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.

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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

• Temperature monitoring via remote RTD’s using the RMIO module supporting up to 12 RTDs

• 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

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Applications

• 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

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Protection & Control

Key Benefits:

• 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

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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. The 345 can be even used for dual feeder protection.

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Monitoring & Metering

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

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Power System Troubleshooting

Analyze power system disturbances with transient fault recorder and event records.

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

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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

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Communications

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

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Advanced Communications

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.

 

Trip and Close Circuit Monitoring

The 845 relay provides Trip and Close Circui Monitoring elements

Breaker Arcing Current

This element calculates an estimate of the per-phase wear on the breaker contacts by measuring and integrating the current squared passing through the breaker contacts as an arc. When the threshold is exceeded in any phase, the relay can set an output operand and set an alarm.

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Breaker Health

The 845 relay provides breaker health information by monitoring and analyzing the operation count, arcing energy of breaking current, arcing time, tripping time, closing time and spring charging time if applicable.

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Integrated Electrical and DGA for Comprehensive Transformer Monitoring & Diagnostics

The Multilin 845 offers advanced transformer health monitoring and diagnostics through advanced notification of potential issues before they become critical. The Multilin 845 features detailed learned data, summarized pre/post-fault records, and integration with GE’s DGA devices to collect, trend, and analyze a transformer’s fault gasses. This enables operators to minimize costly unplanned outages and equipment failures.

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