M19 – compact ring main unit for network stations

The switchgear M19 is a compact ring main unit for the application in local network stations.
The installation takes place in compact stations as well as in the cellar area of buildings with partly difficulty access.



  • Switchgear with variable foundation for switchboard rooms with open cable installation.
  • Minimum room height requirement: only 2,05m!
  • Verification of pressure test: pressure rise at a room volume of 44 m³ without pressure release opening < 25 millibar.
  • In case of an arc fault, the reduction of the overpressure stress inside the switchboard room take place via the backside installed arc absorber. The hot gas cloud can be blow out on top or down inside the switchboard room.
  • Voltage test (verification of  isolating distance)
    • Test with AC-voltage of 28 kV at the bus bar, at the same time 42 kV AC-voltage at the cable tap over a time of 1 min.
    • Test with AC-voltage of 28 kV at the bus bar, at the same time 60 kV DC-voltage at the cable tap over a time of 10 min.
  • Easy upgrade with motor drive for a later remote control.
  • Optional: ring main panel with short circuit indicator
  • Optional: capacitive voltage indicator
  • Typicals: Ring main panel, transformer panel, bus coupler panel, bus riser- / measuring panel


Technical data:
Rated voltage 12kV
Rated current 630A
Rated power transfomer panel …1250kVA
Rated short time current 1s …25kA
Rated peak time current …63kA
Rated cable breaking current …150A
Arc proof withstand current …25kA
Loss of service continuity category LSC 2A
For room height ≥ 2,05m
Ambient temperature -25°C up to  +40°C
Dimensions W x H x D 540/640 x 1.930 x 780/860mm

Width of measuring panel: depends on the transformer type, 540mm or 640mm
Depth: depends on the pressure relief outlet (on top/down inside the switchboard room)

M19 Frontansicht Variante SockelM19 Frontansicht Variante UnterbauM19 RinkabelfeldM19 TrafofeldM19 Ring main unit