Description

760-P5-G5-S5-A20-R  GE 760 feeder protection relay

Protection Functions

• Overcurrent Protection: Equipped with two-phase Time Overcurrent (TOC) elements, each phase integrated with a level detector. It allows setting pickup current levels for tripping, alarming, or control, with 15 curve shapes selectable and parameters like curve multipliers adjustable. Additionally, overcurrent elements support primary and backup protection.
• Frequency Protection: Includes 2 underfrequency elements (81U), 2 overfrequency elements (81O), and 4 frequency decay df/dt elements (59/81). It enhances network stability using voltage or frequency technologies, providing backup protection for generators and other frequency-sensitive power equipment, and directly tripping circuit breakers.

Equipment Management Functions

• Tracks operation counts of main circuit breakers, calculates contact wear of each phase, detects circuit breaker faults, and monitors trip coils, facilitating maintenance and management of circuit breaker equipment.

Metering Functions

• Features precise built-in metering without auxiliary devices, reducing costs. It enables comprehensive metering including demand and energy.

Communication Functions

• Equipped with multiple network interfaces (Ethernet, RS232, RS485, RS422 ports), supporting protocols like ModBus RTU, TCP/IP, and DNP3.0. It connects with distributed control systems, PLCs, or SCADA systems for local/remote control.

Event Recording and Fault Analysis Functions

• Supports IRIG-B time synchronization, with event reporting, waveform capture, and data logging functions. It accurately records event sequences and timestamps, and logs electrical waveforms during faults for efficient fault analysis, reducing troubleshooting time and maintenance costs.

Other Functions

• Drawer-type structure minimizes replacement time; optional conformal coating adapts to chemically corrosive and humid environments, extending service life; built-in simulation simplifies testing.

Practical Application Cases

Medium and Low Voltage Distribution System Protection

• In the medium-low voltage distribution system of a commercial complex, the GE 760-P5-G5-S5-A20-R digital feeder protection relay provides backup protection for busbars, transformers, and transmission lines. Its overcurrent protection detects overloads and short circuits in real time. By configuring Time Overcurrent (TOC) and Instantaneous Overcurrent (IOC) elements, it effectively safeguards distribution lines and connected electrical equipment. The precise built-in metering helps property managers monitor power consumption in each circuit in real time, eliminating the need for additional metering devices and reducing costs.

Distributed Energy Grid Connection Protection

• In the 5.98MW distributed photovoltaic 10KV grid-connected system of Leimeng (Hubei) Intelligent Equipment, protection relays similar to the GE 760 series ensure system safety. The relay monitors parameters like voltage and current of the photovoltaic grid-connected lines in real time. When grid faults are detected, it quickly disconnects the power generation system from the public grid. The frequency protection function monitors grid frequency fluctuations, ensuring the photovoltaic system operates safely during frequency anomalies to avoid equipment damage and further impacts on the grid.

Motor Protection in Industrial Automation Systems

• In a chemical enterprise’s production workshop, the GE 760-P5-G5-S5-A20-R protects equipment such as reactor agitator motors and centrifuge drive motors. Using its ground fault protection, it real-time monitors zero-sequence current in motors, cutting off faulty circuits promptly to prevent hazardous accidents (e.g., explosions due to insulation failure). The relay’s event recording and waveform capture functions log relevant electrical waveforms and event sequences during motor faults, assisting technicians in quickly locating fault causes and reducing troubleshooting and maintenance costs.