Application DD28 single-phase watt-hour meter is a kind of induction meter, which is applicable to measure the rated frequency 50Hz and power loss in electrified wire netting. All technical targets are completely conformed to National Standard GB/T15283-94 and Intermational Standard IEC 521. Structure and features The meter has separable electromagnet and the bearing has four kinds; single-jewel, dual jewel, magnetic thrust and magnetic floating. The case has three kinds; aluminum, plastic and glass. The die-casting frame is alloy aluminum with excellent mechanical strength.