Only calibrated meters are permitted for electricity billing in accordance with paragraph 25 of the German Calibration Act. Non-compliance is an irregularity in accordance with paragraph 19. RS485-bus two-way three-phase meter. Maximum current 3x80A, standby-loss only 0.8 Watt at L1 and each 0.5 W at L2 and L3. DIN-EN 60715 TH35 DIN rail mounting device in installation cabinets with protection class IP51. 4 divisions = 70mm wide, 58mm deep. Accuracy class B (1%). With RS485 interface. The directly measuring three-phase meter measures the active energy by means of the currents flowing between the inputs and outputs. The intrinsic consumption of only 0.8 watt or 0.5W active power per path is not measured and not displayed. The active energy is added depending on the sign. Positive power in the counter means energy reference, a negative power means energy supply. The energy measurement is performed by balancing. If the energy reference (P positive) is greater than the power supply (P nega