Product Overview

The GE Multilin 750-P5-G5-S5-HI-A1-R-E-H​ is a microprocessor-based feeder management relay from the GE Multilin 750/760 Feeder Protection System family, designed for the primary protection, control and monitoring of medium-voltage distribution feeders. Where a simple overcurrent relay sees one quantity, the GE 750-P5-G5-S5-HI-A1-R-E-H​ supervises phase, neutral, ground and sensitive ground current simultaneously, applies directional supervision to each, and layers on voltage, frequency, reverse power, synchrocheck and breaker-management functions — all inside one draw-out case.The order code defines this specific build precisely. P5, G5 and S5 set 5 A phase, 5 A zero-sequence and 5 A sensitive ground current inputs, so the relay can detect the low-magnitude earth faults that conventional ground elements miss on high-impedance and resonant-grounded systems. HI selects the wide-range control power supply accepting 88–300 V DC or 70–265 V AC at 48–62 Hz, covering both station battery and AC supplies. A1 provides eight 0–1 mA analog outputs, R specifies the red breaker-closed LED, E adds the enhanced display with the 10BaseT Ethernet option, and H applies the harsh-environment conformal coating.Beyond protection, the GE Multilin 750-P5-G5-S5-HI-A1-R-E-H​ is a full feeder management platform: it meters current, voltage, sequence components, power and energy, records up to 256 time-stamped events, captures oscillography across four currents, three voltages and all digital states, runs a data logger, locates faults, and tracks breaker arcing current and contact wear. Because GE has discontinued 750/760 manufacturing and points to the 850 as the successor, the GE 750-P5-G5-S5-HI-A1-R-E-H​ has become a critical sustainment spare for the very large installed base still in service.

Technical Specifications

Main Features and Advantages

Three current inputs instead of two: The defining hardware advantage of the GE Multilin 750-P5-G5-S5-HI-A1-R-E-H​ is the dedicated sensitive ground channel. Standard ground overcurrent elements struggle to see high-impedance earth faults; the S5 input resolves pickup from 0.005 × CT, so a relay on a resistance-grounded or Petersen-coil system can detect fault currents that would otherwise persist undetected until they escalate. On industrial networks where a sustained earth fault means arc-flash exposure and escalating damage, that sensitivity is the difference between an alarm and a catastrophic failure.Full directional supervision: Every current element in the GE 750-P5-G5-S5-HI-A1-R-E-H​ — phase, neutral, ground, sensitive ground and negative sequence — can be made directional, polarised by voltage, current or both, with a relay characteristic angle adjustable from 0 to 359 degrees and ±2° angle accuracy. That allows genuinely selective schemes on networked and looped distribution systems, where non-directional protection would trip healthy feeders alongside the faulted one.Feeder management, not just tripping: The relay closes the loop between protection and operations. It meters what the feeder is doing, locates faults by calculating type, distance and impedance and stores the last ten, monitors breaker health through per-phase contact wear and total arcing current accumulation, supervises trip and close coils for continuity, and detects VT failure before it causes a misoperation. Four independent setting groups let one relay cover normal, maintenance and contingency configurations without re-entering settings.Records that end the argument: Up to 256 events time-stamped to 1 ms — synchronised to IRIG-B with ±1.0 ms accuracy — plus oscillography capturing four currents, three voltages, fourteen logic inputs and eight output relays, and an eight-channel data logger. Integrated COMTRADE and sequence-of-events viewers in EnerVista turn those records into a readable post-fault narrative instead of a forensic exercise.Communications without converters: Serial Modbus RTU and DNP 3.0 are standard on the GE Multilin 750-P5-G5-S5-HI-A1-R-E-H, and the E option in this build adds the 10BaseT Ethernet port carrying Modbus RTU over TCP/IP. A feeder relay can therefore talk to a legacy serial SCADA master and a modern Ethernet network at the same time.Built for the site, serviceable in place: The H option applies conformal coating for conductive dust, moisture, salt spray and chemical corrosion, and the draw-out case with CT shorting lets the GE 750-P5-G5-S5-HI-A1-R-E-H​ be withdrawn and replaced in a live panel without disturbing the wiring.