Minilec [india] pvt ltd offers system monitoring relays. The i-phase current monitoring relays measure current through 1 or 5a external current transformer [ct] for under and over current conditions. The setting range covers 50 to 140% of input ct rating. The earth fault relay is best suitable for monitoring earth fault conditions for motor/pump loads with selectable setting range from 100 ma to 5 a. These are used with cbct or 3 normal cts. For monitoring line frequency variations or for monitoring generator over speed the frequency relays are best suitable for under/over frequency conditions. For monitoring the reverse flow of power from the generators or when motors act as generators reverse power relay find the application. They sense the direction of power by sensing the reverse current. To monitor no load or under/over power conditions of pumps or motors or/and power monitoring relays are to be used it is best suitable for balanced 3-phase 3-wire pump loads for no load or belt failure or dry run and jamming or overload conditions.
