Overview

Transmission and distribution systems are essential for the safe, sure routing of power from generation sources to consumers. However, exposed overhead lines transporting power are by nature sometimes vulnerable and prone to fault. In the case of a faulty circuit, the MiCOM range provides speedy protection to trip and isolate it, thereby preventing further damage.

Each relay model contains multiple main protection elements: distance, delta directional incremental protection and directional earth/ground fault unit protection (DEF). This permits simplified application and spares holdings, because the relay can be adopted as the standard protection platform. 

The MiCOMho P44 is suitable for feeders controlled by a single circuit breaker and for complex installations where feeders are controlled by two circuit breakers such as ring bus/mesh corner formations and the breaker-and-a-half configurations. 

Key Benefits

• Sub-cycle fault clearance from 0.7 to 1 cycle
• Simple set mode: The relay determines its own settings from protected line data
• Power swing blocking without the need for setting
• Integral teleprotection via a MODEM, fiber or MUX channel
• Fast CB failure resetting (< 3/4 cycle)
• Phase-preference tripping for cross-country earth faults in Petersen/isolated systems
• Multi-shot 1/3pole & 3pole autoreclosure with check synchronism - adaptive technology to detect fault arc extinction and accelerate the dead time or drive to lockout for persistent faults.  Improves system stability whilst reducing OPEX.

Main Characteristics:

• Comprehensive communication options including IEC 61850 Edition 2
• IEC 61850 redundant Ethernet protocols - RSTP, PRP or HSR
• IEC 61850 9-2LE redundant PRP Process bus protocol
• Fast subcycle distance protection with quadrilateral or mho zones and setting free power swing detection
• InterMiCOM64 for transmitting digital signals (32) through teleprotection communication links
• Advanced Cybersecurity including AAA, Radius, RBAC, and Syslog

ANSI ® Device Numbers and Functions

P44 MiCOMho Line Distance Protection   Buy Now

MiCOM S1 Agile

Key benefits:

• Powerful, free of charge, PC toolsuite
• Optimum management of the installed base, structured as per the substation topology
• Intuitive and versatile interface with file management facilities
• Logical structure based on substation, voltage level and bay
• Version control and cross-checking facilities for IED settings
• Real-time measurement visualization – MiCOM S1 Agile extends to all MiCOM Agile IEDs - including P847 PMU and busbar schemes

Engineering Tool Suite

S1 Agile is the truly universal PC tool for MiCOM Agile relay, assemble all tools in a palette for simple entry, with intuitive navigation via fewer mouse-clicks. No-longer are separate tools required for redundant Ethernet configuration, phasor measurement unit commissioning, busbar scheme operational dashboards, programmable curve profiles or automatic disturbance record extraction – applications are embedded. MiCOM S1 Agile supports all existing MiCOM, K-Series and Modulex, including a utility for automatic conversion of setting files from previous generations of numerical relays like K-series and MiCOM P20 to the latest P40 Agile models.

To move to the future, with no loss of functionality, no loss of device support, and full compatibility with your installed base and system architecture – request a copy of S1 Agile with the contact form link below.

GE Vernova’s latest P44 MiCOMho 5th Generation transmission models offer a perfect functional match to our “mho” family of distance relays, from the heritage installed-base brands GEC Measurements, GEC Alsthom, GE VERNOVA and Areva. The subcycle pedigree is maintained, optimised and advanced:

SHNB Micromho and SHPM Quadramho Replacement:

• Full functional compatibility

LFZP Optimho and LFZR Replacement:

• Form, fit and functional compatibility – the P44 fits in the same panel or rack space
• The same S1 Agile software supports the new MiCOM relay and the legacy LFZR

LFDC Delta Directional Comparison Relay Replacement:

• Form, fit and functional compatibility – the P44 fits in the same panel or rack space
• Implements “delta” (incremental quantity) protection schemes along with distance zones
• Half-cycle protection response possible

MiCOMho P441/2/3/4/5/6 Relay Replacement:

• Form, fit and functional compatibility – the P44 fits in the same panel or rack space and offers the same features and Protection performance.
• The same S1 Agile software supports the new MiCOM relay and the legacy P443/5/6 and P441/2/3/4/5/6.

Pin-Pin Upgrade Methodology:

• Take the order code (CORTEC) of the older relay being removed, typically a blue case relay
• Translate to today\’s latest GE Vernova MiCOM model, adding Ethernet options if required
• Order the new P40 relay
• Extract settings and logic, use S1 Agile toolsuite to convert settings
• Detach the medium duty terminal blocks from old relay, leaving wiring attached / detach terminal blocks from the new.
• Carefully examine the terminal blocks to see that no physical damage has occurred since installation.
• Mount new relay. Old relay blocks fit straight onto the new relay - safer, less wiring to reconnect.
• It is recommended to apply rated current and voltage to the relay CT/VT inputs during secondary injection testing to check the continuity of the CT/VT terminal block connections to the relay.
• Download converted files
• Test, return circuit to service with only minutes of downtime

The MiCOM Agile P543, P544, P545 & P546 range of transmission-class protection relays provide high speed current differential unit protection. They are designed for overhead line and cable applications, interfacing readily with the longitudinal (end-end) communications channel between line terminals. The interface options support direct fiber optic or multiplexed digital links.

Each of the models offer resident subcycle distance protection to complement the powerful suite of main and backup protection. Full scheme, five-zone distance protection is adopted from the class-leading MiCOMho MiCOM Agile P443. The product line becomes the standard in all HV, EHV and UHV line protection applications, duplicated where dual redundant main protection is demanded. Set any combination of differential, distance, overcurrent and reclosing, depending on the site needs. One universal relay type instead of two or more discrete models means reduced spares holding, less training, and lower cost. 

The MiCOM Agile P544 and P546 are suitable for the complex installation and feeders controlled by two circuit breakers such as breaker-and-a-half configurations with dual breaker autoreclose logic schemes with synchrocheck for both breakers.

Key benefits:

• A universal relay that reduces spare holding - apply as a current differential relay, a distance relay, or both
• Neutral differential boosts sensitivity of tripping for resistive earth faults, even for lines with heavy load-flow 
• Transient biasing reduces CT knee point dimensioning by typically 25% compared to historical applications 
• Differential protection adaptable to all different substation topologies: in-zone transformers and unequal line end CT ratios 

Main characteristics:

• Comprehensive communication options including IEC 61850 Edition 1 and Edition 2
• IEC 61850 redundant Ethernet, supporting self healing ring, RSTP, dual homing, PRP or HSR
• Fast subcycle distance protection with quadrilateral or mho zones and setting free power swing detection
• InterMiCOM64 for transmitting digital signals through teleprotection communication links

P543 Line-Differential with Optional Subcycle Distance IED, in 60TE case 
Buy Now

Manufacturing for P544 has been discontinued. As an alternative, please refer to P54.

P545 Line-Differential with Optional Subcycle Distance IED, in 80TE case 
Buy Now

P546 Line-Differential with Optional Subcycle Distance IED, in 80TE case, suitable for two circuit breakers such as breaker-and-a-half 
Buy Now

The P546 is under last-time buy. Orders may be placed until 15^th June 2026 and will be fulfilled based upon availability. As an alternative, please refer to P54

Key benefits:

• Powerful, free of charge, PC toolsuite
• Optimum management of the installed base, structured as per the substation topology
• Intuitive and versatile interface with file management facilities
• Logical structure based on substation, voltage level and bay
• Version control and cross-checking facilities for IED settings
• Real-time measurement visualization – MiCOM S1 Agile extends to all MiCOM Agile IEDs - including P847 PMU and busbar schemes

Engineering Tool Suite

S1 Agile is the truly universal PC tool for MiCOM Agile relay, assemble all tools in a palette for simple entry, with intuitive navigation via fewer mouse-clicks. No-longer are separate tools required for redundant Ethernet configuration, phasor measurement unit commissioning, busbar scheme operational dashboards, programmable curve profiles or automatic disturbance record extraction – applications are embedded. MiCOM S1 Agile supports all existing MiCOM, K-Series and Modulex, including a utility for automatic conversion of setting files from previous generations of numerical relays like K-series and MiCOM P20 to the latest P40 Agile models.

To move to the future, with no loss of functionality, no loss of device support, and full compatibility with your installed base and system architecture – request a copy of S1 Agile with the contact form link below.

GE Vernova’s latest MiCOM P540 series models offer an ideal path to refurbish an older installed base of MiCOM P540 relays. Whether those older products were initially sold as GE VERNOVA or AREVA-branded products, newer models retain pin-pin refurbishment capability. Advantageously, users can benefit from the advancements made in protection, control, communications, hardware and cybersecurity that have taken place in the intervening years. The new P40 retains form, fit and function compatibility but delivers the latest platform and software ready for today\’s environment, and for future-proofed application for the decades ahead.

Pin-Pin Upgrade Methodology:

• Take the order code (CORTEC) of the older relay being removed, typically a blue case relay
• Translate to today’s latest GE Vernova MiCOM model, adding Ethernet options if required
• Order the new P40 relay
• Extract settings and logic, use S1 Agile toolsuite to convert settings
• Detach the terminal blocks from old relay, leaving wiring attached / detach terminal blocks from the new.
• Carefully examine the terminal blocks to see that no physical damage has occurred since installation
• Mount new relay. Old relay blocks fit straight onto the new relay - safer, less wiring to reconnect.
• It is recommended to apply rated current and voltage to the relay CT/VT inputs during secondary injection testing to check the continuity of the CT/VT terminal block connections to the relay.
• Download converted files
• Test, return circuit to service with only minutes of downtime

LFCB and MITZ Replacement:

• GE Vernova’s P545/P546 relays and P590 interfaces fit directly into the space vacated by our legacy relays, offering a perfect functional match
• Please contact us for assistance

Protection & Control

The T35 transformer protection system is a three-phase transformer relay designed to protect power transformers with up to six windings/restraints. The T35 provides for automatic or user-definable magnitude reference winding selection for CT ratio matching. The T35 performs automatic phase shift compensation for all types of transformer winding connections. The T35 algorithm allows the user to enable removal of the zero-sequence current even for delta-connected transformer windings, facilitating transformers with a variety of grounding configurations. As part of the Universal Relay (UR) Family, the T35 provides a cost-effective solution and superior protection and control.

Functional Block Diagram

ANSI Device Numbers & Functions

Key Features

• Metering - current, voltage, power, energy, frequency, temperature
• Oscillography – analog and digital parameters at 64 samples/cycle
• Event Recorder - 1024 time tagged events with 0.5ms scan of digital inputs
• Data Logger - 16 channels with sampling rate up to 1 sample/cycle
• Setting for security audit trails for tracking changes to T35 configurations

Monitoring & Diagnostic

The T35 includes high accuracy metering and recording for all AC signals. Voltage, current, and power metering are built into the relay as a standard feature. Current and voltage parameters are available as total RMS magnitude, and as fundamental frequency magnitude and angle.

Advanced Automation

The T35 incorporates advanced automation features including powerful FlexLogic™ programmable logic, communication, and SCADA capabilities that far surpass what is found in the average transformer relay. The T35 integrates seamlessly with other UR relays for complete system protection.

Key Features

Complete IEC 61850 Process Bus solution providing resource optimization and minimizing total P & C life cycle costs

• Three independent 100Mbps Ethernet ports enable purpose specific LAN support that eliminates latency effect of heavy traffic protocols on mission critical communication services
• Embedded IEEE 1588 time-synch protocol support eliminates dedicated IRIG-B wiring requirements for IEDs
• Direct I/O secures high-speed exchange of binary data between URs
• Increase network availability by reducing failover time to zero through IEC62439-3 PRP, HSR or dual HSR support

Advanced Communications

The T35 provides advanced communications technologies for remote data and engineering access, making it easy and flexible to use and integrate into new and existing infrastructures. Direct support for fiber optic Ethernet provides high-bandwidth communications allowing for low-latency controls and high-speed file transfers of relay fault and event record information. The available three independent and redundant Ethernet options provide the means to create fault tolerant communication architectures in an easy, cost-effective manner. 
The T35 supports the most popular industry standard protocols enabling easy, direct integration into DCS and SCADA systems.

Interoperability with Embedded IEC 61850

Use the T35 with integrated IEC 61850 to lower costs associated with power transformer protection, control and automation. GE Vernova’s leadership in IEC 61850 comes from thousands of installed devices and follows on years of development experience with UCA 2.0.

The T35’s IEC 61850 Process Bus module is designed to interface with the Multilin HardFiber System, allowing bi-directional IEC 61850 fiber optic communications. The HardFiber System is designed to integrate seamlessly with existing Universal Relay applications, including protection functions, FlexLogic, metering and communications. Learn more

The T35 can also connect to GE Vernova MU320 or third-party merging units using standard IEC 61869 or IEC 61850-9-2LE communication protocols.

Cyber Security - CyberSentry™ UR (FW v7.4xx)

CyberSentry enables UR devices to deliver full cyber security features that help customers to comply with NERC CIP and NITIR 7628 cyber security requirements through supporting the following core features:

Secure FW upgrade

UR FW files v7.9 and up now include a hash code that allows for authentication prior to being used for upgrading UR devices.

Password Complexity

Supporting up to 20 alpha- numeric or special characters, UR passwords exceed NERC CIP requirements for password complexity. Individual passwords per role are available.

AAA Server Support (Radius)

Enables integration with centrally managed authentication and accounting of all user activities and uses modern industry best practices and standards that meet and exceed NERC CIP requirements for authentication and password management.

Role Based Access Control (RBAC)

Efficiently administrate users and roles within UR devices. The new and advanced access functions allow users to configure up to five roles for up to eight configurable users with independent passwords. The standard “Remote Authentication Dial In User Service” (Radius) is used for authentication. 

Event Recorder (Syslog for SEM)

Capture all cyber security related events within a SOE element (login, logout, invalid password attempts, remote/local access, user in session, settings change, FW update, etc), and then serve and classify data by security level using standard Syslog data format. This enables UR devices integration with established SEM (Security Event Management) systems.

EnerVista™ Software

The EnerVista™ suite is an industry-leading set of software programs that simplifies every aspect of using the T35 relay. The EnerVista™ suite provides all the tools to monitor the status of the protected asset, maintain the relay, and integrate information measured by the T35 into DCS or SCADA monitoring systems. Convenient COMTRADE and Sequence of Events viewers are an integral part of the UR setup software included with every UR relay, to carry out postmortem event analysis and ensure proper protection system operation. Learn More

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

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

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 Vernova’s ViewPoint Monitoring software, operators are able to obtain Event logging reports of key activities such as configuration changes. These preformatted reports can be used to help ensure device and protection system integrity and perform forensic auditing of activities and changes for compliance.

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

Hardware

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 non-drawout 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.

The 345 protection relay chassis used with a draw out relay is available separately, for use as a partial replacement or in test environments. The draw out relay with no chassis is also available to order as a spare unit.

Drawout & Non-Drawout Construction

Removable terminals ease wiring and in-system testing or troubleshooting.

User Interface

The 845 has been designed for the protection, control and management of 2- and 3-winding power and distribution transformers in both utility and industrial applications. The 845 delivers comprehensive transformer health monitoring, diagnostics, and reporting with integrated connectivity to single and multi-gas transformer DGA solutions such as, GE Vernova’s Kelman Transformer Monitoring devices, delivering actionable analytics for asset optimization and life extension.

Applications:

• Primary and back-up protection and management of small, medium and larger power and distribution transformers, autotransformers and reactors
• Designed for Utility (Transmission & Distribution) or Industrial applications
• Integrated transformer protection, monitoring diagnostics and transformer health visualization

Multilin 845 feeder protection relay functional block diagram

The Multilin 8 Series supports an integrated arc flash module providing constant monitoring of an arc flash condition within the switchgear, motor control control centers, or panelboards. With a 2ms protection pass, the 8 Series is able to detect light and overcurrent using 4 arc sensors connected to the 8 Series relay. In situations where an arc flash/fault does occur, the relay is able to quickly identify the fault and issue a trip command to the associated breaker thereby reducing the total incident energy and minimizing resulting equipment damage.

Self-monitoring and diagnostics of the sensors ensures the health of the sensors as well as the full length fiber cables. LEDs on the front panel display of the 845 can be configured to indicate the health of the sensors and its connections to the relay.

Trip and Close Circuit Monitoring

The 845 relay provides Trip and Close Circuit 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.

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.

The 845 provides advanced communications technologies for remote data and engineering access, making it easy and flexible to use and integrate into new and existing infrastructures. Direct support for copper/fiber optic Ethernet provides high-bandwidth communications, allowing for low-latency controls and high-speed file transfers of relay fault and event record information. The 845 also supports two independent IP addresses, providing high flexibility for the most challenging of communication networks. Two independent network ports enables the 845 to connect with the primary protection network and the secondary monitoring network to deliver integrated asset monitoring and diagnostics by combining protection and DGA data.

The EnerVista™ suite is an industry-leading set of software programs that simplifies every aspect of using the Multilin 845.

EnerVista provides all the tools to monitor the status of the protected asset, maintain the device and integrate the information measured by the Multilin 8 Series, into SCADA or DCS process control systems. The ability to easily view sequence of events is an integral part of the setup software, as postmortem event analysis is critical to proper system management.

EnerVista Launchpad

The setup tools within Launchpad allow for the configuration of devices in real-time, by communicating via serial, Ethernet or modem connections, or offline by creating device setting files to be sent to devices at a later time.

8 Series Setup Software

8 Series Setup Software is single setup and configuration tool across the platform and can reduce device setup and configuration time.

Simplified Setup & On-Going Maintenance

ANSI ® Device Numbers and Functions

Key benefits:

• Powerful, free of charge, PC toolsuite
• Optimum management of the installed base, structured as per the substation topology
• Intuitive and versatile interface with file management facilities
• Logical structure based on substation, voltage level and bay
• Version control and cross-checking facilities for IED settings
• Real-time measurement visualization – MiCOM S1 Agile extends to all MiCOM Agile IEDs - including P847 PMU and busbar schemes

Engineering Tool Suite

S1 Agile is the truly universal PC tool for MiCOM Agile relay, assemble all tools in a palette for simple entry, with intuitive navigation via fewer mouse-clicks. No-longer are separate tools required for redundant Ethernet configuration, phasor measurement unit commissioning, busbar scheme operational dashboards, programmable curve profiles or automatic disturbance record extraction – applications are embedded. MiCOM S1 Agile supports all existing MiCOM, K-Series and Modulex, including a utility for automatic conversion of setting files from previous generations of numerical relays like K-series and MiCOM P20 to the latest P40 Agile models.

To move to the future, with no loss of functionality, no loss of device support, and full compatibility with your installed base and system architecture – request a copy of S1 Agile with the contact form link below.

GE Vernova’s latest P64 MiCOM 5th Generation models offer a perfect functional match for our MBCH and KBCH family of transformer differential relays, from the heritage installed-base brands GEC Measurements, GEC Alsthom, GE VERNOVA and Areva:

Advantages:

• Same 4U rack mounting format
• KBCH, P642/P643/P645 share the same S1 Agile PC toolsuite
• Contact us for advice and support