Connecting 424 to a VFD without a 407!!!

[Scott5867]

I have looked all over the place on this forum and cannot seem to find a connecting diagram or instruction to connect the 424 to a 2.2kw vfd. everyone is using a 407 to make the connection. If the 424 puts out a pwm signal that is capable of controlling the spindle why is everyone using the 407 to do the same thing. if anyone knows the connections that need to be made for just connecting the pmdx-424 to a 2.2kw huanyang VFD i would appreciate it.

[12strings]

Generally, using a 407 leaves the normal PMDX-424 output signals available for other purposes.  It also provides isolation between the VFD and the 424 (and whatever else you can connected to the 424).  This is both electrical isolation and (some) electrical noise isolation.

Some VFDs have funky ground schemes where the "gnd" is actually one of the AC lines.  I don't know about your VFD, but several years ago I blew up a VFD by connecting its "gnd" to the digital ground on my breakout board.  POOF!

For the cost of a PMDX-407, I wouldn't risk it.

[Scott5867]

That’s the best reason I have so far on any forum as to why to use a 407 so far. Thanks