The CJD3 series electronic overload relay (hereinafter referred to as "relay") is mainly used to protect three-phase AC motors in low-voltage distribution systems with AC50H rated working voltage of 690V and below, and rated working current ranging from 0.8A to 450A. This series of relays is combined with AC contactors to form an electromagnetic starting device, which protects the motor from the hazards caused by overload and phase interruption.

The CJD3 series electronic overload relay does not require an external power supply and is a new type of electrical device based on microprocessor technology. It uses a microprocessor and related electronic circuits to detect the effective value of the current in the motor circuit, and then determines whether the motor is overloaded or disconnected. Based on the magnitude of the current, the delay time is determined, and when it reaches the tripping time, the tripping mechanism is driven to activate the auxiliary contacts and disconnect the main circuit of the contactor to achieve protection. Compared with traditional bimetallic thermal relays, it has the advantages of high detection accuracy, stable operating characteristics, and energy saving.
The product complies with IEC60947-4-1 and GB 14048.4 standards and has obtained the national mandatory product certification "CCC" mark.