GE MULTILIN | SR750-CASE 750-P5-G5-S5-LO-A20-G-E FEEDER MANAGEMENT RELAY

The GE Multilin SR750 is a sophisticated, numerical feeder management relay designed for the protection, control, and monitoring of distribution feeders. As part of the SR 750/760 family, this device provides comprehensive protection for utility and industrial power systems, ensuring the integrity of electrical assets against faults such as overcurrent, short circuits, and ground faults.

Product Specifications

Application Fields

The 750 series is engineered for high-reliability environments:

• Utility Distribution: Primary protection for medium voltage feeder circuits.
• Industrial Facilities: Motor control centers and protection of secondary substations.
• Oil & Gas/Mining: Critical power infrastructure monitoring in harsh conditions.
• Data Centers: Ensuring stable power distribution and rapid fault isolation.

Product Usage Instructions

1. Mechanical Mounting: The SR750 utilizes a “draw-out” design. Ensure the case is securely mounted to the panel/rack, allowing space for the handle to be engaged or disengaged.
2. Wiring: Ensure current transformer (CT) secondary circuits are properly shorted before installing or removing the relay to prevent high-voltage buildup. All control inputs and outputs must be verified against the specific wiring diagram for the S5/A20 configuration.
3. Software Setup: Use EnerVista 750/760 Setup software to configure relay setpoints. Connect via the front-panel RS232 port or the rear RS485 port.
4. Testing: Before commissioning, perform a primary or secondary injection test to verify protection element pickup levels and trip times.

Q&A: Frequently Asked Questions

Q: What do the codes like P5, G5, and S5 mean in the model number?

A: These represent specific hardware options. For instance, they define the nominal CT/VT ratings, communication protocols (like Modbus/DNP3), and the type of digital I/O modules installed in the specific unit. Always reference the order code manual for your specific unit.

Q: Can this relay communicate with my SCADA system?

A: Yes. The SR750 supports industry-standard protocols such as Modbus RTU, DNP 3.0, and IEC 60870-5-103, allowing it to easily integrate into modern SCADA or DCS networks.

Q: How does the “Draw-out” design improve maintenance?

A: It allows the technician to remove the relay electronics from the case without disconnecting any field wiring, significantly reducing downtime during replacement or calibration.

Recommended Inventory Products

If you are supporting legacy SR750 systems, these related items are highly recommended for your spares inventory:

1. GE Multilin 750/760 Replacement Case
2. GE Multilin SR760 Feeder Management Relay
3. EnerVista Communications Software Suite
4. GE B30 Bus Differential System
5. Siemens 7SJ600 Overcurrent Relay
6. ABB REF615 Feeder Protection Relay
7. Schneider Electric Sepam Series 40
8. Test Plugs (Flexitest) for draw-out cases
9. RS485 to Ethernet/Fiber Converters
10. Replacement CT Shorting Terminal Blocks