Key Technical Specifications

Product Model: F650-B-F-J-F-2-G-1-HI-E
Manufacturer: GE
System Platform: Multilin F650 Feeder Protection System
Nominal Control Power Supply: 24–250 VDC / 48–240 VAC (wide-range utility grade)
Current Inputs (CT): 1 A / 5 A selectable
Voltage Inputs (VT): 63.5 V / 110 V standard sensing range
Protection Functions: 50/51, 50N/51N, 67/67N, 27, 59, 81, breaker failure, load encroachment
Directional Elements: Full quadrant directional overcurrent algorithms
Digital I/O: Expanded DI/DO set as per “B-F-J-F-2-G-1” configuration
Communication Interfaces: RS485 + Ethernet (copper), redundant ports model-dependent
Supported Protocols: IEC 61850, Modbus TCP/RTU, DNP3, IEC60870-5-103
Recording Capability: SER, oscillography (COMTRADE), event/fault logs
Logic Engine: Programmable automation logic with GE FlexLogic™
Operating Temperature: –40°C to +70°C
EMC/Environmental Standards: CE, IEC 60255, utility-grade surge withstand
Safety & Compliance: IEC/EN 60255-26, 60255-27, UL/CSA where applicable

Technical Architecture & Functional Positioning

The relay occupies a core role in the protection and control layer of a modern electrical distribution system. Within the Multilin architecture, this unit functions as both a feeder protection element and a bay controller, enabling integrated operation of protective, metering, logic, and control functions. Its electrical inputs are designed to interface directly with CTs and VTs, while its output contacts drive circuit breakers and interlocking schemes.

Internally, the relay uses a fast protection processor dedicated to protection decision-making separate from the HMI and communication processors. This separation is critical for ensuring deterministic response times. Protective elements use sampled data from CT/VT channels processed through high-precision ADC converters. Directional elements employ digital signal processing techniques to evaluate voltage-current phase relationships, especially vital in networks with variable fault-current paths.

Communication and system integration are handled by an independent communication subsystem supporting simultaneous SCADA and station-bus messaging. With IEC 61850 capabilities, the relay supports GOOSE messaging for high-speed peer-to-peer interlocking, significantly reducing wiring and improving response times.

The engineering value of this design is clear: fast and predictable protective operation, reliable breaker management, and deep integration into modern digital substations. For retrofit scenarios, the flexibility of the F650 platform allows direct replacement of legacy GE relays while maintaining compatibility with existing control wiring and field instrumentation.