Hello Marcio Marconi, There is not a script to run when changing your power connections.  You are correct in that you will want to power off and then make the changes using the install guide, then power back on and confirm all is seen correctly and powered back up correctly.  
I have a customer with ECS Gen3 EX300 wanting converting its current PDU (example: 3-phase Wye  to Single Phase). I did not found any documentation regarding this procedure. It is just powering off ECS, changing it (following Installation manual) and powering up? No script to run on ECS so it "knows" it has another PDU? I am asking this because for VMAX/POWERMAX it is necessary.
ECS Gen3 PDU conversion