33
Installation and Maintenance
Service Manual
6
Zero-crossing
inspection
circuit
malfunction
of the IDU fan
motor
U8
Operation of remote controller or control
panel is available, but the unit won’t act.
1.Quick de-energization and energization. Wrong
judgement by the controller because the electric-
discharging of capacitor is slow.
2.Zero-crossing inspection circuit of main board for
controller is abnormal.
7
Lack of
refrigerant
or block
protection for
the system(not
applicable to
residential air
conditioner)
or Overload
protection
compressor
F0
The Dual-8 Code Display will show F0
and the complete unit stops.
1.Refrigerant leakage;
2.Indoor evaporator temperature sensor works abnormally;
3.The unit has been plugged up somewhere;
4.The compressor can’t be started up normally. Because
the power voltage for the complete unit is too low, and the
outdoor working condition is too high.
