This will cause unnecessary wear on the contactor and
there will always be a slight delay while the inverter 
initialises.

Variable frequency devises not making use of any 
contactors, since the speed and rotation reverse can be 
done with the circuit itself.
VFD having control of supply frequnecy and speed can be 
changed with that.

This will cause unnecessary wear on the contactor and
there will always be a slight delay while the inverter 
initialises.ie.if contactor placed in between vfd and motor 
response time of contactor gettting on is slow compare to 
vfd response speed so return current wii affect the 
electronic bords.thats y contactors not not used in output 
of vfd.