Profile: NxtPhase T & D, Inc. provides HV instrument transformers up to 1200 kV. Our product line includes optical current transformer (AC or DC), merging unit, combined metering unit and flexible optical current transformers. Our COSI-NXCT is a lightweight dry-type insulator and window head design which allows pedestal mounting or suspension from a rigid bus. It's broad dynamic range makes this CT particularly suited for both high-precision metering and protection applications at the same time. The accurate measurement of DC and AC to 100th harmonic, and the measurement of phase angle is a must for new Smart Grid applications. Our Alstom COSI-NXCM system takes advantage of a conventional voltage transformer coupled with the wide dynamic range of the optical current transformer. The optical CT has the same specifications as the COSI-NXCT. Coupling capacitor voltage transformers (CCVTs) are used in high-voltage and extra high-voltage transmission systems to provide potential outputs to metering instruments, and to protective relays.