My service is 120/240 volt 225 amp mains 1 phase
Need to hook up 2 plugs 3 phase

OK, I hope that works out for you.

What you want to do cannot be done. To power 3-phase outlets you have to have a 3-phase service. Are you confusing your terms or is that what you really need?

You cannot convert a single phase (actually a "split" phase) to three phase at the panel.

You need to contact your power company a determine if they will allow your service to be changed to three phase. Also, your entire electrical panel will have to be changed out for a three phase panelboard.

This is a costly project are you sure you want to do this.