The Mentor-12 Universal Three-Phase Protective Relay Test Set. It is a versatile and modular system designed for both type and field testing of electromechanical and digital protection relays. The unit can be operated as a stand-alone device via its built-in touch screen or controlled by a PC, and its expandable “plug & play” design allows for a variety of configurations, including the ability to upgrade to up to 12 outputs. Key features include advanced test functions like Fault, Ramp, and COMTRADE transient playback, making it suitable for comprehensive analysis and simulation in power substations.