VFD were used in the 1930s
of course werner von siemens!

around here there oldest drives I have ever seen are Graham drives from the late 70's early 80's.

i have one graham drive only 25 hp
it is 6x6x2!!!

Quote Originally Posted by ncboston View Post
VFD's have been around for quite a while. At least 15 that I know of. I believe the ECM motors are fairly new.