# Running a 3ph motor rated for 380v star on 220v delta

I've got an old Soviet 4kW motor, made in 1983. The dilemma is that the nameplate info states a Y-connection/380v/8.7amps and I want to run it on delta using my VFD which produces 3ph 220v. All my other motors are rated for both 220v delta & 380v star and I've never had a situation like this, so I was wondering what are the dangers of running a motor on delta if that's not specified?

• probably the soviets had no need to use the motor in that configuration, so they didn't put it on the boilerplate. Apr 29, 2018 at 9:04
• Are you sure about your inverter? I guess it's 220V L-N and 380V L-L, not vice versa. The motor seems to be a 660V/380V type from your description. Apr 29, 2018 at 9:11
• The VFD produces 3ph 220 line-to-line voltage out of a 1ph 220v L-N from the mains. The only voltage that's specified on the plate is 380v Y-connected. Apr 29, 2018 at 9:35
• @IvanP.: That sounds right. The input is rectified to give a DC bus of $\sqrt 2 V_{IN}$. This determines the max line-line output of $\frac {1}{\sqrt 2} V_{BUS}$. With single phase in you can get the same voltage but phase-phase on the output. Apr 29, 2018 at 9:35
• Then, your inverter is a 220V/130V type. I don't see how this matches either 380V/220V nor 660V/380V motors. Apr 29, 2018 at 9:45