With the extension of the period of validity of the general building approval Z-41.3-322, new requirements were established for use and maintenance as well as for utilization without ventilation ducts that are connected on both sides (over-current device). Permission from the building supervisory board is required for utilization as an over-current device. These have been taken into account in our new leaflet no. 4/8/D/7 (german version), as well as in our new assembly, commissioning and maintenance instruction MI-4/8/D/7 (german version). The print versions of both documents can be requested immediately via sales department (E-Mail).