Two of three phase motor currents are monitored by current
transformers. External CTs are required for currents more than
60Amps. The internal solid state circuitry compares with the preset
current level. When load currents exceed the preset trip level, red
LED illuminates, and after the preset time, the device trips, and
changes internal SPDT relay contacts. Red LED remains illuminated
indicating an overload trip has occurred and Green LED (PWR) goes
off. Until manual or remote electrical reset by interrupting
supply, is initiated.
If load current falls off below set point before the preset delay,
device resets trip timer. With the visual aid of LED, flashing at
100% of preset load, actual load currents can be determined without
the aid of Ammeter. Test button provides the means of testing
service-worthiness and integrity of the device. Internal relay is
energized in normal operation condition (fail-safe) and will not
become ready mode with either supply lost or own failure.
Starting delay time range: 0.2-30 seconds.
Trip delay time range: 0.2-10 seconds. Maybe used as electronic
shear pin by setting trip time to minimum.