Major technical data: Accuracy class: 1. 0 Power consumption: <4VA Rated voltage: 220V Basic current: 2. 5(10)A 5(25)A 10(40)A Precision: 1. 0 High overload: 5times Operating time: >20years Main Function: 1. Measurement of pre-purchase of single-phase 50Hz active power and power consumed. 2. Pre defined maximum load, overload warning and power off. 3. Warning of remained prepaid amount to remind user for payment. 4. Re-read power consumed, remained prepaid amount, cumulative negative power and number of prepayments and power. 5. Power off at 0 power 6. Parameter transferring through IC card. Features: 1) High accuracy, reliability, overload capability 2) Low power consumption 3) SMT technology and re-flow soldering technology 4) Light weight, small size, easy to install