The Helios TSD 0.8 is designed to control the speed of one or multiple 3‑phase fans by reducing the supply voltage. It offers selectable voltage levels of 0, 80, 140, 280, and 400 volts to adjust fan speed precisely. The unit is housed in an IP54-rated enclosure, providing protection against dust and splashing water, and operates on a frequency of 50/60 Hz. This controller allows flexible and efficient fan speed management in various ventilation applications.