200 
9.3 Cooling fan 
The inverter’s cooling fan has a minimum life span of 25,000 operating hours. The actual life 
span depends on the inverter usage and ambient temperature.   
The operating hours can be found through P07.15 (accumulative hours of the inverter). 
Fan failure can be predicted by the increasing noise from the fan bearings. If the inverter is 
operated  in  a  critical  part  of  a  process,  fan  replacement  is  recommended  once  these 
symptoms appear. Replacement fans are available from INVT. 
Replacing the cooling fan   
 Read  and  follow  the  instructions  in  chapter  Safety  Precautions. 
Ignoring  the  instructions  would  cause  physical  injury  or  death,  or 
damage to the equipment.   
1. Stop the inverter and disconnect it from the AC power source and wait for at least the time 
designated on the inverter.     
2. Lever the fan holder off the drive frame with a screwdriver and lift the hinged fan holder 
slightly upward from its front edge. 
3. Free the fan cable from the clip. 
4. Disconnect the fan cable. 
5. Remove the fan holder from the hinges. 
6. Install the new fan holder including the fan in reverse order. 
7. Restore power. 
9.4 Capacitors 
9.4.1 Reforming the capacitors 
The  DC  bus  capacitors  must  be  reformed  according  to  the  operation  instruction  if  the 
inverter has been stored for a long time. The storing time is counted form the producing date 
other than the delivery data which has been marked in the serial number of the inverter.   
Time    Operational principle   
Storing time less than 1 
year 
Operation without charging 
Storing time 1-2 years 
Connect with the power for 1 hour before first ON command   
Storing time 2-3 years 
Use power surge to charge for the inverter   
• Add 25% rated voltage for 30 minutes   
• Add 50% rated voltage for 30 minutes