Product Description

Overview

The RET316*4 (HESG448750M2) is a high-performance numerical relay designed for the protection, monitoring, and control of power transformers. Part of ABB’s 316 series, this relay provides reliable, fast, and selective protection for two-winding and three-winding transformers, including autotransformers and generator-transformer units. Advanced digital signal processing (DSP) ensures accurate fault detection and immunity against inrush currents or external disturbances.

Technical Specifications

• Manufacturer: ABB

• Model: RET316*4

• Order Number: HESG448750M2

• Product Type: Numerical Transformer Protection Relay

• Power Supply: 24 V DC standard, 110–240 V AC/DC variants available

• Operating Temperature: -20°C to +55°C

• Ingress Protection: IP20 (standard), IP54 front panel optional

• Mounting: Horizontal or vertical, derating may apply

• Dimensions (HxWxD): 135 × 67.5 × 28 mm

• Weight: 1.5 kg

• User Interface: CAP2/316 software, menu-driven, Windows-compatible

• Communication Protocols: IEC 61850, IEC 60870-5-103, Modbus®, DNP3, Profibus DPV1 (via SPA-ZC 302)

• Interfaces: 3 serial ports for local PC, station control system, and process bus

Key Features

• Differential Protection (87T): Fast, selective tripping for internal faults with inrush restraint.

• Restricted Earth Fault (REF): Detects sensitive internal ground faults near transformer neutral.

• Overcurrent & Earth Fault: Multi-stage protection with directional and non-directional options.

• Thermal Overload Protection: Monitors transformer winding heating to prevent insulation damage.

• Over-excitation (V/Hz): Safeguards transformer core during voltage or frequency excursions.

• Advanced Logic: Multi-layer programmable logic with timers, flip-flops, and custom schemes via PCM600.

• High-Speed Operation: Typical differential trip times under 25 ms for immediate fault clearance.

• Self-Monitoring: Continuous internal diagnostics for reliability and operational readiness.

• Data Logging: Event and disturbance recording for post-fault analysis.

Applications

• Substations: Protection of medium and high-voltage transformers.

• Power Plants: Generator-transformer protection for reliable energy delivery.

• Industrial Power Systems: Safeguarding autotransformers and critical distribution transformers.

FAQ

Q: Is the relay suitable for three-winding transformers?
A: Yes, RET316*4 protects two-winding and three-winding transformers, including generator-transformer blocks.

Q: Can it communicate with modern substation protocols?
A: Yes, supports IEC 61850, Modbus®, DNP3, IEC 60870-5-103, and Profibus DPV1.

Q: How does it handle inrush currents during transformer energization?
A: Built-in inrush restraint logic ensures stable operation without false trips.