This book explains the replacement of the existing generator protection system of a gas turbine generator, by a digital multifunction generator protection relay: SIEMENS, Type: 7UM62255EB093CG0 with a 7XT71 controller unit, 7XR6004 resistor unit for rotor faults, and a 3PP1326 resistor unit for excitation faults. A step-by-step description of the functions and configuration of the protection equipment is given, with a brief explanation of installation and commissioning.