KA IMO 2021 6 V2.1

systemair 19
• Attach the sealing plates to the sides of the device where the two roofs meet and screw them on. Since the left and
rightpiecesaredifferent,makesurethatthe»L«fromcoveralwayslooksintheotherdirectionthan»C«fromthe
roof and the gap between the pieces of the roof is always covered.
• Clean the roof of the drill chips and dirt accumulated during installation.
2.3.3 Connection of ducting
Caution
Inallcases,theairhandlingunitmustbeconnectedtotheductingbymeansofexibleconnections.The
exibleconnectionsshouldalwaysbealmostfullystretched(50-90%).
In the case of a centrifugal fan, the dimensions of the duct should be similar to those of the air outlet
opening onto the fan, in order to avoid or minimise losses due to turbulence.
Inspecialcases,e.g.withverticalductruns,buoyancyeffectsmayinduceanairowthatdrives(rotates)
afanimpellerevenwiththedrivemotoroff.Therotatingimpellerposesariskofinjuryduringrepairor
maintenanceworks.Thisdangercanbepreventedbyapplyingmotordriveswithcounter-springsthat
automatically shut the dampers also in the event of power supply failure.