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Thefansaremonitoredbymeansofflowsensors.Ifnoairflowisregisteredafterashortdelaytimehas
expired,thesystemisswitchedoffandanerrormessageisgenerated,whichcanbeacknowledgedby
pressingtheoffbutton.
Fanmonitoringrequiresananalyzercircuitwithseveralswitchingdevices,inadditiontotheflowsensors.
AsinglexLogicdevicecanreplacethisanalyzercircuit.
7.3.2TheschemeofxLogic
Thecircuitdiagramofventilationsystem:
Requiredcomponents:
l K1 Maincontactor
l K2 Maincontactor
l S0(makecontact) Offbutton
l S1(makecontact) Onbutton