Trust in our tailor-made solutions for your unique needs

Trust in our tailor-made solutions for your unique needs


800 kV / 4000 A

Trench Optical Current Transformers are a revolutionary alternative to conventional current transformers, providing an advanced solution for measurement and protection applications, based on cutting-edge optical sensing technology.


  • No ambient temperature limitation
  • Filled with nitrogen compressed slightly above ambient pressure – to avoid ingress of moisture or other objects


  • Aluminum housing with glass ring sensors
  • Insulators made of composite materials that can withstand mechanical stresses, including tensile, short-circuit, and seismic forces
  • A connection box for attaching a TOCT to the station’s fiber optic cables
  • A signal processing unit, merging unit, containing a light source, photodetectors, and signal processing. It comes with up to three individual channels for measurement


Suitable for low-temperature applications at -50 °C and below, In IEC 61850-9-2 compliant digital substations, thanks to digital “process bus” interface with long-distance fiber optic cable, which offers maximum flexibility for applications


Regenera™ is our holistic approach to protecting ecosystems, fostering environmental harmony and promoting a circular economy.


Trust in our tailor-made solutions for your unique needs

Wide application range

Optical current sensor enables use of only one type of TOCT for a wide range of protection and measurement applications.

More compact CT Design

Small and light-weight units compared to conventional CT design.

Improved operational safety

Galvanic separation between primary and secondary side.

GWP of Zero for insulation gas

Zero CO2 equivalent compared to 24.300 kg CO2 equivalents by using conventional gas.

Reduced cabling effort

Single fiber-optic cable instead of several copper cables with large cross-sections.

Passive system

No electronic components needed within the TOCT.