8.3 Main Protection 
8.3.1 Time Delay at restart for the compressor 
8.3.2 Fan Speed is out of control.(except MS9A-24HRN1-QB8W models) 
----When the indoor fan speed keeps too low or too high for certain time, the unit will stop and the LED 
will display the failure   
8.3.3 Current protection 
 
A zone : The current exceeds I
3SEC
 for 5 seconds, the compressor and outdoor fan will shut off. 
B zone: The current exceeds I
5min
 for 5 minutes, the compressor and outdoor fan will shut off. 
C zone: The current exceeds I
FAN
, the outdoor fan will shut off if AC is in heating mode. If AC is in 
cooling mode, the indoor fan will run at low speed. 
8.3.4 Zero crossing detection error protection(except MS9A-24HRN1-QB8W models) 
If AC can not detect zero crossing signal for 4 minutes or the zero crossing signal time interval is not 
correct, the unit will stop and the LED will display the failure. The correct zero crossing signal time 
interval should be between 6-13ms.