Can we customize the nominal voltage in STS400 ?

Yes , We can  customize the nominal voltage in STS60. Follow the below steps to customize. 
​1 - Press the menu button.
2 - Select "Setup", then "Customization" using the function buttons marked up arrow or down arrow. 3 - Confirm the order by pressing the function button marked as Enter 4 - Enter the password.  From the screen menu :
1 - Select the source to be configured
2 - Change the parameter(s)
3 - Save the customization settings