Secondary Equipment in Distribution Rooms refers to devices including DTU terminals, relay protection devices and background communication systems, which work alongside primary high and low voltage main equipment in the power distribution hub to perform power distribution . Secondary Equipment in Distribution Rooms refers to devices including DTU terminals, relay protection devices and background communication systems, which work alongside primary high and low voltage main equipment in the power distribution hub to perform power distribution . Secondary Equipment in Distribution Rooms refers to devices including DTU terminals, relay protection devices and background communication systems, which work alongside primary high and low voltage main equipment in the power distribution hub to perform power distribution, equipment management and. This page is a practical guide for designing feeder automation terminals (FTU, DTU and TTU) with the right mix of sensing, communication, power, security and IC choices. It helps map real grid scenarios into a robust architecture, a realistic checklist and brand-ready component selections. Feeder. Widely used in ring main units, small switching stations, and prefabricated substations, this system can be integrated with distribution network automation master stations and sub-station systems to collect and control power data from multiple lines, detect faults, locate and isolate fault zones. Employ the SEL-TMU for remote data acquisition in substations with Time-Domain Link (TiDL®) technology systems. It can share data with up to four TiDL relays. Provide high-speed transformer diferential protection for up to five terminals as well as advanced monitoring, metering, automation, and. Protective relays and devices have been developed over 100 years ago to provide “last line” of defense for the electrical systems. They are intended to quickly identify a fault and isolate it so the balance of the system continue to run under normal conditions. The selection and applications of. Advanced transformer protection helping extend asset life.