The HLD03 (DD58) single phase meter is designed to meet the latest IEC 60521. The meter with mechanical construction complying BS 5685 is also available. With accuracy of class 2, it measures active energy in single-phase two-wire or three-wire alternating power grids. Connection is direct or by instrument transformers. The meter is KEMA certified and has passed the reliability test of EPRI, China. It is a reliable long service life meter. The average service life (MTTF) is 20 years and the maximal overload capacity is 667%Ib. The specifications of the meter can be tailored to customer requirements. Construction 1 Meter case Two types of the cases (protective-class I and II) are available. 2 Terminal block The terminal block is molded of Bakelite. The voltage test link can be located inside or outside of the meter case. 3 Driving element The driving element consists of a voltage element and a current element, both of which are fixed on the steel frame of fine magnetic conductivity. It has a load curve compensation device, low load and inductive load adjustment mechanisms. 4 Rotor The worm is an un-detachable part of the rotor shaft so that the mesh between the worm and shaft is improved. Both ends of the shaft are embedded with graphite bearing to ensure the long service life of the meter. 5 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. 6 Frame The frame is made of high-quality steel. Its surface is treated by negative electrophoresis to achieve excellent corrosion-proof. 7 Upper bearing The upper bearing consists of a guide pin and a brass sleeve, and is fixed into the meter frame by one screw. 8 Lower bearing Both Al-Ni-Co alloy and detachable hard ferrite magnetic bearings are available. 9 Register The register adopts heat- and abrasion-proof plastic gears and bearings. No lubrication of bearings is needed during the service life. The drum is made of polycarbonate, and is pyrographed and printed by UV resistant alumina to ensure non-depigmentation. 3. Technical data 1.Meter type HLD03 (DD58) 2.Applicable Standards IEC60521, BS5685 3.Accuracy Class 2(according to IEC60521) 4.Average service life (MTTF) 20 years 5.Basic current (Maximum current) A 1.5(6) 3(6) 5(20) 5(40) 10(60) 15(60) 20(80) 7.Rating current of transformer in 5A direct connection 8.Reference voltage Un 110V, 120V, 220V, 230V, 240V 9.Reference frequency fn 50 Hz, 60 Hz 10.Power losses in voltage circuit at 50 Hz Un 1.0 W/5 VA 11.Power losses incurrent circuit at 50Hz Un Ib<0.6 VA 12.Non-running with no-load 0.8~1.1Un 13.Staring current 0.5%Ib 14.Mean temperature coefficient: From 0.1Ib to Imax at unity PFFrom 0.2Ib to Imax at unity 0.5 lagging<0.08%/oC<0.12%/ oC 15.Insulation level: Withstand A. C. Voltage for 50 Hz, 1min Withstand impulse voltage 1.2/50us>2 kV (when bakelite base>4kV)>6kV (when bakelite base>8kV) 16.Rated load torque at unity PF, Ib 450uNm 17.Weight of rotor 24g 18.Weight of meter =1.5kg 19.Meter base Bakelite or steel 20.Meter cover Bakelite or transparent PC 21.Terminal cover Bakelite or PC 22.Register Cyclometer single, unidirectional, jumping 23.Option Reverse running stopper, pulse-sampling device