EMS as defined by Progressive Industries = Electrical Management System
"Progressive Industries Portable Electrical Management Systems (EMS) provide full RV protection against all adverse power conditions." , what is commonly called a "surge protector". It does not manage energy use.
EMS as defined by the rest of the world = Energy Management System, manages loads to keep circuits from overloading.
I believe the "open ground" discussion in this thread is related to the unfortunately named Progressive Industries EMS, which is really a "surge protector", another bad name for a power quality monitoring and protection device. Nothing to do with the other EMS, Energy Management System.