Product Core Brief

• Model: 760-P1-G1-S1-LO-A20-R
• Brand: GE Multilin
• Series: SR750/SR760 Feeder Management Relay
• Core Function: Digital feeder management relay that provides primary protection, control, metering, and communication for distribution feeders, with 1 A CT inputs and low-range control power.
• Product Type: Feeder Management / Protection Relay
• Key Specs: 1 A phase/neutral/sensitive ground CT inputs | Low-range control power (LO) | Serial communications (S1) | 4–20 mA analog outputs (A20) | Draw-out case (R) | Reclosing capability (760)
• Condition: New Original / New Surplus

Key Technical Specifications

• Part Number: 760-P1-G1-S1-LO-A20-R
• Product Family: GE Multilin SR750/SR760 Feeder Management Relay
• CT Input Rating: 1 A nominal for phase, neutral, and sensitive ground current inputs
• Control Power: LO low-range supply; typically 20–60 VDC or 48–62 VAC (20–48 Hz) class
• Communications: S1 serial communications; RS232 front port and RS485/RS422 rear ports supporting Modbus RTU and DNP3
• Analog Outputs: A20 4–20 mA analog transducer outputs for SCADA/PLC metering
• Protection Functions: Time/instantaneous overcurrent, ground overcurrent, sensitive ground, directional overcurrent, voltage/frequency protection, synchrocheck, and automatic bus transfer
• 760-Specific Feature: Up to 4-shot recloser function, not available on the SR750
• HMI: 40-character alphanumeric LCD, keypad navigation, and status LEDs
• Mechanical: Draw-out cradle for replacement without disturbing field wiring
• Configuration Software: GE Multilin EnerVista 760 software
• Typical Applications: MV/LV distribution feeders, bus tie schemes, DG interconnection, arc-flash mitigation, and feeder backup protection

 

Product Introduction (No Fluff)

The GE Multilin 760-P1-G1-S1-LO-A20-R is an SR760 feeder management relay designed for primary protection, control, metering, and communication on distribution feeders. This specific order code indicates 1 A CT inputs, a low-range control power supply, serial communications, 4–20 mA analog outputs, and a draw-out case.

Unlike the SR750, the SR760 includes an integrated recloser function with up to four reclosing shots, making it suitable for feeders where automatic restoration is required. The relay supports phase, neutral, and sensitive ground protection, along with voltage, frequency, directional, and synchrocheck functions. Because CT input rating and control power range are order-code dependent, replacement units must match the original P1 and LO options to avoid CT mismatch or power supply incompatibility.

 

QA & Testing SOP (Dynamic & Transparent)

For a feeder management relay, we verify identification, physical condition, terminal integrity, and configuration readiness before release.

• Part number verification: Confirm 760-P1-G1-S1-LO-A20-R on the nameplate. Record firmware version, serial number, and date code for traceability.
• Visual inspection: Check the draw-out cradle, front HMI, terminal blocks, communication ports, and case latches for mechanical damage, corrosion, or burn marks.
• CT input verification: Confirm the relay is configured for 1 A CT inputs. Applying 5 A test currents to a P1 unit can damage CT circuits or produce incorrect measurements.
• Control power check: Verify LO control power range before energizing. Applying HI-range voltage to an LO unit may damage the power supply.
• Communication test: Verify RS232/RS485 connectivity using EnerVista 760 software. Confirm Modbus/DNP3 addressing if the relay is integrated into SCADA.
• I/O and analog output check: Test digital inputs, trip/close outputs, and 4–20 mA analog outputs against configured scaling.
• Firmware and setting review: Record firmware version and export setting files. Firmware differences can affect reclosing, synchrocheck, and auto-transfer behavior.
• ESD-safe packaging: Ship in anti-static bags with foam protection. Include part number, firmware version, and inspection status on the shipping label.

 

Installation Pitfalls & Guide (Engineer to Engineer)

❗ P1 means 1 A CT inputs. Do not connect 5 A CT secondaries to a P1 relay. This can cause measurement errors, protection misoperation, or CT circuit damage.

❗ LO control power is low-range. Verify the station DC/AC supply before energizing. Applying a HI-range supply to an LO unit can permanently damage the internal power supply.

❗ SR760 and SR750 are not fully interchangeable. The SR760 supports reclosing; the SR750 does not. Replacing one with the other may change auto-reclose, bus transfer, or protection logic behavior.

❗ Do not restore trip/close wiring without verifying I/O maps. Digital outputs and analog outputs are configurable. Incorrect mapping can cause unintended tripping or incorrect SCADA readings.

❗ Follow protection system safety procedures. Never work on live trip circuits, breaker control circuits, or CT secondaries without proper isolation, CT shorting, and permit-to-work controls.

Replacement steps:

1. Pre-install: Export existing settings via EnerVista 760, record I/O assignments, CT/VT ratios, communication addresses, and alarm history.
2. Isolate: Remove trip/close enable, isolate CT/VT circuits per protection testing procedures, and remove control power.
3. Remove: Unlock and withdraw the relay from the draw-out cradle without disturbing field wiring.
4. Install: Insert the replacement 760-P1-G1-S1-LO-A20-R, restore control power, and verify CT/VT readings.
5. Commission: Download settings, test protection elements, verify reclosing logic if enabled, test 4–20 mA outputs, and confirm SCADA communication before returning to service.

 

Technical FAQ

What does 760-P1-G1-S1-LO-A20-R mean?
P1 = 1 A CT inputs; G1 = ground protection package; S1 = serial communications; LO = low-range control power; A20 = 4–20 mA analog outputs; R = draw-out case.

Can I replace a 760-P5 unit with this P1 unit?
No. P5 indicates 5 A CT inputs, while P1 indicates 1 A CT inputs. Swapping them without changing CT secondaries or relay settings will cause measurement and protection errors.

What is the difference between SR750 and SR760?
Both are feeder management relays, but the SR760 includes a 4-shot recloser function that the SR750 does not have.

Does this relay support Ethernet?
Not on this order code. S1 indicates serial communications. Ethernet is typically an optional communication option on other 750/760 variants.

Is this relay still supported?
The SR750/SR760 platform remains widely installed and supported through spare parts and EnerVista software. For new projects, GE Vernova offers updated feeder protection platforms, but 760 units are still commonly used for replacements and retrofits.