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Multilin 345
Intuitive transformer protection

The Multilin™ 345 is a member of the Multilin 3 Series protective relay platform and has been designed for the protection, control and management of power transformers as primary or backup protection device. The 345 provides advanced transformer protection, control and monitoring in one economical draw-out or non draw-out design. The 345 contains a full range of self-contained protection and control elements as well as advanced communications, metering, monitoring and diagnostics.

Key Benefits
  • Secure high-speed protection with improved energization inhibiting
  • Field-proven algorithms and reliable protection to avoid unwanted trips or under-protection
  • Integrated transformer thermal monitoring for asset management maintenance optimization
  • Ground current supervised sensitive ground fault protection for detection of ground faults down to 5% of the winding
  • Ease of use and flexibility with one-step setup, universal CT inputs and assignable CT inputs
  • Flexible communications with multiple ports and protocols allowing seamless integration
  • Powerful Security and hierarchical password control for centralized management
  • Drawout design simplifies testing, commissioning and maintenance, thereby increasing process uptime
  • Application flexibility with the use of programmable logic elements
  • Switchgear diagnostics and easy troubleshooting by trip/close circuit supervision and LED and Digital Output Test Mode
  • Environmental monitoring system to monitor operating conditions and plan preventative maintenance
  • Robust design exceeding industry standards, with Automotive Grade components and advanced testing procedures such as accelerated life cycle testing
  • Draw out or non draw out options available
  • Simplified migration of legacy MII Family relays to the 3 Series platform
  • Intuitive configuration software and user-friendly logic configuration tool
  • Primary or backup protection of two winding power transformers
  • Protection of reactors and autotransformers
  • Protection for distribution transformers of various sizes and voltage levels
  • Applications requiring fast and secure communications
  • Harsh environments requiring protection against corrosion and humidity

  Key Features    
  • Dual slope with unique dual breakpoint differential protection with Unrestrained differential
  • Second harmonic inrush and fifth harmonic over-excitation inhibits
  • Thermal Overload and restricted Ground Fault (RGF/87G)
  • Comprehensive overcurrent elements
  • Breaker failure and lockout functions
  • Logic elements
  Protection & Control
  The 345 transformer protection system is designed to protect and control small to medium size power transformers. Flexible and powerful, the 345 provides advanced transformer protection, control and monitoring in one economical draw-out design. The 345 contains a full range of self-contained protection and control elements as detailed in the Functional Block Diagram and in the Features table.
345 Block Diagram
Sixteen logic elements available for applications such as manual control, interlocking and peer to peer tripping.
  Key Features
  • Comprehensive metering
  • Event Recorder: 256 events (1ms time stamping)
  • Programmable oscillography up to 32 samples per cycle and digital states and Fault Report
  • 4X20 character LCD display
  • Control panel with 12 LED indicators
  • Relay health diagnostics and Breaker monitoring
  • Security and password control
  • SNTP or IRIG-B time synchronization
  Power System Troubleshooting
  Analyze power system disturbances with transient fault recorder and event records
  Metering, Monitoring & Diagnostics

The 345 continuously measures and computes the following AC signals indicating the health of the protected transformer:

  • Phase winding currents
  • Winding ground current
  • Winding neutral current
  • Winding negative sequence current
  • Differential and restraint currents per-phase
  • Winding ground differential current
  • Percent 2nd and 5th harmonics differential currents per phase
  • Percent thermal capacity per-phase
  • Current demand

The states of all digital inputs/outputs are provided through the actual values either from the summary pages or individually. This includes:

  • States pf virtual inputs
  • States of remote inputs
  • States of relay outputs
  • States of logic elements
  Key Features
  • Front USB and rear serial, Ethernet and Fiber ports
  • Multiple Protocols: IEC 61850, MODBUS TCP/IP, MODBUS RTU, DNP 3.0, IEC60870-5-104, IEC60870-5-103
  Advanced Commnunications

The 345 utilizes the most advanced communication technologies today making it the easiest and most flexible transformer protection relay to use and integrate into new and existing infrastructures. Multiple communication ports and protocols allow control and easy access to information from the 345. The 345 supports the most popular industry standard protocols enabling easy, direct integration into electrical SCADA and HMI systems. Modbus RTU is provided as standard with a RS485 networking port.

The following optional protocols are available:

  • IEC 61850
  • IEC 61850 GOOSE
  • DNP 3.0
  • Modbus RTU
  • Modbus TCP/IP
  • IEC 60870-5-103
  • IEC 60870-5-104

These protocols make it easy to connect to a Utility or Industrial automation system, eliminating the need for external protocol converter devices.

  EnerVista™ Software

The EnerVista™ suite is an industry leading set of software programs that simplifies every aspect of using the 345 relay. The EnerVista™ suite provides all the tools to monitor the status of the protected asset, maintain the relay, and integrate the information measured into DCS or SCADA monitoring systems. Convenient COMTRADE and sequence of event viewers are an integral part of the 345 setup software and are included to ensure proper protection and system operation. Learn More

  Feeder protection settings in one easy step
3 Series setup software protection summary for viewing a summary of Protection & Control configuration

Access Control

Multilin devices and relays are designed with simple but powerful security to enable reliability and compliance for virtually any project or implementation. Password security is an optional feature of the 3 Series which can be setup using the SR3 EnerVista Setup software. The password system has been designed to facilitate a hierarchy for centralized management. This is accomplished through a Master level access password which can be used for resetting lower level access passwords and higher level privileged operations.

Auditing and Reporting

With the Security Audit Trail reporting feature, available in GE’s ViewPoint Monitoring software, operators are able to obtain Event logging reports of key activities such as configuration changes. These pre-formatted reports can be used to help ensure device and protection system integrity and perform forensic auditing of activities and changes for compliance.

Trace any setting changes with security audit trail.

  Key Features    
  • 4 line display for easy viewing of key data
  • 12/10 LED indicators for quick diagnostics
  • Programmable LED indicators for specific targets
  • Draw out or non draw out design options

Inputs and Outputs
The 345 features the following inputs and outputs for monitoring and control of typical transformer applications:

  • 10 contact Inputs with programmable thresholds
  • 2 Form A outputs for breaker trip and close with coil monitoring and 5 Form C output relays

Drawout & Non-Drawout Construction
The 345 is offered in both a drawout or a nondrawout construction. In the drawout case design the 345 simplifies installation and improves site safety as the need to open switchgear doors or rewire the device after testing is eliminated.

Application Flexibility & Ease of Wiring
Removable terminals ease wiring and in-system testing or troubleshooting.

  User Interface