745-w2-p5-g5-hi-r-e-h_ge_motor

Product Overview

The 745-W2-P5-G5-HI-R-E-H is a digital transformer management relay from the GE Multilin 745 series, engineered for the protection, monitoring, and control of two-winding power transformers, autotransformers, and reactors. As a full-featured protection relay within the Multilin platform, the 745-W2-P5-G5-HI-R-E-H consolidates percentage differential protection, restricted ground fault, overcurrent, overexcitation, and thermal overload functions into a single draw-out chassis, replacing discrete electromechanical devices with a unified, software-configurable solution.

Each segment of the 745-W2-P5-G5-HI-R-E-H order code defines a specific hardware and functional configuration. “W2” designates two-winding transformer protection capability; “P5” and “G5” specify 5 A phase and ground CT secondary inputs respectively; “HI” indicates a wide-range control power supply accepting 90–300 VDC or 70–265 VAC; “R” adds the restricted ground fault element; “E” denotes the enhanced 40-character LCD display with expanded keypad; and “H” represents conformal coating on the PCB assembly for protection against dust, moisture, and chemical contaminants.

Manufacturing for the 745 platform has been discontinued by GE Vernova, with the 845 relay positioned as the successor. The 745-W2-P5-G5-HI-R-E-H therefore remains a legacy sustainment item, in continued demand across power generation, transmission, and heavy industrial facilities where existing 745 installations require like-for-like replacement to maintain configuration compatibility and protection system integrity.

Technical Specifications

Parameter Name	Parameter Value
Product Model	745-W2-P5-G5-HI-R-E-H
Manufacturer	GE Multilin (GE Vernova / GE Grid Solutions)
Product Type	Transformer Management Relay / Digital Protection IED
Series	GE Multilin 745 Transformer Protection System
Winding Configuration	2-winding (W2)
Phase CT Rating	5 A secondary (P5)
Ground CT Rating	5 A secondary (G5)
Control Power	90–300 VDC / 70–265 VAC, 48–62 Hz (HI)
Restricted Ground Fault	Included (R)
Display	Enhanced 40-character LCD with expanded keypad (E)
Environmental Protection	Conformal coating on PCB (H)
Communication Protocols	Modbus RTU, DNP 3.0 Level 2
Communication Ports	Front RS232; Rear RS485/RS422
Logic Inputs	16
Mounting	Standard 19-inch panel, draw-out case
Operating Temperature	-20°C to +60°C
Dimensions	9″ H × 7″ W × 7⅛” D (approximate)
Weight	Approximately 4.8 kg

Main Features and Advantages

Comprehensive protection in a single chassis: The 745-W2-P5-G5-HI-R-E-H integrates percentage differential protection with harmonic restraint, restricted ground fault detection, phase/neutral/ground overcurrent elements, overexcitation (V/Hz) protection, frequency rate-of-change detection, and thermal overload protection. This consolidation reduces panel space, wiring complexity, and the coordination burden associated with multiple discrete relays.

Adaptive CT ratio mismatch correction: The 745-W2-P5-G5-HI-R-E-H performs digital CT ratio matching and phase vector group compensation internally through software configuration, eliminating the need for external interposing CTs. In real installations where CT ratios on the high and low sides of a transformer rarely match perfectly, this capability allows the differential element to operate with higher sensitivity without producing false differential current.

Draw-out construction with CT shorting: The 745-W2-P5-G5-HI-R-E-H is housed in a draw-out case that automatically shorts the CT circuits upon withdrawal. This design enables field replacement of the relay module without rewiring the panel, a decisive advantage for legacy sustainment where rapid restoration of protection is critical.

Environmental hardening: The “H” suffix on the 745-W2-P5-G5-HI-R-E-H indicates conformal coating applied to the PCB assembly, qualifying the relay for installation in chemically aggressive, high-humidity, or dusty environments commonly found in petrochemical plants and coastal substations.