Chapter 6 Fault Code Information and Maintenance 
 VFD-EL-W 
6-8 
 
Main circuit resistor 
Items to Check  Methods and Criterion 
Maintenance Period 
Daily  Half Year  One Year 
Check for any peculiar odors or 
insulation cracking due to 
overheating. 
Visual inspection, smell.     
Check for any disconnections.  Visual inspection     
Check for damaged connections 
Measure the resistor value with a 
multi-meter 
   
 
Main circuit transformer and reactor 
Items to Check  Methods and Criterion 
Maintenance Period 
Daily  Half Year  One Year 
Check for any abnormal vibrations 
or peculiar odors. 
Visual, auditory inspection and 
smell. 
   
 
Main circuit electromagnetic contactor and relay 
Items to Check  Methods and Criterion 
Maintenance Period 
Daily  Half Year  One Year 
Check for any vibration sounds.  Auditory inspection.     
Check that the contact works 
correctly. 
Visual inspection     
 
Main circuit printed circuit board and connector 
Items to Check  Methods and Criterion 
Maintenance Period 
Daily  Half Year  One Year 
Check for any loose screws 
and connectors. 
Tighten the screws.     
Check for any peculiar odors or 
color changes. 
Visual inspection and smell     
Check for any cracking, 
damage, deformation or 
corrosion. 
Visual inspection     
Check for any leakage of liquid 
or deformation in the 
capacitors. 
Visual inspection     
 
Cooling system cooling fan 
Items to Check  Methods and Criterion 
Maintenance Period 
Daily  Half Year  One Year 
Check for any abnormal 
sounds or vibrations. 
Visual, auditory inspection and turn 
the fan by hand (turn off the power 
first) to check for smooth rotation. 
  
Check for any loose screws.  Tighten the screws.       
Check for any color change 
due to overheating. 
Change fan.