The micro-controller continuously monitors the magnitude of the phase current and
the neutral current .whenever the phase current or the earth current magnitude exceeds the
present value corresponding line / earth element will pick up and relay will trip after time
interval calculated by the selected IDMT curves. Whenever the fault level exceeds the
selected high set range, the relay will trip for high set, ignoring the selected IDMT curves. The
timer logic is processed and after comparison with set time schedules, tripping signals are
issued accordingly. There are two output relays , each output relay has two change over
contacts either for alarm or tripping. The output relays are programmable.
The relay rating (In) is field selectable either 1A or 5A. The relay has RS 485 com port which can
be used with modbus protocol for communication purposes.