non-contact current transformer

The CMD is not limited to substation applications, being equally well suited for application on distribution lines, subtransmission lines, transmission lines, and EHV transmission lines.  In line applications the CMD provides the functions of real-time line current monitoring and phone home fault locating (fault circuit indicator [FCI]).  For its line applications the CMD is highly useful in assisting utilities in meeting their NERC reliability requirements through the reduction of SAIDI and CAIDI minutes. 

SSIPowers CMD non-contact current transformer measures three-phase current at high voltages to protect power systems and to provide critical real-time information to power system operators. Its relaying accuracy class design utilizes sensors and electronics installed in its three-phase current wand to measure magnetic field density and to convert these values into electric currents, providing a secondary current output to a microprocessor-based protection relay or to an RTU. These measurements are accomplished at ground potential with the CMD current measuring device having no physical contact with the conductor (cable or bus) that it is measuring. Unlike traditional CTs, it is immune to CT saturation, making the CMD non-contact current transformer not only more reliable than freestanding current transformers but also less costly and less space consuming. It readily mounts on new or existing equipment without requiring any new structures or foundations. The three-phase current measuring capability of this single device allows it to substitute for a set of three freestanding current transformers. The CMD is well positioned to assist utilities who are implementing IEC 61850 substation automation programs.

  CMD
 Three-Phase Non-Contact Non-Saturating Current Transformer