General Data Rated input voltage 230 Vac Rated output voltage 0 ‑ 250 Vac Rated current 0.8 ‑ 20 A Insulation class B Maximum ambient temperature 45 °C Degree of protection IP 00 Advantages Stepless adjustment of the AC voltage from zero to the maximum value Self‑cleaning of the exposed contact tracks 4‑point flange mounting Rotary knobs and scales optionally available Standards Variable transformer to: VDE 0552 Variable auto transformer for continuous adjustment of AC voltages or currents under load.