The NJBK7 Motor Protection Relay provides comprehensive protection for AC motors (50Hz, ≤690V) including overload, blocking, phase failure, current unbalance, undercurrent, grounding, PTC temperature, and communication failure. It supports rated currents from 1A to 800A and features RS485 and 4-20mA analog interfaces for remote monitoring and control. Flexible Rogowski coils enable wide current range, high accuracy, and easy installation.