Breaker for Soft Starter Feeder

First, learn something about the controlling codes. Then, don't ask other people to do your work for you.

• National Electrical Code has been adopted by the United States, Mexico, Costa Rica, Venezuela and Colombia
• IEC 60364 is used as a basis for electrical codes in many European countries
• Canadian Electrical Code published by the CSA is used in Canada
• British Standard BS 7671 is the set of wiring regulations used in the United Kingdom.
• NF C 15-100 (fr) is used for low voltage installations in France
• RGIE (fr) (Réglement Général sur les Installations Électriques) is used for installations in Belgium.

These are from Wiki. It took me 30 seconds to get them.

"Guest",

As a bit of palliative to lynlynch's rant;

You did not register nor state where in the world you are located, so any answer you get here is going to be potentially erroneous anyway. To get the most from this forum, register, state your location in your profile, and then... drum roll please.... give us ALL of the information you have. Assume that we know NOTHING about your application, because... WE DON"T!

All that said, as a grossly general rule there is no difference in selecting a circuit breaker for a soft starter than there would be in selecting one for a DOL starter, but as lynlynch implied, it will depend mostly on your local electrical code.

In the UK, British Standard 7671. It's all about the wiring...

Given the OPs use of "centre" instead of "center", I'd say that was a good bet.