GE L90G00HCHF8FH6PLXXNXXSXXUXXW7A Line Differential Relay Unit

Module Feature

L90G00HCHF8FH6PLXXNXXSXXUXXW7A belongs to GE Multilin L90 series. It is a high-performance line differential protection relay designed for medium and high voltage power transmission lines. This GE relay uses current differential principle as main protection, equipped with comprehensive backup protection functions including overcurrent, earth fault, negative sequence overcurrent, overvoltage and undervoltage. It supports breaker control, power metering, sequence of event logging and fault oscillography. Multiple digital inputs and relay outputs are available for status acquisition and trip/alarm control. Supports Ethernet and serial communication channels for data exchange with SCADA, HMI and adjacent L90 relays for differential comparison. Panel cutout mounting structure, heavy-duty metal front panel, strong anti-electromagnetic interference capability. Widely applied in power plant substation, industrial high voltage switchgear for critical transmission line protection.

Working principle

The GE L90 relay samples current signals from CT at both ends of transmission line. Two L90 relays exchange current data via communication link. The internal CPU calculates current differential value. When internal line short circuit or earth fault occurs, differential value exceeds setting threshold, relay triggers trip output to open circuit breaker and isolate faulty line. For external faults, restraint function prevents false tripping. It continuously monitors electrical parameters, records fault waveform and time stamp, uploads real-time data to upper monitoring system.

Onboard components

Main control CPU, analog sampling circuit, flash memory chip, fault waveform storage chip, Ethernet communication module, serial communication chip, relay output group, status LED array, power management circuit.

LED indicators

Power LED, run LED, trip LED, alarm LED, communication status LED.

Hardware self-diagnosis

Power supply abnormality, analog sampling failure, memory fault, communication link error, internal hardware abnormality detection, records fault codes and event oscillography files.

Programming software

GE EnerVista configuration software for relay protection setting, communication parameter configuration, fault waveform analysis, parameter backup and firmware upgrade.

Electrical & Process Parameters

Model:L90G00HCHF8FH6PLXXNXXSXXUXXW7A Brand:GE Multilin Device type:Transmission Line Differential Protection Relay Power supply:85~264VAC / 88~300VDC Input:CT / VT analog signal Output:Dry contact trip & alarm relay Communication:Ethernet, RS485 Protection:Line differential, overcurrent, earth fault, overvoltage, undervoltage protection

Mechanical & Structure

Mounting:Panel cutout mount on high voltage switchgear door Protection class:IP65 (front panel) Housing:Aluminum front frame and plastic rear enclosure

Environmental

Operating temperature:-40℃ ~ +85℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non-condensing Certification:CE,UL compliant Status: GE original Multilin L90 series line differential protection relay for power transmission system

Installation

Follow lockout-tagout safety procedure before operation. Cut off control power and isolate CT/VT circuits. Embed GE L90 relay into cabinet panel cutout and fasten mounting clips. Wire CT, VT, control power, trip signal and communication cables. Configure line differential communication parameters, test protection action and interlock function before power-on commissioning.

Interface

Control power terminals, CT/VT analog input terminals, trip/alarm relay terminals, Ethernet port, serial communication port.

Diagnostic

Relay no power: control power missing or internal power circuit damage. Differential protection alarm: communication link failure or CT wiring polarity error. False tripping: CT saturation or parameter setting mistake.

Product Brief

GE L90G00HCHF8FH6PLXXNXXSXXUXXW7A Multilin L90 series transmission line differential protection relay, panel mount, main differential protection plus multi backup protection, used for medium/high voltage transmission line protection in substation.