Description

General The DT*8 three-phase four-wire meter is designed to meet the latest IEC****1 and BS EN ****1 standards for measuring active energy in three-phase four-wire alternating current power grids. Connection is direct or by instrument transformers. The meter is KEMA certified. It has an average service life (MTTF) of *0 years and maximum overload capacity of **0%Ib. Constructions Meter case It meets the protection requirements set by protection class IP*3 of IEC****9. The series types of cases and terminal covers are available. Terminals & Terminal block Terminals: The connection terminals are made of nickel-plated brass with features of high mechanical strength, good conductivity and corrosion-resistance. Terminal block: The terminal block is injection molded of heat- and fire-resistant bakelite. The voltage test link can be located inside or outside of the meter case. Driving system The driving system employs three single electromagnet elements, all of which are mounted on the meter frame with three screws. Each electromagnet element consists of voltage element, current element and connection board. In addition, the voltage electromagnet has low load and inductive load adjustment mechanisms. The current element employs a simple and reliable load curve compensation mechanism to ensure the flat characteristic curve. Rotor The rotor shaft is turned of high strength aluminum alloy. The upper end of the shaft is pressed with a worm which is made of thermoplastic, and the lower end is embedded with a graphite bearing which is self-lubricative and friction-resistant to ensure long service life of the meter. Braking element The magnet is made of AlNiCo5 alloy and designed as U-shaped so that the effect of short-time over currents upon the magnet is negligible. A temperature compensation plate, made of a special alloy, is embedded in the braking magnet. The rotor speed can be a