GE SR745-W2-P1-G1-HI-E Transformer Management Relay

Product Description

SR745-W2-P1-G1-HI-E is GE Multilin SR745 series legacy transformer management protection relay, designed for two-winding and three-winding power transformers. The ordering code defines W2 dual-winding configuration, P1 universal wide auxiliary power supply, G1 digital I/O set, HI high-impedance CT input to minimize CT burden, E with Ethernet communication port. It adopts multi-processor architecture, equipped with percentage differential protection with harmonic restraint to avoid misoperation during transformer magnetizing inrush. Supports RTD temperature inputs for winding and oil temperature monitoring, on-load tap changer LTC control and breaker management. Front panel with LCD display and keypad, draw-out modular construction for convenient maintenance. This SR745 series has been discontinued by GE Vernova, available spare parts are surplus new or refurbished units, replaced by GE 845 transformer relay.

Key Functions

• 87T percentage differential protection with dual slope and 2nd/5th harmonic inrush restraint
• Complete backup protection: phase overcurrent, earth fault, negative sequence, overexcitation protection
• RTD analog input for transformer winding and oil temperature monitoring
• LTC tap changer monitoring and control, breaker status monitoring and control logic
• FlexLogic programmable logic for custom interlock, alarm and control scheme
• Oscillography waveform capture, event records, fault report and power metering
• Communication: Ethernet, RS485, supports Modbus TCP/RTU, DNP3.0, IRIG-B time sync
• Self-diagnosis, watchdog fault monitoring and audit trail for setting modification record

Application Scenarios

• Utility substation two-winding / three-winding power transformer main & backup protection
• Oil & gas, chemical, mining industrial plant large distribution transformers
• Power plant auxiliary transformer monitoring and protection cabinets
• Wind farm and solar station step-up transformer protection retrofit project
• Replacement of old 745 series relays in existing substation control system

FAQ

Q1: What does HI stand for in the model?
A1: HI means high impedance current input, reduces CT load burden, suitable for long CT wiring cables.

Q2: Is SR745 still in production?
A2: SR745 series is discontinued, the new replacement model is GE Multilin 845 transformer relay.

Q3: What software is used for configuration?
A3: GE EnerVista 745 Setup software for parameter setting, testing and fault analysis.

Q4: Common faults?
A4: Ethernet communication dropout, RTD temperature reading drift, I/O contact failure, setting loss, LCD screen aging.