Merging unit

Merging unit – SIPROTEC 6MU805


Merging unit SIPROTEC 6MU805 for conventional instrument transformers. 

Merging unit SIPROTEC 6MU805

Features & functions


This device allows conversion of current substations to process bus substations without change in the primary equipment. The advantages of process bus can be used, but also a mixed configuration of process bus / non-process bus is possible.


Siemens process bus solutions not only fulfill the standard but increase customer value beyond.


The SIPROTEC 6MU80 merging units are not only certified according IEC 61850-9-2LE for process bus applications but include a lot of additional features. Some, but not all, of the additional features are:

  • Extended temperature range (-40 ºC – 70 °C)

  • Configurable 12 binary inputs / 8 binary outputs

  • Time synchronization via PPS, IRIG-B or GPS

  • Full support IEC 61850-8-1 GOOSE

  • PRP and HSR (IEC 62439)

  • Integrated Web-Server

  • Comprehensive engineering with DIGSI

  • Full integration of whole substations in process bus technology by keeping well known engineering concepts of SIPROTEC.


  • Minimize wiring by measuring directly at the sensors, operating at a central position and use of fiber optical Ethernet

  • Enhanced safety by avoiding open wire condition at relays

  • Easier extension / maintenance, adding a device only connection to the network necessary. No direct connection to the sensors required

  • Maximum network reliability, through seamless redundancy protocols

  • Interoperability ensured, standardized in IEC 61850-9-2

  • Merging Units for conventional CT/VT offer process bus advantages without change in primary Equipment



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