Another VFD question. Is it worth buying a higher capacity unit?

[Neale]

I did read somewhere that VFD's don't like contactors etc inline with the motor, but I have also read that people just wire them up to the main input of the machine and they work ok. No bypassing of contactors, etc.

I think that that's pretty much the point at issue - the common lower-power VFDs don't like live switching - don't put any kind of switch/relay/contactor between VFD and motor - and some (the better ones? Read "cost more...") are OK. Have to check with supplier to find out which is which!

[JAZZCNC]

I think that that's pretty much the point at issue - the common lower-power VFDs don't like live switching - don't put any kind of switch/relay/contactor between VFD and motor - and some (the better ones? Read "cost more...") are OK. Have to check with supplier to find out which is which!

Provided the VFD isn't outputting power and the motor is stopped then it's not a problem to switch between motors. I've done this with HY VFD switching between spindles using contactors without any problem.

Regards powering 2.2Kw motor with high startup load then I'd say it's do-able if VFD is setup correctly but better with larger VFD to give extra overhead and less stress on VFD.