600V Inverter and 220V Ac motor

[karlag]

OK, it is done. After 600v inverter(Mitsub. E-500) was install 4KVA auto transformer and 220V Ac motor( 3HP 4.3A) . All parameters was set and after first try inverter fell to overload. I run auto tunning and all went fine.

 

[DickDV]

Just because the motor shaft turns, things are not necessarily fine. You probably should do some performance evaluation over the whole desired speed range first. Especially watch for rapid falloff of motor torque as it slows down and also transformer heating as the frequency falls.

If you get past those tests, call it good and "hurrah!"

 

[karlag]

Just because the motor shaft turns, things are not necessarily fine. You probably should do some performance evaluation over the whole desired speed range first. Especially watch for rapid falloff of motor torque as it slows down and also transformer heating as the frequency falls.

If you get past those tests, call it good and "hurrah!"

Thanks! I will. Had no chance to run motor under the load due to mechanical problems( you know what I mean)

 

[shooter]

you should not need a transformer:
use the maximum output voltage setting and put it on 400 volts.
put the motor in star configuration not in delta this way it can take the 400 volt.
a normal motor is 400/230 volt for example.
on most vfd it is possible to put a smaller motor on.
the use of a transformer will work until power is asked.

 

[DickDV]

shooter, this is a North American motor and the wye/delta determination is made up inside the motor. You don't have the option of changing delta to wye or vice versa as you do with many IEC motors.

And anyway, that gets you to 400VAC. What about the other 200VAC to get to 600VAC?

 

[milmat1]

shooter, this is a North American motor and the wye/delta determination is made up inside the motor. You don't have the option of changing delta to wye or vice versa as you do with many IEC motors.

And anyway, that gets you to 400VAC. What about the other 200VAC to get to 600VAC?

He is saying set the VFD's Max V-OUT to 400 VAC

 

[DickDV]

millmat, theoretically we could set the drive max output voltage to 220V but check out my earlier posts in this thread concerning drive output pulse voltage.

Regardless of what the equivalent lower AC voltage the drive is limited to, the pulses are still 850VDC+ high plus any ringing voltages. That's too high to expect long life out of 230VAC insulation.

 

[ToolGuyFred]

millmat, theoretically we could set the drive max output voltage to 220V but check out my earlier posts in this thread concerning drive output pulse voltage.

Regardless of what the equivalent lower AC voltage the drive is limited to, the pulses are still 850VDC+ high plus any ringing voltages. That's too high to expect long life out of 230VAC insulation.

Don't underestimate this phenomenon. When I worked for Mitsubishi as a drives application engineer, we had a customer with motors in a HVAC application driven via our drives failing after only 4-6 weeks. Turned out that although they were rated at 400V for DOL use, the insulation was only rated at about 800V and inverter use could have been subjecting them to over 1100V (these were on long cables and voltage doubling due to ringing is not uncommon). (These were far eastern copies of Siemens motors.) We suggested they either fit motors with higher voltage rated insulation or inductive filters between the drive and the motor. Don't know what they did in the end as they never got back to us after we'd identified the problem. (They must have fixed it though - the job and the end-user customer were both too big to ignore.)