GE Multilin 750/760 Feeder protection system

GE Multilin 750/760 Feeder protection system

Feeder protection system 

The 750/760 Feeder Protection System is a digital relay intended for the management and primary protection and control of distribution feeders. This easy to use relay provides comprehensive protection functions for feeders and back up protection for bus, transformers and transmission lines in a draw out construction and at a reduced product life cycle cost.

Key Benefits 

• Easy to use Feeder Protection System supported by industry leading suite of software tools 

• Accurate built-in metering functions - Eliminates auxiliary metering devices and reduces cost 

• Improve uptime of auxiliary equipment - I/O monitoring 

• Reduce troubleshooting time and maintenance costs - IRIG-B time synchronization, event reports, waveform capture, data logger 

• Minimize replacement time - Draw-out construction 

• Simplify testing - Built in simulation features 

• Cost effective access to information. Supports industry protocols such as DNP & Modbus. Includes an optional 10MB Ethernet port for system integration • Complete asset monitoring - Analog I/O, Full metering including demand & energy 

• Leading edge technology - Flash memory for product field upgrade 

• Extended life - Optional conformal coating for chemically corrosive and humid environments 

• Globally accepted ensuring adherence to international codes and standards

Applications 

• Primary protection and control for distribution feeders on solidly grounded, high impedance grounded or resonant (Peterson Coil) grounded systems 

• Bus blocking/Interlocking schemes 

• High-speed fault detection for arc flash mitigation 

• Throw over schemes (bus transfer scheme applications) 

• Load shedding schemes based on voltage and frequency elements 

• Back-up protection for transmission lines, feeders and transformers 

• Distributed Generation (DG) interconnect protection

Time & Instantaneous Overcurrent 

The 750/760 has two phase TOC elements with level detectors for each phase. The 750/760 also has two overcurrent elements most commonly used for primary and back up protection. Each TOC element has the following programmable characteristics: 

• Pickup current level for trip, alarm, or control 

• Choice of 15 curve shapes (including FlexCurves) and curve multipliers 

• Instantaneous or linear reset time characteristic 

• Voltage restraint

Frequency Protection 

750/760 provides functionality to improve network (grid) stability using voltage or frequency based techniques. Also allows to provide back up protection and trip breakers directly when protecting generators and other frequency sensitive power equipment. 

• 2 Under-frequency elements (81U) 

• 2 Over-frequency elements (81O) 

• Frequency decay: 4 df/dt elements (59/81) 

• 2 Undervoltage elements

Equipment Management 

The following comprehensive features in the relay allows to manage the primary breaker: 

• Trip counter to keep track of number of operations 

• Per-phase breaker contact wear calculations for maintenance 

• Breaker failure detection 

• Trip coil monitoring