Hitachi RAS-8.0HNBRMQ1 - Page 106

99
Restart Operation
Restart operation after the crank-
case heater is ON for 8 hours.
Driver board is damaged,
replace the driver board.
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Correct refrigerant charging
amount. 
Fasten the wiring.
Check the power supply voltage,
remove the fault to avoid the voltage
too low or too high.
Is electric reactor wiring loose?
Is crank case heater ON? 
Yes
Yes
Yes
Yes
No
No
No
No
Yes
Check if compressor wirings are
connected reversely? Is electric reactor
wiring secure?
Replace compressor, if
faulty.
Is the power supply voltage within the
range of the rated voltage?
Is refrigerant overcharged? 
Is the power supply voltage higher than
85% of the rated voltage during
operation?
Is there any other high-power equipment
starting during the operation? Is the
power voltage higher than 85% of the
rated voltage?
No
Yes
No
Yes
Yes
Yes
No
Is electronic expansion valve of outdoor
unit locked? 
Replace electronic expansion valve.
Check compressor.
Is the pressure too highϋ
Check if the electronic
expansion valve and stop
valves are not open.
Check if the heat exchanger is
blocked or the fan motor of
outdoor unit is not running.
No
Yes
No
No
TROUBLESHOOTING