Can I Star-Delta my motor

Hi, we are having problems with a motor on a tyre shredder that seems to be droping out, we have tried many things to find the cause but to no avail, I have a feeling it is the softstarter (a Powerboss) and plan to try to prove/disprove that its the softstarter by temporarily replacing with a star-delta. Im assuming I will need to run another set of leads out (as only 3 + Earth at present) but do I need to change terminal wiring in motor terminals, and a bigger question can any 3 phase motor be wired in star-delta??

thanks for any help, leon.

A three lead single voltage motor can not be connected star-delta because you don't have both ends of the three coils available in the junction box. The same is true of dual voltage nine lead motors.

You will need a six lead or twelve lead motor. You might already have that but probably not.

...and a bigger question can any 3 phase motor be wired in star-delta??

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I can answer that one - No, not just any 3-phase motor. You need 12 leads coming out of the motor to get Star-Delta, but here in the US, a commonly used dual-voltage type only has 9 of the 12 leads brought to the outside (3 coils have one side connected together internally).

Do I need to change terminal wiring in motor terminals...?

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Yes, you will need to reconfigure the motor leads.

Describe more about "motor dropping out" ie in first five second, five minute, or five hours.

Also tell us more about motor - give us all that trivial nameplate data - better yet send photo.

Reading between lines I think you are saying it is dropping out while in startup. Unless you have a whole bunch of big relays on the shelves star delta costs may add up to more than the cost of a soft start.

I wonder if a bypass relay on soft start may help problem. This would require careful evaluation especially since you seem to be concerned with starting current.

Dan Bentler

Is this an existing installation that has worked in the past or is it new?