-DD862 SINGLE PHASE METER IS DESIGNED TO MEET THE iec60521-1998 and BS EN60521 standards for both indoor and outdoor installations, the meter with mechanical construction complying BS5685 is also available with accuracy of class 2 it measures active energy in single phase two wire or three wire alternating current power grids, connection is direct or by instrument transformers, the average service life, is 10 years and the maximum overload capacity is 500%ib,
Construction.