overload setting on big motor,s

A better choice of CT would be 500/5. If the overload sensor is applied to the CT secondary, then to match the motor FLA of 386, it should be set at 386 × 5/500 = 3.86 A.

[Editorial note: plurals such as "motors" do not ordinarily take either a comma (,) or an apostrophe (').]

You should probably get some local help who knows something about electricity.

It worries me that you are asking these types of questions on a forum where no one knows that your information is valid and you don't know the qualifications of the person careless enough to give a novice advice.

Seek professional help, or you could end up permanently dead. Or worse yet, you could kill somebody else.

Normally OL relay is sized according to phase current (386/1.732) which is approximately about 180A(check). CT should be 200/5.

Hire a qualified Electrical Engineer, who will use the local equivalent of British Standard 7671.