Technical Specifications

FAQ

Q1: How does the self-powered feature of the REJ603 work?
A1: The REJ603 is designed to operate without an external auxiliary power supply. It derives the energy required for protection functions directly from the current transformers (CTs). During fault conditions, sufficient fault current provides the power necessary for the relay to detect abnormalities and initiate tripping actions. This design improves system reliability, particularly in remote substations and installations where auxiliary power may not be available.

Q2: What types of applications are suitable for the REJ603?
A2: The REJ603 is primarily intended for medium-voltage distribution networks, including feeder protection in substations, ring main units (RMUs), switchgear assemblies, and industrial power distribution systems. It is suitable for protecting overhead lines, cable feeders, and transformer feeders against various electrical faults.

Q3: What protection functions are available in the REJ603?
A3: The relay incorporates several essential feeder protection functions, including definite-time overcurrent protection, instantaneous overcurrent protection, and earth fault protection. These functions enable the device to detect overloads, short circuits, and ground faults, helping to minimize equipment damage and maintain network stability.

Q4: How does the REJ603 detect earth faults?
A4: The relay monitors residual or zero-sequence current to identify earth fault conditions. When a phase-to-ground fault occurs, an imbalance in the current system is created. The REJ603 detects this abnormal condition and initiates an alarm or trip command according to the configured protection settings, ensuring rapid fault isolation.

Q5: Does the REJ603 provide fault recording capabilities?
A5: Yes. The device records important operational and fault-related data, including fault type, measured current values, protection operation status, and event timestamps. These records assist maintenance personnel in troubleshooting, fault analysis, and verification of protection system performance.

Q6: Can the REJ603 perform tripping operations without an auxiliary power source?
A6: Yes. When the current transformers provide sufficient energy during fault conditions, the relay can execute protection calculations and issue tripping commands independently. This capability makes the REJ603 particularly valuable in installations where DC auxiliary supplies are unavailable or unreliable.

Q7: Can the REJ603 be integrated into modern automation systems?
A7: Depending on the selected configuration, the REJ603 can support communication interfaces for integration with SCADA systems, substation automation systems, and distribution management platforms. This allows operators to remotely monitor relay status, review fault records, and manage protection settings efficiently.

Q8: What are the main advantages of using the REJ603 in power distribution networks?
A8: The REJ603 combines protection, measurement, and monitoring functions in a compact and reliable design. Its self-powered architecture reduces dependency on auxiliary power systems, while its comprehensive protection capabilities enhance network security and operational continuity. The built-in event and fault recording features also support faster diagnostics and reduced system downtime.