HU Hygrostat

Room humidistat HU used for demand control of fans or residential air handling units. Enables humidity control devices to be switched on or switched fan speed according to needs. Monitoring and controlling relative air humidity in rooms, suitable for wall mounting. Variable relative humidity as set point based on printed scale in % rH. Set point adjuster on front with setting range 30…90% rh. Measurement is effected using a sensor made of stabilised synthetic textile tape. The Housing is of pure-white, flame-retardant thermoplastic (RAL 9010). Included micro switch with fixed switching difference XSd (6% rh). Screw terminals for wires of up to 1.5 mm². Switching capacity: up to 3 A. When the relative air humidity is increasing and after the upper change-over point is reached, contacts 1-2 are opened and 1-3 are closed. Set pint XSd corresponds to the upper change-over point. The contacts are reset when the humidity value falls below the upper change-over point again by the amount of the fixed switching difference. The ageing effect of the measuring element causes the change-over point to shift gradually and permanently. Therefore, recalibration may be necessary.