Description
Product Introduction
Upgrading substation protection without matching exact ordering codes often leads to wiring mismatch and nuisance trips during energization. The 745-W3-P5-G5-HI-A-L-R-E-H GE protective relay eliminates integration delays by offering a fully configured feature set tailored for three-winding power transformers. Built on the proven GE Multilin architecture, this microprocessor-based unit provides high-speed percent differential protection, restrained ground fault algorithms, and comprehensive harmonic restraint to prevent false tripping during transformer inrush currents.
Field engineering data confirms that digital filtering inside this module keeps differential trip processing well under 16 ms. Replacing an aging management unit with this exact model code ensures direct physical terminal alignment and parameter software compatibility. In my experience, attempting to adapt a two-winding or mismatched option code unit into a live three-winding scheme causes unnecessary panel rewiring and safety risks. This unit arrives pre-inspected from surplus warehouse stock, ready to restore full primary transformer protection on your substation bus.
Key Technical Specifications
- Parameter: Value
- Full Part Number: 745-W3-P5-G5-HI-A-L-R-E-H
- Manufacturer: General Electric Multilin
- Protection Focus: Three-winding power transformer differential protection
- Winding Configuration (W3): Three 3-phase winding current inputs
- Phase Current Inputs (P5): 5 A nominal phase CT secondaries
- Ground Current Inputs (G5): 5 A nominal ground CT secondaries
- Control Power Supply (HI): High power supply range (88–300 V DC / 70–265 V AC)
- Analog Inputs/Outputs (A): 8 analog outputs, 4 analog inputs
- Display Option (L): English display with LED status faceplate
- Redundancy (R): Redundant RS485 communication ports
- Conformal Coating (E): Enhanced conformal coated circuit boards
- Harsh Environment (H): Harsh environment protection hardware enclosure
Installation & Configuration Guide
Phase 1 — Pre-Installation (est. 10 min) Isolate all potential voltage and control power sources supplying the panel slot. Short-circuit all current transformer (CT) secondary loops using terminal test switches before touching rear wiring. Gather a torque screwdriver set, digital multimeter, and a laptop loaded with EnerVista 745 Setup software. Save existing protection setting files (.745) and document rear terminal block wiring paths with photographs.
Phase 2 — Removal (est. 5 min) Verify that CT shorting blocks are securely shorted across every active phase circuit. Unfasten all terminal plug block securing screws and gently disconnect secondary wiring bundles. Undo the panel mounting collar hardware holding the drawout or panel-mount chassis. Slide the old relay out of the cutout perpendicular to the panel faceplate while supporting its weight from underneath.
