16 years ago
rated for 3/4HP 3phase motor.
I am using 220v AC single phase residential service, and the above unit
is configurred for either single or 3phase input (seems to be a
So, I go onto eBay looking for a larger capacity unit to drive a
different 2HP 3phase motor I want to use.
Almost every listing is for units which specifcally state "3phase
Now , with my limited knowledge of the workings of a VFD, I have
gleened from other threads, that the input stage simply rectifies the
input through a single or 3phase diode bridge, then takes the DC and
does it's magic and produces a variable frequency three phase output at
the same voltage as the input, which in my case is 220v.
I realize that just feeding from one phase would derate the ultimate
capacity, but how can you determine if a 3phase unit will or will not
function when only a single phase supply is used???
BTW, the above Toshiba unit works quite well on a single phase 220v
motor, with the other two legs not connected, even tho there is no
stipulation that this configuration is acceptable.
Any insight would be greatly appreciated
Stew Corman from sunny Endicott