply terminal board and the ground may
decrease to approx. 2 M
Ω
as a result of refrigerant accumulating in the internal compressor.
If the insulation resistance is less than 2 M
Ω
, turning on the main power supply and energizing
the crankcase heater for more than 6 hours will cause the refrigerant to evaporate, increasing
the insulation resistance.
Check if high/low pressure common pipe, liquid pipe and gas pipe valves are fully opened.
NOTE: Be sure to tighten caps.
Check if there are any problems in automatic addressing or not:
Check and confirm that there are no error messages in the display of indoor units or remote controls
and LED in outdoor units.
7.1 Checks Before Test Run
CAUTION
when cutting main power of the Multi V
• Always apply main power of the outdoor unit during use of product
(cooling season/heating season).
• Always apply power before 6 hours to heat the crank case heater where performing test run after
installation of product. It may result in burning out of the compressor if not preheating the crank
case with the electrical heater for more than 6 hours.(In case of the outdoor temperature below 10°C)