Siemens 7UT6331-4EB92-2BC3 SIPROTEC 4 Differential Protection Relay

The Siemens 7UT6331-4EB92-2BC3 is a numerical differential protection relay belonging to the SIPROTEC 4 series. It is designed as main protection for two-winding and three-winding transformers, also applicable to generators, motors, small busbars and short transmission line fault detection.

This relay integrates harmonic restraint to avoid maloperation caused by transformer inrush current, equipped with comprehensive backup protection and multiple communication interfaces. It supports parameter configuration via DIGSI 4 software and provides detailed fault recording. Widely used for power substation protection cabinet maintenance, system renovation and spare parts supply.

Main Specifications

• Brand: Siemens
• Model: 7UT6331-4EB92-2BC3 (SIPROTEC 4 7UT633)
• Product Type: Transformer Differential Protection Relay
• Core Protection: 87T Transformer Differential Protection
• Anti-Inrush: Second harmonic restraint algorithm
• Communication: IEC 61850, IEC 60870-5-103, Modbus
• Local Interface: Front service port for DIGSI 4 debugging
• Input/Output: Programmable binary inputs and relay trip outputs
• Operating Temperature: -20°C ~ +55°C
• Installation: 19-inch standard panel flush mounting

Core Functions

• Identify internal short-circuit faults of transformers and send trip command rapidly
• Second harmonic restraint prevents false tripping during transformer energization
• Built-in phase compensation for delta-wye connected transformers
• Integrated phase overcurrent, earth fault and negative-sequence backup protection
• Support restricted earth fault protection to improve ground fault sensitivity
• Capture fault waveforms and store event records for post-fault analysis
• Real-time measurement of three-phase current, voltage and power parameters
• Flexible setting groups for different operation modes of power equipment
• Continuous self-monitoring to detect hardware and wiring abnormalities
• Transmit protection status and alarm data to SCADA and substation automation system

Application Scenarios

• Power plant main transformer and auxiliary transformer protection systems
• Urban and industrial high-voltage substation transformer protection cabinets
• Oil & gas field power distribution transformer protection control panels
• Petrochemical plant medium voltage transformer safety protection projects
• Metallurgy and mining factory power supply equipment protection platforms
• Data center and large commercial complex power transformation stations
• Wind farm and photovoltaic station booster transformer protection systems
• Railway traction power substation transformer protection solutions
• SIPROTEC 4 protection system upgrading and spare parts replacement work
• Medium & high voltage power system primary equipment differential protection projects