Chapter 5   Troubleshooting and maintenance 
 5-11  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Is MCCB 
applied? 
Can MCCB be 
applied? 
 
Are voltages 
between power 
terminals correct? 
Is LED lit? 
 
Are there outputs between the 
U,V, and W  terminals of the 
motor? 
 
Are outputs between 
U,V,W even 
Short circuited wiring 
․The power is abnormal 
․Incorrect wiring 
N310fault 
The operation switch is set to 
“RUN’ position 
N310 fault 
N310 fault 
YES (within ±3% of the normal value) 
YES (voltage deviation between output pairs are even if 
within ±3% of the normal value without the motor 
․Motor 
․Motor faults 
․Incorrect  wiring 
YES 
YES 
O 
O 
 
O 
Is the operation switch 
in “RUN’ ? 
O 
O 
O 
O 
The motor can not run 
z  Figure 5-4  Motor RUN failure Flow chart