NRE8 series electronic overload relay (hereinafter referred to as relay) is mainly used for AC 50/60Hz, rated working voltage below 690V, current is in the circuit within the calibration current range of the casing calibration, for three-phase motor overload and phase failure protection. This relay is a new type of energy-saving, high-tech electrical appliance that uses a microcontroller. Corresponding to the same specification bimetal thermal relay can save more than 80%. The relay uses a microcontroller to detect the current waveform and current of the main circuit to determine whether the motor is overloaded or phase-out. When overloading, the microcontroller determines the length of the delay by calculating the overload current multiplier. When the delay time is up, the normally closed contact is opened by the trip mechanism, and the normally open contact is closed. The microcontroller reduces the delay time during phase loss. Meet the standards: GB/T 14048.4, GB 14048.6, IEC 60947-4-1, UL508. This product can be installed in parallel with the corresponding AC contactors such as NC1, NC7, NC8 and NC2.