SAC PSL6254D Line Protection IED Unit

Module Feature

PSL6254D is a full-function line differential protection IED under SAC PSL6200 product family.

It adopts percentage restrained differential algorithm for phase and earth fault detection, with stable performance against magnetizing inrush, load switching and external fault saturation. It integrates fiber differential, directional overcurrent, residual overcurrent, over/under voltage, auto-reclosing, breaker failure protection and remote control. It supports IEC61850, GOOSE, IEC 60870-5-103 and Modbus communication. It is widely deployed in 110kV transmission and distribution substations, industrial power feeders and small power plant outgoing bays.

Working principle

The IED exchanges synchronized current sampling data with the opposite-end relay via dedicated optical fiber channel.

It calculates differential current to identify internal line fault and sends trip signal to open circuit breakers. It records COMTRADE fault waveforms, time-stamped event sequences and electrical measurements, and uploads real-time data and alarms to substation SCADA system.

Onboard components

Main CPU board, AC CT/VT sampling module, optical fiber communication interface, binary input/output matrix, local LCD HMI panel, auxiliary power supply circuit, status LED array.

LED indicators

Front LEDs indicate power health, running status, trip flag, fiber channel link and communication fault alarm.

Hardware self‑diagnosis

Built-in supervision detects fiber channel interruption, CT open circuit, VT fuse loss, internal hardware abnormality and over-temperature. Fault codes and event records are displayed on local panel and engineering software.

Programming softwareSAC Power System Configuration Tool, used for protection setting, channel delay calibration, auto-reclose logic configuration and fault waveform analysis.

Electrical & Process Parameters

Model:PSL6254D Brand:SAC (Guodian Nanjing Automation) Device type:Line differential protection and control IED Auxiliary supply:88–264V DC / 85–264V AC CT input:1A / 5A Function:Fiber differential, backup protection, reclosing and bay control for transmission lines

Mechanical & Structure

Mounting:Panel cutout installation Protection class:IP20 Housing:Metal relay enclosure

Environmental

Operating temperature:-25℃ ~ +55℃ Storage temperature:-40℃ ~ +85℃ Ambient humidity:5~95% non‑condensing

Certification:CE, IEC

Status:Original SAC power substation protection spare

Installation

Install IED inside protection panel, connect CT/VT wiring, auxiliary supply and paired fiber channel.

Check CT polarity, perform differential stability test and GOOSE interlock verification before energizing.

InterfaceCT/VT analog terminals, binary I/O terminals, optical fiber port, Ethernet communication port.

Diagnostic

Differential unstable: Wrong CT polarity, inconsistent sampling delay or fiber channel jitter. Channel dropout: Broken optical fiber, optical module failure or mismatched communication parameters. Reclose refusal: Breaker auxiliary contact fault or interlock blocking.

Product Brief

SAC PSL6254D protection IED, fiber differential relay for 110kV transmission line bay protection and control replacement.