Motor connected in star not delta

[Jimsparky]

I had a similar one to this yesterday, 11 kw was wired in star delta and we were putting a VSD on it. Nothing on the plate about wether it would run in star or delta. Possibly naively i assumed delta for the size of the motor but it wouldn't run. Changed it to star and run a treat.

Is there any particular rule for sizes of motor and star or delta ?

 

[Darkwood]

Think you need to review the motors sticky we have on this forum and understand the the different methods of connection to single voltage, duel voltage motors.... doing what you are doing will be a costly lesson to learn, connecting the motor up correctly is crucial and just because it runs dosn't mean you got it correct, an incorrect connection can overvoltage the windings, reduce the torque by a factor of 3 etc etc but many variables can mask the issue like VSD speed settings etc.
I wouldn't in your shoes be venturing down this avenue until you understand motors a little more.. please take as constructive advice

 

[Darkwood]

Did you have 1 voltage rating on the plate?
What info did the plate give you if any?

 

[Knobhead]

I had a similar one to this yesterday, 11 kw was wired in star delta and we were putting a VSD on it. Nothing on the plate about wether it would run in star or delta. Possibly naively i assumed delta for the size of the motor but it wouldn't run. Changed it to star and run a treat.

Is there any particular rule for sizes of motor and star or delta ?

Unfortunately no. This is why the lads have asked for the motor plate details. I covered motor voltages in the motor section, it may take a bit of finding, nothing is in order.

 

[billyfender]

On certain invertors you have to program in the nameplate details. If you program in that the motor is star and it is actually connected delta have seen before that the motor struggles to run.

 

[Darkwood]

On certain invertors you have to program in the nameplate details. If you program in that the motor is star and it is actually connected delta have seen before that the motor struggles to run.

Yes agree with the motor nameplate values but i yet to have an inverter ask if star or delta, as motor configerations vary this wouldn't be any use to the inverter, its up to the engineer/electrician to ensure output voltage matches winding configeration.
690 Y --- 400v D
400 Y --- 230v D
2 common duel voltage motors from different parts of the world but require the opposite connection for 400v.