As a terminal of the smart grid,the smart meter has gradually enter into our lives.But the existing external circuit breaker of the electric energy meter,can only realize the automatic power off after the arrearage,when the payment is completed,the transmission needs to be operated manually. Therefore,although State Grid invested huge manpower cost,such problem still could not be solved, which greatly reduced customer experience.WiTXz-80 series of external circuit breaker(internal axis rotation) made by Longpo, not only can be reliably realized automatically switched on/off according to the payment,but also to achieve effective protection of the line and terminal equipment,meanwhile,feed signal about the switch-on-off. Products comply with“Q/GDW11421-2015 Technical specification of external circuit-breaker for electricity meters"issued by the State Grid and“Fee-controlled energy meter external low voltage circuit breaker technical specifications" issued by China Southern Powe