Merging unit SIPROTEC 6MU85

Merging unit SIPROTEC 6MU85

Product Overview

The SIPROTEC 6MU85 Merging Unit is the modular, interoperable and powerful solution between primary and secondary technology – versatile process data acquisition, autonomous automation and secure communication. It is designed for conventional and non-conventional instrument transformers (LPITs) and digitalizes all primary data close to the process.

Features :

Main functions:

  • Merging unit
  • Bay unit for distributes busbur protection SIPROTEC 7SS85
  • Breaker functions
  • Backup protection functions
  • Additional functions


  • Up to 4 sampled measured value streams according IEC 61850-9-2 LE or IEC 61869 flexible streams

Hardware flexibility:

  • Flexibly adjustable and expandable I/O quantity structure within the scope of the modular SIPROTEC 5 system; 1/6 expansion modules can be added.

Housing width:

  • 1/3 × 19 inches to 2/1 × 19 inches

As standard:

Functions :

Merging unit

  • Per ETH-BD-2FO Ethernet module 1 or 2 Sampled Measured Value (SMV) streams
  • – up to 32 analog values in any combination of CTs and VTs
    – 4x CTs, 4x VTs (IEC 61850-9-2 LE)
  • Up to 4 ETH-BD-2FO modules possible
  • Reliable and redundant data transmission via PRP protocol
  • IEC 61869-9, IEC 61869-13 compliant
  • IEC 61850-8-1 GOOSE, MMS and merging unit protocol on the same Ethernet module
  • Sample and date/time synchronization via IEEE 1588v2/PTP
  • Redundant power supply
  • Extended temperature range (-40 ºC to 70 ºC)

Breaker functions

  • Control with switchgear interlocking
  • Circuit-breaker failure protection (50BF)
  • Circuit-breaker wear monitoring
  • Switching statistics
  • Point on wave switching (PoW)
  • Trip-circuit supervision (74TC)
  • Automatic reclosing (79)
  • Synchrocheck (25)

Backup protection functions

  • Non-directional overcurrent protection (50/51, 50N/51N)
  • Directional overcurrent protection (67/67N)
  • Overvoltage and undervoltage protection (27/59)

Additional functions

  • Phasor measurement unit (PMU) for synchrophasor measured values and IEEE C37.118 protocol
  • Arc protection
  • Auxiliary functions for simple tests and commissioning
  • Temperature measurement via thermobox TR1200 (7XV5662-6AD10 or 7XV5662-8AD10)
  • 4-20 mA transducer inputs for various analog process values, e.g pressure, tap-changer position
  • PQ-Basic: voltage unbalance; voltage changes: overvoltage, dip, interruption; TDD, THD and Harmonics


  • Pluggable communication modules, usable for different and redundant protocols (IEC 61850-8-1, IEC 61850-9-2 Merging Unit, IEC 60870-5-103, IEC 60870-5-104, Modbus TCP, DNP3 serial and TCP, PROFINET IO, PROFINET IO S2 redundancy)
  • Serial protection data communication via optical fibers, two-wire connections and communication networks (IEEE C37.94, and others), including automatic switchover between ring and chain topology
  • Extensive cybersecurity functionality, such as role-based access control (RBAC), protocolling security-related events, signed firmware or authenticated network access IEEE 802.1X
  • Simple, quick and secure access to the device data via a standard Web browser to display all information and diagnostic data, as well as vector diagrams, single-line and device display pages
  • Virtual network sharing (IEEE 802.1Q – VLAN)

More Information


+66 2 063 5262-3, +66 83 440 1404