GE SR750-P5-G1-S1-HI-A20-R

Product Description

The GE SR750-P5-G1-S1-HI-A20-R is a member of the renowned Multilin 750/760 family, widely recognized for its versatility in feeder and motor protection. This specific configuration, GE SR750-P5-G1-S1-HI-A20-R, is equipped with a comprehensive set of I/O options and communication protocols tailored for modern industrial power systems. It functions not only as a protection relay but also as a power quality monitor and a programmable automation controller, allowing users to implement custom logic directly within the device. The robust construction of the GE SR750-P5-G1-S1-HI-A20-R ensures reliable operation even in the harshest electrical environments, including high electromagnetic interference scenarios common in switchgear applications.

Technical Parameters

• Model Number: GE SR750-P5-G1-S1-HI-A20-R

• Series: Multilin 750 Series (Feeder Management Relay)

• Protection Functions: Overcurrent (50/51), Earth Fault (50N/51N), Under/Over Voltage (27/59), Under/Over Frequency (81), and advanced thermal protection.

• Inputs: 5A CT inputs (Phase and Ground) – Note: The “P5” designation indicates 5A phase CT inputs.

• Control Power: 125/250 V DC or 120/240 V AC – Note: The “HI” designation indicates high-voltage power supply.

• Communication Protocols: Modbus RTU, Modbus TCP/IP, DNP 3.0, and IEC 60870-5-103.

• Display: Large backlit LCD with user-programmable annunciator LEDs.

• Form Factor: Drawout case design for easy maintenance without rewiring.

Advantages & Features

• Comprehensive Protection Suite: The GE SR750-P5-G1-S1-HI-A20-R integrates over 50 protection elements, eliminating the need for multiple discrete relays in a single feeder circuit. This reduces panel space and simplifies wiring complexity.

• Advanced Programmable Logic: Unlike basic protection relays, this model features a built-in programmable logic controller (PLC) engine. Users can create custom logic schemes using the GE SR750-P5-G1-S1-HI-A20-R to handle complex interlocking, automation sequences, and alarm management without external controllers.

• High-Accuracy Metering: The device provides true RMS metering with Class 0.5 accuracy, enabling precise energy management, demand monitoring, and power quality analysis.

• Waveform Capture: In the event of a fault, the GE SR750-P5-G1-S1-HI-A20-R captures oscillography data, allowing engineers to analyze pre-fault and post-fault conditions for rapid troubleshooting and system optimization.

• Drawout Design: The relay chassis can be removed from its housing while the wiring remains intact, significantly reducing maintenance downtime.

Application Cases & Fields

The GE SR750-P5-G1-S1-HI-A20-R is widely deployed across industries requiring robust electrical distribution protection:

• Data Centers: Used in main switchgear and feeder breakers to ensure high availability and power quality monitoring for critical IT infrastructure.

• Manufacturing Facilities: Deployed in automotive assembly plants and heavy manufacturing to protect feeder circuits feeding motor control centers (MCCs) and welding equipment.

• Oil & Gas Refineries: Installed in substations to protect distribution feeders feeding process units, where the relay’s ability to withstand harsh environmental conditions is essential.

• Commercial Buildings: Utilized in large-scale commercial high-rise buildings for main incoming and feeder protection with integrated energy management capabilities.

Comparison with Competing Products

When compared to similar feeder management relays, the GE SR750-P5-G1-S1-HI-A20-R offers distinct advantages:

• vs. Schweitzer Engineering Laboratories (SEL) SEL-751: While the SEL-751 offers exceptional protection speed, the GE SR750-P5-G1-S1-HI-A20-R provides superior integration with GE’s legacy automation ecosystem. The programmable logic capabilities of the GE SR750-P5-G1-S1-HI-A20-R are generally considered more user-friendly for engineers familiar with ladder logic programming compared to SEL’s event-driven scripting language.

• vs. Siemens 7SJ62: The Siemens unit is a strong competitor in medium-voltage applications. However, the GE SR750-P5-G1-S1-HI-A20-R features a more comprehensive built-in data logging and waveform capture capability without requiring additional software licenses. Additionally, the drawout design of the GE SR750-P5-G1-S1-HI-A20-R offers easier field servicing compared to the fixed-case Siemens alternative.

• vs. ABB REF615: The ABB REF615 excels in IEC 61850 compliance. However, for facilities with existing GE or Modbus-based infrastructure, the GE SR750-P5-G1-S1-HI-A20-R offers a more cost-effective migration path with simpler configuration tools (EnerVista) that many engineers already possess.

Selection Suggestions & Precautions

When selecting the GE SR750-P5-G1-S1-HI-A20-R for your system, consider the following:

1. Verify CT Input Configuration: The “P5” in the model indicates 5A phase CT inputs. If your current transformers are rated at 1A, ensure you select the appropriate variant (P1 for 1A). Using the GE SR750-P5-G1-S1-HI-A20-R with 1A CTs without proper interface will result in inaccurate readings and misoperation.

2. Confirm Power Supply: The “HI” designation indicates a high-voltage power supply (125/250 V DC or 120/240 V AC). If your control power is 24-48 V DC, this unit is not compatible; you would require a low-voltage power supply variant (LO).

3. Communication Protocol Verification: While the GE SR750-P5-G1-S1-HI-A20-R includes Modbus and DNP 3.0 as standard, ensure your SCADA or PLC system supports these protocols. If IEC 61850 is a requirement, this model does not include it by default; a different variant with the “-G5” option would be required.

4. Firmware Compatibility: When commissioning the GE SR750-P5-G1-S1-HI-A20-R in systems with existing 750-series relays, verify firmware versions to ensure consistent settings file management using EnerVista software.

5. Environmental: While designed for switchgear environments, ensure the GE SR750-P5-G1-S1-HI-A20-R is installed in a panel with adequate ventilation, as internal temperature rise can affect long-term electrolytic capacitor life in the power supply section.