Application DD910 Series Watt-hour is the inductive AC watt-hour meter novel in design, reasonable in construction, high overload, high in stability, long in service life, and easy in adjustment and calibration, With these electrical and mechanical characteristics ,it satisfies the demands of large electrical energy required by the moden department, It is designed and manufactured according to IEC 521 standard. Main functional features 1.The electromagnetic system and magnetic circuit specially treated with the technology adopt the imported steady magnetic iron core made by the silicon sheet, which straighten the error curve of the meter. 2.The brake magnetic steel offers the biplane-cheek type construction, which can decrease the vibration caused by the parasitic torque on the rotating disk, and easily clean the dust in the magnetic steel. 3.The voltage coil is sealed by employing the epoxy resin against the affectioin of humidity, and adopts the insulated plastics in the voltage and current colis as the sheath, which ensures the meter?s life and the electrical safety performance. 4.The meter bearing comprises of the suspended magnetic bearing and the hard graphite bush with self-lubrication, and offers the stainless steel needle guide construction, by which the friction torque is greatly decreased, with the stability and reliability of the meter increased. Main technical pareameter 1.Executive standard: Each performance meets the technical requirements of GB/T 15283-94 (IEC 521-1998) standard for the single-phase watt-hour meter.