Overview of SR Series Relays

The SR series relays are microprocessor-based multifunction protection devices designed for industrial and power systems, including motors, generators, transformers, and feeders. They integrate protection, control, monitoring, and measurement functions into a single unit, eliminating the need for multiple discrete components.

Main Applications and Models

• 735/737: Feeder protection
• 750/760: Comprehensive feeder protection
• 469: Motor protection
• 745: Transformer protection
• 489: Generator protection

Key Features and Advantages

• User Interface: High-quality human-machine interface (MMI) with large backlit LCD capable of displaying 40 characters, readable under direct sunlight. Includes full digital keypad and navigation keys (except 735/737).
• Accurate Measurement Under Disturbance: Models 750, 745, and 489 track power system frequency and adjust sampling rates to maintain precision during severe system disturbances.
• Modular Design: Draw-out structure allows quick module replacement, reducing downtime.
• Auxiliary Equipment Monitoring: I/O monitoring extends auxiliary device operational time.
• Ease of Use and Installation: Uniform front panel programming and cutout sizes (except 735/737) simplify installation and operation.
• Fault Diagnosis and Maintenance: Features IRIG-B time synchronization, event reporting, waveform capture, and data logging (except 735/737) to reduce troubleshooting time and maintenance costs.

Monitoring and Measurement Capabilities

• Event recording and waveform capture
• Self-diagnostics and demand measurement
• Analog and digital inputs for parameters such as oscillation, pressure, temperature, and breaker status
• Analog outputs for real-time process control and PLC integration

Communication Interfaces and Protocols

• Three independent communication ports (except 735/737): RS232 (front panel), RS485, and RS485/RS422 (rear panel)
• Optional 10BaseT Ethernet interface (models 750/760, 469, 489, 745) supporting 10 Mbps LAN/WAN connectivity
• Supported protocols include ModBus RTU, TCP/IP ModBus RTU, DNP 3.0 Level 2, and optionally DeviceNet (469)
• All communication interfaces can operate simultaneously

Software Support - EnerVista LaunchPad

• Free configuration and setup software included with SR relays
• Enables quick relay setup, event and waveform data retrieval, and viewing
• Provides access to product manuals, technical specifications, and firmware updates via internet and email notifications
• Includes simulation features for training and testing

Product Upgrade and Longevity

• Flash memory technology (except 735/737) allows firmware upgrades without removing the relay
• 735/737 require EEPROM replacement for upgrades
• Optional conformal coating extends relay life in chemically corrosive and humid environments (except 735/737)

Design and Safety Features

• Draw-out relay design with automatic CT secondary shorting upon removal to prevent dangerous high voltages
• Standardized dimensions across models 489, 745, 750/760, 735/737, and 469, with differing terminal configurations

Technical Documentation and Support

Electronic technical specification guides are available online at www.GEMultilin.com/specs or via fax/email request.

Summary

The SR series relays provide a comprehensive, modular, and user-friendly solution for protection and control in industrial and power systems. Their advanced measurement capabilities, flexible communication options, and integrated software tools facilitate efficient system monitoring, fault diagnosis, and maintenance, while their robust design ensures reliability in harsh environments.