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No, not a problem from the standpoint of the motor. Just do as you said, connect to the motor in the Delta pattern only.


Power system capacity and torque issues related to the power train components and load are a different story, but you didn't post enough information to assess this any further. If those are issues for you, a Solid State Soft Starter is a better choice than Start-Delta anyway, and it would connect to the motor in exactly the same was as DOL.

"He's not dead, he's just pinin' for the fjords!"
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Hello Bakia


Welcome to the forum


Technically, there are no problems connecting the motor in Delta and using the DOL starter, but there are consequences that do need to be considered.

The strt current will be very high, typically in the region of 600 - 800% of the rated current of the motor. In some installations, that is not a problem, but in others it can be a major issue causing voltage drop and voltage fluctuation problems, and in some regions, there are requirements limiting the amount of starting current you can draw.

Another issue is the start torque magnitude. This can cause mechanical issues depending on the driven load.

So, the questions that I would ask are:

Are you alowed to DOL start that motor?

Is the supply strong enough to DOL start that motor with out voltage disturbance issues?

Is the machine robust enough to withstand the DOL start torque?


Best regards,

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Dear Bakia,

rarely there is the need to start a motor without his load.

Therefore you must consider all the typical needs of your load (inertia, friction, effective load, peaks of requested torque).

Starting DOL a small motor unloaded on a strong line is possible, starting DOL a big motor with high friction and high inertia is impossible.


If you need a reply for a specific application, please add more data.




Mario Maggi - Italy - http://www.evlist.it - https://www.axu.it

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