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Star delta motor on a VFD

Star delta motor on a VFD

Star delta motor on a VFD

(OP)
How can I wire a star-delta motor ( six lead) to a VFD ? The motor has leads ( U1, V1, W1 , U2, V2 and W2.  thanks

RE: Star delta motor on a VFD

Wire it for the voltage corresponding to your grid voltage. That is the voltage (or, rather V/Hz) that your VFD will deliver. Not mentioning some special possibilities that exist.

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: Star delta motor on a VFD

There are a lot of inter-dependent parameters. What are the motor nameplate voltages in star and delta, and what is the VFD output voltage? Also what is the VFD maximum output frequency and what is the motor nominal frequency (or rated speed)?
  

----------------------------------
  
If we learn from our mistakes I'm getting a great education!
 

RE: Star delta motor on a VFD

Unless you have something special, six-lead motors (suitable for star-delta starter) are designed to run in delta. Star connection is only used during starting on a star-delta starter.

If so, you want to wire it in delta for VFD application.

Rafiq Bulsara
http://www.srengineersct.com

RE: Star delta motor on a VFD

I'll politely disagree with Rafiq, at least for motors in the IEC world. Below 7.5kW motors are typically 230V delta / 400V star. Above 7.5kW motors are typically 400V delta / 690V star.
  

----------------------------------
  
If we learn from our mistakes I'm getting a great education!
 

RE: Star delta motor on a VFD

ScottyUK:

No offence taken. All information is useful.

I would think dual voltage rating would be posted on the name plate. Perhaps that is what the OP meant by star-delta motor, then what you said is absolutely correct.

If the name plate indicates single voltage and the motor has six leads, it is usually meant for delta. At least that what I had come across in six years of experience in the IEC/India in the 80's. I thought by star-delta motor the OP meant a motor used on a star-delta starter, which probably was not correct.

Thanks

 

Rafiq Bulsara
http://www.srengineersct.com

RE: Star delta motor on a VFD

Shall we sum it up in one sentence?:
Wire it for the voltage corresponding to your grid voltage.  

Gunnar Englund
www.gke.org
--------------------------------------
100 % recycled posting: Electrons, ideas, finger-tips have been used over and over again...

RE: Star delta motor on a VFD

IEC, Star:delta is normally used for a 1.73:1 voltage adjustment.
NEMA Star:delta is normally used for starting, star to start, delta to run.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Star delta motor on a VFD

If the OP can post the relevant details of the motor and the drive, then may be so many posts won't be needed to read his mind. :)

Muthu
www.edison.co.in

RE: Star delta motor on a VFD

Well said, Muthu. Gunnar has also summed it up concisely.

Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: Star delta motor on a VFD

If you are going to remove three of the cables (leaving three), then make sure you have the correct cross-section for the load/distance required.
  

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