The transmitter of the FDS 100 set with DIBt approval monitors the window position and transmits the information by radio to a built-in receiver with a potential-free 5 A changeover relay. In this way, an exhaust air system can only be operated with a tilted or open window if it is ensured that sufficient fresh air flows into the room and thus no negative pressure is created that could draw dangerous and toxic carbon monoxide from a combustion site.

DESCRIPTION
The exhaust air system can only be used when the window is open and the necessary supply air can flow into the room. A transmitter on the window sash monitors whether the window is open or closed and transmits this information by radio to the receiver. The receiver only releases the power supply when the window is tilted or open.
Lighting independent of the window position:
The one line that safely switches off the fan motor in all operating states is disconnected and reconnected to the normally open contact (terminals 1 and 2) of the FDS 100.
Control of a control contact:
Some manufacturers of exhaust air systems provide a contact that only controls the fan motor, often fitted with a wire jumper when delivered. This jumper is released and switched with the normally open contact of the FDS 100.
Second window (OR):
At least one window must be open for the exhaust air system to be switched on. For this purpose, the FDS 100 SET is connected to the additional transmitter FDS 098 or FDS 098 L (note dimensions!) for the second window.
Second window (AND):
Two windows must be open at the same time so that the exhaust air system can be switched on. This requires two independent FDS 100 SETs with different coding.

Parameter Name	Parameter Value