If you find yourself troubleshooting an over heat error on a VFD there is a process which can help guide you to the solution. 

First, check the heat sink temperature of the loader and check your trip history. Did a trip occur at 100 degrees Celsius or 212 Fahrenheit or higher?  If so, then check to make sure that the ambient temperature is below 40 degrees Celsius and 104 degrees Fahrenheit. If neither of those are the case then examine the panel cooling system. 

If you do find a discrepancy then you will need to look to the cooling fan. Is the cooling fan running properly? If it is, check to see if there is nothing abnormal about the NTC wire or PIM NTC. Note that models IG5A and IC5 have the NTC inside the PIM.  If nothing is abnormal about the NTC wire then check to see if the control PCB runs normally after it is replaced. If a problem still occurs double check the hardware that is installed. 

If the cooling fan is NOT running normally make sure that it is installed correctly. If that isn't the problem then make sure 24V occurs in the fan connector of the SMPS. If you are getting a correct reading check the fan for any unexpected materials that may be blocking it. Removing the material from inside the fan should solve the problem. If it doesn't then replace the cooling fan with a new one.