low-voltage metering power custom must install the appropriate specifications of three-phase meters,larger coustom must also install the current transformer(CT),which brings difficulty in management and metering equipment,the phenomenon of stealing electricity and leakage of metering have occurred,but the 2(200)A three-phase meters could unify the specifications of meters,simplify the workload of inspecting meters、distribution、installation and maintenance,while increase the difficulty of stealing electricity,improve the reliability of metering equipment and system.