General Electric Multilin L90-H03-HKH-F8L-H6D-L6C-NXX-SXX-UXX-W7I

Line Current Differential Protection System

Technical Specifications

Product Overview

The L90-H03-HKH-F8L-H6D-L6C-NXX-SXX-UXX-W7I is a sophisticated line current differential protection relay designed for overhead lines, tapped transformer feeders, and single or dual-breaker circuits requiring autoreclosing capabilities.

This system utilizes an adaptive statistical restraint approach to detect high-impedance ground faults, enhancing protection sensitivity and selectivity.

Contact Output/Input Module

• Each module contains 24 terminal connections, arranged in 8 rows by 3 terminals.

• Each row corresponds to a relay’s Form-C contacts: normally closed (NC), normally open (NO), and common (COM).

• Refer to the 1601-0081-AB2 user manual for specific contact configurations, as they vary by system model.

Error Detection & Synchronization

• Features a built-in error detection system employing a 32-bit CRC check to identify erroneous data that could cause misoperation.

• Supports GPS time synchronization to correct up to 10 ms of channel asymmetry on multiplexed communication channels.

Advanced Functionality

• Records and time-stamps operation events for troubleshooting and sequence of operations analysis.

• Provides graphical displays of ground phase distance elements for selected zones.

• Analyzes line faults at a rate of 64 samples per cycle, reducing troubleshooting time and improving system insight.

Frequently Asked Questions (FAQs)

Q1: What differentiates the L90-H03-HKH-F8L-H6D-L6C-NXX-SXX-UXX-W7I from other L90 Multilin universal relays?

• The W7I order code indicates inter-relay communications using 1300 nm multimode LED channels.

• The L6C specifies the digital I/O includes eight form-C outputs.

• The H6D indicates 19 digital inputs.

• The F8L refers to the standard 4CT/4VT DSP with enhanced diagnostics.

• The H03 designates the standard 19-inch horizontal rack with IEC 61850 software option.

Q2: How does the L90 Multilin protect against overvoltage and undervoltage conditions?

• For long lines with little or no load, voltage may rise above rated levels.

• The L90’s three-phase overvoltage protection triggers local and remote trips via Direct Transfer Tripping (DTT) to prevent equipment damage.