Over- / Under-Power Relays PTG7100
The PTG7100 relays measure Active Power (based on nominal voltage) and are designed to perform one of two functions:

PTG7111 is a directional over-power relay designed to protect diesel-driven alternators against motoring and is therefore effectively a reverse-power relay (ANSI code 32P or 32RP)

PTG7113 is an under-power relay designed to automatically start and stop generators in a parallel generation network (ANSI code 37P)

A full brochure is available on the homepage for Static relays.