Chapter 5 Methods of Anomaly Diagnosis  | VFD-VJ 
 
 
5-21
5-2-5 Over Heat (oH1) 
Reduce load
Remove the clog
Replace cooling fan
Is airway of cooling fan clogged
Is load too heavy
Is cooling fan running
No
Yes
Yes
No
Yes
No
No
Yes
Yes
No
Hybrid servo controller is 
overheated
Heat sink is 
overheated
Is the temperature of heat sink 
higher than 90
˚
C
Temperature detection circuit on 
circuit board malfunctions.  
Contact Delta for assistance.
It's likely hybrid servo controller breaks 
down or malfunctions due to noise. 
Contact Delta for assistance.
Is ambient temperature within 
regulated range
Adjusted the ambient
 
temperature to regulated range
 
 
  5-2-6 Overload (oL) 
 
Reduce load or increase the 
capacity of hybrid servo controller
Hybrid servo controller is 
overloaded