Cooling fan for Hanovia medium-pressure ultraviolet disinfection systems, 230 V, 120 mm square frame, part 750004-0240. Medium-pressure UV lamps run their control gear hot, and the fan is what holds the electrical enclosure within its rated ambient. A failed fan does not stop the system immediately, so it is usually found either at service or after a thermal trip — worth treating as a scheduled replacement rather than a breakdown item. Reference number 22152-0319.