Protection & Control
Feeder Protection

Home > Automation & Protection > Protection & Control > Feeder Protection > 850

Protection & Control Online Store
Protection & Control Support
Protection & Control Press Room
Multilin 850
Innovative Feeder, Bay controller/ One Box Solution for Industrial and Utility Applications

The Multilin™ 850 relay is a member of the Multilin 8 Series protective relay platform and has been designed for the management, protection and control of feeder applications. The Multilin 850 is an integrated, one box solution, used to provide comprehensive protection, control and monitoring of underground and overhead feeders in industrial and utility power networks.

With 12 switchgear control elements, large color graphical display supporting configurable Single Line Diagrams, integrated annunciator panel, and 20 user configurable virtual pushbuttons, the 850 is an ideal choice for Bay Control applications.

Designed with advanced communications options and detailed asset monitoring capabilities, the Multilin 850 provides advanced functionality, including high-performance protection, extensive programmable logic and flexible configuration capabilities. With support for industry leading communications protocols and technologies, the 850 provides easy integration into new or existing SCADA or DCS for enhanced situational awareness.

To simplify the migration and upgrade from an existing SR 750/760 or 735 protection relays, retrofit kits have been developed which significantly simplify the upgrade process. Learn more

What's New
850 Overview
Arc Flash
Monitoring & Diagnostics
Communications & Cyber Security
Retrofit Kit

Full Color Graphical HMI Front Display

A large, full color Graphic Control Panel (GCP) ensures clear representation of critical status and measurements. The 8 Series offers two options for front panels:

  • 10 Programmable Push buttons with 12 programmable LEDs
  • 3 Programmable Push buttons and 12 programmable LEDs

Switchgear Control and Configurable SLD

The Multilin 8 Series provides a configurable dynamic SLD up to six (6) pages for comprehensive switchgear control of up to 3 breakers and 9 disconnect switches; including interlocks. Up to 15 digital and metering status elements can be configured per SLD page.

Platform Overview

The Multilin 8 Series platform delivers the highest level of quality, reliability and performance with…

Innovative Technology & Design

  • Patented environmental monitoring and diagnostics helps visibility on change in environmental parameters
  • Advanced, flexible and embedded communications: IEC® 61850 Ed2, IEC 62439/PRP, Modbus® RTU & TCP/IP, DNP3.0, IEC 60870-5-104, IEC 60870-5-103
  • Single setup and configuration across the platform
  • Field swappable power supply
  • Draw-out design simplifies testing, commissioning and maintenance, thereby increasing process uptime
  • Optional Wi-Fi connectivity minimizes system configuration and provides safe relay programming and diagnostic retrieval
  • Elimination of electrolytic capacitors

Exceptional Quality & Reliability

  • IPC A-610-E Class 3 Manufacturing standards – highest industry standards for electronic manufacturing
  • Highest reliability standards for electronics testing
  • 100% Environmental Stress Screening and full functional testing
  • Rated for IP54 applications
  • Standard Harsh Conformal Coating

Uncompromising Service & Support

  • Covered under GE’s 10 year warranty plan
  • Fully designed, tested and assembled at GE facilities
8 series

Multilin 850 Overview

The 850 is an advanced feeder protection relay that provides high performance protection, high density I/O, extensive programmable logic and flexible configuration capabilities. With protection and control logic, the 850 allows for simplified coordination with upstream and downstream disconnect devices.

Comprehensive feeder protection

  • Advanced breaker diagnostics with high-end fault and disturbance recording
  • High-end cyber security such as AAA, Radius, RBAC, and Syslog helps enable NERC® CIP requirements
  • Draw-out design simplifies testing, commissioning and maintenance, thereby increasing process uptime
  • Wi-Fi connectivity minimizes system configuration and provides safe relay programming and diagnostic retrieval
  • Relay environmental diagnostic information helps reduce system downtime

Multilin 850 feeder protection relay functional block diagram

850 Block Diagram

ANSI Device Numbers & Functions

Device Number Function
21 YN YN Neutral Admittance
25 Synchrocheck
27P Phase Undervoltage
27Q UV Reactive Power
27T Timed Undervoltage Protection
27X Auxiliary Undervoltage
32 Directional Power
32N Wattmetric Ground Fault (Wattmetric zero sequence directional)
37 Undercurrent
49 Thermal Overload
50BF Breaker Failure
50G Ground Instantaneous Overcurrent
50SG Sensitive Ground Instantaneous Overcurrent
50N Neutral Instantaneous Overcurrent
Device Number Function
50P Phase Instantaneous Overcurrent
50_2 Negative Sequence Instantaneous Overcurrent
51G Ground Time Overcurrent
51SG Sensitive Ground Time Overcurrent
51N Neutral Time Overcurrent
51P Phase Time Overcurrent
51_2 Negative Sequence Time Overcurrent
52 AC Circuit Breaker
55 Power Factor
59N Neutral Overvoltage
59P Phase Overvoltage
59X Auxiliary Overvoltage
59_2 Negative Sequence Overvoltage
67G Ground Directional Element
Device Number Function
67SG Sensitive Ground Directional Element
67N Neutral Directional Element
67P Phase Directional Element
67_2 Negative Sequence Directional Element
79 Automatic Recloser
81O Overfrequency
81U Underfrequency
81R Frequency Rate of Change
87G Restricted Ground Fault (RGF)
AFP Arc Flash Protection
CLP Cold Load Pickup
I1/12 Broken Conductor
MCB Manual Close Blocking
SOTF Switch Onto Fault
VTFF Voltage Transformer Fuse Failure

Integrated Arc Flash Protection

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 850 can be configured to indicate the health of the sensors and its connections to the relay.

Arc Flash

Fast, reliable arc flash protection with light-based arc flash sensors integrated within the Multilin 8 Series of protection & control devices. With arc flash detection in as fast as 2msec, the costs associated with equipment damage and unplanned downtime is significantly reduced.

Monitoring & Diagnostics

The Multilin 850 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.

Breaker Health Monitoring

The breaker is monitored by the relay not only for detection of breaker failure, but also for the overall “breaker health” which includes:

Data Logging

The Multilin 850 delivers comprehensive data logging providing the recording of 16 analog values selected from any analog values calculated by the relay. This data capture flexibility allows the operator to measure power factor or reactive power flow (for example), for several hours or even days, enabling detailed analysis and corrective action to be taken.

Environmental Monitoring

Environmental Monitoring

The 8 Series built-in environmental awareness feature (patent “Systems and methods for predicting maintenance of intelligent electronic devices”) collects the histograms of each operating condition from the point the device is put into service. Monitored environmental conditions include temperature, humidity and transient voltage. These parameters are now available as Flexelement to output alarms in case of limits reached due to Temperature, humidity or surges.

Trip and Close Circuit Monitoring

The 850 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.


The 8 Series 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 8 Series also supports two independent IP addresses providing high flexibility for the most challenging of communication networks.

Providing several Ethernet and serial port options and supporting the widest range of industry standard protocols, the 8 Series enables easy, direct integration into DCS and SCADA systems. The 8 Series supports the following protocols:

  • IEC 61850 (8 Clients, 4 Logical Devices, Tx & Rx expansion, Analog GOOSE), IEC 62439 / PRP
  • DNP 3.0 serial, DNP 3.0 TCP/IP, IEC 60870-5-103, IEC 60870-5-104
  • Modbus RTU, Modbus TCP/IP

The 8 Series has two interfaces as USB front port and Wi-Fi for ease of access to the relay.

  • Simplify set-up and configuration
  • Simplify diagnostic retrieval
  • Eliminate personnel in front of switchgear
  • WPA-2 security
8 series communications

Cyber Security

The 850 cyber security enables the device to deliver full cyber security data classification by security level using statures that help operators to comply with NERC CIP guidelines and regulations.

AAA Server Support (Radius/LDAP)

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

andard Syslog data format. This will enable integration with established SEM (Security Event Management) systems.

8 series cyber sercurity

Software & Configuration

The EnerVista™ suite is an industry-leading set of software programs that simplifies every aspect of using the Multilin 850.

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

850 set up

8 Series Retrofit Kit

Explore the 8 Series Retrofit Kit

Retrofit Existing SR 735 or SR 750/760 Devices to the Multilin 850 in Minutes

Traditionally, retrofitting an existing relay has been a challenging, time consuming task often requiring re-engineering, new drawings, panel modifications, re-wiring and re-testing.

The 8 Series Retrofit Kit provides a quick, 3-step solution to upgrade previously installed SR 735 or SR 750/760 Devices. With the new 8 Series Retrofit Kit users are able to install the 850 Feeder Management System without modifying existing cutouts and wiring, and without any drawing changes or re-engineering time.

Buy 735 to 850 Retrofit Kit Buy 750/760 to 850 Retrofit Kit

Easy 3-Step Process to Upgrade in as Fast as 21 Minutes

EnerVista 8 Series Setup Software provides automated setting file conversion. Once completed, a graphical report is provided to verify and call out any specific settings that may need attention.

Simply remove the terminal blocks and then remove the SR chassis from the panel. No need to disconnect any of the field wiring.

Insert the new 8 Series Retrofit chassis into the switchgear and simply plug-in the old terminal blocks - there is no need to make any cut-out modifications or push and pull cables.