Frequency inverter for infinitely variable speed control of fans. It includes a mains filter and an additional terminal strip. The motor protection function is provided via thermal contact or PTC thermistor. Control inputs are galvanically isolated, PLC compatible, and freely programmable. Setpoint inputs include 0-5 V, 0-10 V, and 0(4)-20 mA with voltage and current offset calibration function. There is one analogue output for setpoint output at 0 - 10 V. It features six digital inputs, some of which are freely programmable. Signal outputs include two, partly freely programmable. There are two potential-free outputs for fault and operation signaling (changeover contact). Connections are made via metric screw connections: 2 x PG 12 and 2 x PG 16. Factory presets allow for 15 programmable fixed speeds. The service life is approximately 80,000 hours at 80 to 85% nominal load. It is suitable for product groups DSK, DAS, DSQ, EDR 56/63/71, and all DZ... with phase insulation (special version). The ST EC 010 can also be used for remote maintenance: MFU 14. Rated voltage is 3 x 380 V to 480 V (+/- 10%), with mains frequency of 50 Hz / 60 Hz and rated current of 14 A. The recommended motor power is 5500 W. Protection rating is IP 54, and the housing material is galvanized sheet steel. The color is light grey, similar to RAL 7035. The weight is 21.8 kg, with dimensions of width 260 mm, height 710 mm, and depth 300 mm. The ambient temperature range is -10 °C to 50 °C. It is suitable for duct ventilators and wall-mounted ventilators, but not for box fans, roof ventilators, heat recovery systems, domestic ventilators, centrifugal ventilators, or circulation ventilators.