GE Multilin SR750-P5-G5-S5-HI-A20-R-T | Feeder Relay Specs

GE Multilin SR750-P5-G5-S5-HI-A20-R-T | Feeder Relay Specs

  • Model: SR750-P5-G5-S5-HI-A20-R-T (750-P5-G5-S5-HI-A20-R-T)
  • Brand: GE Multilin / General Electric
  • Series: 750 / 760 Feeder Protection System
  • Core Function: Provides comprehensive management, metering, and fault protection for electrical distribution feeders.
  • Product Type: Feeder Management Relay
  • Key Specs: 5A Phase/Ground/Sensitive inputs, High-voltage AC/DC power, 8 analog outputs, Ethernet 10BaseT option
  • Condition: Factory Sealed / Fully Tested Surplus
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Category: SKU: GE SR750-P5-G5-S5-HI-A20-R-T

Description

Product Introduction (Non-Templated)

Substation operators analyzing sequential event recorder logs after an unexpected feeder lockout need absolute clarity on system health. When legacy protection hardware drifts out of calibration or experiences component fatigue, replacing it with an identical configuration prevents costly engineering overhead.

The SR750-P5-G5-S5-HI-A20-R-T delivers advanced digital protection and localized control across complex distribution networks. Deploying this exact hardware variant drops straight into existing panel cutouts and terminal blocks without forcing modifications to legacy protection schemes.

 

Key Technical Specifications

  • Phase Current Inputs (P5): 5 A phase current inputs
  • Ground Current Inputs (G5): 5 A zero sequence current inputs
  • Sensitive Ground Inputs (S5): 5 A sensitive ground current input
  • Control Power Supply (HI): 88 to 300 VDC, 70 to 265 VAC at 48 to 62 Hz
  • Analog Outputs (A20): Eight independent 4–20 mA analog outputs
  • Breaker Status LED (R): Red breaker closed LED indicator
  • Display & Comms (T): Enhanced display interface with an integrated Ethernet 10BaseT communication option
  • Operating Temperature: -20°C to +60°C (-4°F to 140°F)

SR750-P5-G5-S5-HI-A20-R-T

Application Scenarios & Pain Points

Nuisance tripping on main industrial feeders leads to catastrophic facility downtime, making fast hardware recovery essential for plant electrical teams.

  • Medium-Voltage Substations: Monitoring incoming utility feeds where coordination errors risk dropping entire plant loads.
  • Petrochemical Refineries: Protecting critical motor feeder circuits exposed to harsh, vibration-heavy environments.
  • Municipal Power Grids: Managing radial distribution lines requiring precise fault recording and waveform capture.

A heavy manufacturing facility in the Gulf Coast region faced repeated communication dropouts on an aging substation monitoring loop during high-humidity summer peaks. Swapping the failing unit with a verified surplus SR750-P5-G5-S5-HI-A20-R-T restored reliable SCADA polling and event tracking instantly.

 

Related Products

  • SR760-P5-G5-S5-HI-A20-R-T: Sister model in the 750/760 lineup; adds specialized transformer and motor bus protection logic differing from standard feeder-focused firmware.
  • 239-RTD-AN: GE Multilin motor protection relay; handles thermal overload and RTD temperature monitoring for smaller auxiliary skid motors downstream.
  • F650-P5-G5-HI-A20-R-E: Advanced Feeder Protection System; represents a modern, graphical upgrade path with expanded Ethernet networking capabilities.
  • M5CG-1-0-20-A: Multilin metering transducer; provides auxiliary analog conversion separate from the relay’s internal protection architecture.
  • SR469-P5-HI-A20: GE Multilin motor management relay; dedicated to large medium-voltage motor assets rather than general distribution feeders.

 

The Engineer’s Guide: Field Pitfalls to Avoid

  • CT Circuit Openings: Disconnecting secondary current transformer wires while the main line is energized generates lethal high-voltage spikes and ruins internal input coils. How to avoid: Always short-circuit the CT secondary blocks externally using a shorting block before touching any terminal screws on the relay backplane.
  • Firmware vs. Software Version Mismatch: Connecting older EnerVista setup software to a unit with a newer firmware revision can corrupt setting files or block parameter access. How to avoid: Download the matching device file version from the manufacturer support portal before pushing configurations to the relay (take your time verifying those software profiles—a mismatched template throws annoying configuration errors during commissioning).
  • Auxiliary Control Voltage Transients: Spikes on the wide-range HI power supply rail can lock up the microprocessor core if internal MOV surge suppressors have degraded over time. How to avoid: Inspect panel-level surge protection devices upstream of the DC substation battery feed during routine maintenance checks.

 

Frequently Asked Questions (FAQ)

  • What does the ‘T’ suffix designate in this specific catalog string? The ‘T’ indicates the inclusion of an enhanced display coupled with an onboard Ethernet 10BaseT port for direct network communication.
  • Can I hot-swap this relay without isolating the primary switchgear? No, due to hardwired CT inputs and trip control circuits, you must trip the breaker and isolate control power before sliding the unit out of its chassis.
  • What software is required to configure and pull event logs from the SR750? Configuration, oscillography extraction, and setting management are handled using GE’s EnerVista 750/760 Setup software suite.
  • Why is the relay showing a self-test error on startup? Internal hardware diagnostics check memory integrity and watchdog timers; a persistent fault usually points to corrupted non-volatile memory or a failing internal power supply board.
  • Are factory-sealed surplus units shipped with default factory settings? Yes, units typically ship with baseline default parameters, requiring you to upload your facility’s specific coordination study and protection settings prior to service.

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