Suit for 110V, 120V, 220V, 230V, 240V AC low voltage system Measure V, I, P, Q, S, PF, kWh, kvarh, Multi-tarif energy value 7 +1 digits LCD display (9999999.9 kWh) Record historical energy for latest 31 days (per 15min.), latest 12 months and latest 10 years KWh accuracy class 0.5s or 1.0 Support over-voltage timing, under-voltage timing, over-current timing function 2 LED indicates pulse output (Settable for kWh or kvarh) LCD display prompt for phase sequence error 3 keys for programming, 35mm DIN rail installing, standard DIN ED5002 RS485 port, MODBUS-RTU or DTL645 protocol (selectable) Standard: IEC62053-21/ 23