Description

GE‑Vernova Multilin SR745‑W3‑P5‑G5‑HI‑ALR‑E‑H Transformer Management Relay

Technical Specifications

• Product Model: SR745‑W3‑P5‑G5‑HI‑ALR‑E‑H (SR745W3P5G5HALIREH)
• Brand: GE‑Vernova (GE Multilin)
• Warranty: One Year
• Input Voltage: 70‑265 V AC / 90‑300 V DC universal control power, 48‑62 Hz
• Operating Temperature: ‑40 °C ~ +60 °C
• Storage Temperature: ‑40 °C ~ +85 °C
• Response Time: Differential protection operate time ≤2 ms; fault‑event recording high‑speed sampling
• Protection Class: IP20 (panel‑mount metal housing)
• Accuracy Class: ANSI/IEEE power‑system protection grade; metering accuracy ±0.2%
• Output Frequency: 50 Hz / 60 Hz nominal system frequency
• Rated Current: CT secondary 5 A nominal (P5 code); phase, neutral & sensitive ground current inputs
• Transformer Support: Three‑winding transformer protection (W3 code)
• Display: Enhanced 40‑character backlit LCD + membrane keypad for local setpoint & metering view
• Logic Inputs: 16 programmable opto‑isolated digital logic inputs
• Output Relays: Multiple trip / alarm contact outputs (G5 relay configuration)
• Communication: Ethernet, RS232, RS485; Protocols: Modbus‑TCP, Modbus‑RTU, DNP3, IEC‑61850; IRIG‑B time‑sync input
• Core Protection Functions: 87T transformer percentage differential (2nd/5th harmonic restraint), 64REF restricted earth fault, phase‑ground overcurrent, over‑excitation, over‑voltage / under‑voltage, thermal overload protection
• Software Tool: EnerVista UR Setup for configuration, fault‑event analysis, disturbance record viewing
• Event / Fault Recording: 512 event logs; 64 oscillographic disturbance records
• FlexLogic: User‑configurable programmable logic for custom interlock logic
• Certifications: CE, UL/cUL, IEEE, ANSI compliance
• Humidity: 5‑90 % RH, non‑condensing
• Weight: 4.8 kg
• Dimensions: 229 × 178 × 184 mm (H × W × D)

Product Overview

The SR745‑W3‑P5‑G5‑HI‑ALR‑E‑H is a high‑performance numerical transformer management relay from GE Multilin 745 series, built for three‑winding power transformers in substations and heavy‑industry power systems. This full‑feature unit integrates primary differential protection, backup overcurrent protection, thermal monitoring, metering, sequence‑of‑events logging and breaker control inside one panel‑mount chassis.

Harmonic‑restrained differential algorithm reliably distinguishes internal winding faults from transformer magnetizing inrush conditions. Restricted earth fault protection delivers high‑sensitivity detection for winding‑to‑ground failures. Built‑in FlexLogic enables custom interlock logic without external auxiliary relays. Local LCD keypad supports on‑site parameter checking and setting modification. Multi‑protocol communication interfaces upload real‑time measurements, alarms and fault‑oscillography data to SCADA, DCS and plant asset‑management hosts. Original OEM production is mature; most available units are refurbished or new‑old‑stock spare parts for substation‑equipment overhaul and maintenance projects.

Application Notes

‑ Designed for panel cut‑out mounting inside control‑room cabinet; avoid direct sunlight, dust accumulation and condensation. ‑ CT secondary rating is 5 A; confirm CT ratio setting matches field instrument transformers during commissioning. ‑ Use EnerVista UR Setup software for relay configuration, firmware upgrade and fault‑disturbance file analysis. ‑ IRIG‑B time‑sync wiring is recommended for accurate sequence‑of‑event timestamp alignment across substation devices. ‑ Verify full ordering‑code feature matching when replacing existing SR745 units; suffix codes define winding quantity, relay‑output, communication and hardware‑option sets. ‑ Not hot‑swappable; isolate control power and CT secondary circuits before unit removal. ‑ Typical deployment: utility power substations, combined‑cycle power plants, refineries, heavy‑industry main‑transformer protection‑system spare‑part stocking and retrofits.