DTSD450 DSSD450three phase electric multifunction watt hour meter Class index: Active energy class 0. 5 1 reactive energy meter class 2 Clock error: Not more than 0. 5s/day Reference temperature: 23 degree Data protection: More than 10 year after power off Envirnment conditions: Working temperature -20degree 45 degree Utmost working temperature: -25 degree ~55 degree Relative humity: Less than 85% Demand statistics Record active max demand and its occurring time Demand statistics adopts slip method Max demand is stored as per month RS485 interface