Product Core Brief
- Model: 745-W3-P5-G5-HI-A-L-R-E-H
- Brand: General Electric (GE) Multilin
- Series: 745 Transformer Protection System
- Core Function: High-speed differential, overcurrent, and management protection for 3-winding power transformers.
- Product Type: Digital Protective Relay
- Key Specs: 3-Winding Support | 5A Phase/Ground CT Inputs | High Control Power (HI) | Enhanced Options (A-L-R-E-H)
Condition: New Original (New Surplus)
Product Introduction
GE 745-W3-P5-G5-HI-A-L-R-E-H is a micro-controller-based transformer management relay engineered for high-speed differential and overcurrent protection on 3-winding power transformers. Operating within medium to extra-high voltage sub-stations, this unit tracks harmonic restraints, phase shifts, and tap changer settings to calculate internal fault conditions accurately while preventing nuisance tripping during inrush currents.
This module features integrated 5 A CT inputs, redundant communication ports, an Ethernet interface, and conformal-coated internal boards for high immunity against ambient contaminants. It simplifies sub-station automation loops by delivering comprehensive metering, event recording, and oscillography over standard industrial protocols.
Quality Control & Inspection Process
Surplus protective relays require rigorous testing to confirm trip reliability before commissioning. Every unit follows a strict 5-step quality assurance process:
- Inbound Inspection: Check customs manifests, serial numbers, and physical casing. Inspect current terminals, rear wiring blocks, and front keypad buttons for structural integrity or corrosion.
- Live Functional Testing: Mount the unit on a relay test bench powered by a high-voltage auxiliary supply. Inject simulated 3-phase current profiles using a secondary injection test set to verify IEEE 87T differential pickup thresholds, trip response times, and 24-hr continuous stability.
- Electrical Testing: Conduct insulation resistance checks with a 500 V Megger (verifying >10 MΩ to ground chassis) and verify isolation across input CT terminals.
- Firmware & Configuration: Connect via EnerVista 745 Setup software to read and document exact firmware builds. Back up default settings, clear fault records, and verify DIP/jumper states.
- Final QC & Packaging: Enclose the relay in anti-static ESD bags with desiccant packs. Frame securely in thick foam inside a heavy-duty carton stamped with a QC Passed label.
