The first numerical relays were released in 1985. A big difference between conventional electromechanical and static relays is how the relays are wired.
The first numerical relays were released in 1985. A big difference between conventional electromechanical and static relays is how the relays are wired.
We provides directional over current protection for power systems. Relay operating time is determined by selecting definite time characteristics or one of the four inverse time characteristics i.e. (3s normal inverse, 1.3s normal inverse, very inverse and extremely inverse). The operating region is defined by the characteristic angle selected. The relay measures the current and voltage from each of the phases and if the phase angle in the operating zone of the relay, then the relay extends trip signal.
