Merging unit

Merging unit – SIPROTEC 6MU805


Merging unit SIPROTEC 6MU805 for conventional instrument transformers. 

Features & functions

Merging unit SIPROTEC 6MU805


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