Daikin RDT-135c Installation And Maintenance Manual

Contents

Daikin RDT-135c Installation And Maintenance Manual Manual pdf 59 page image

IM 738-2 57Preparing Unit for Operation: Adjusting Scroll DampersAdjusting Scroll DampersTwo sets of scroll dampers are provided in the housing of thetwin 15" x 6" supply fan to allow control of air volume to eachfan wheel. At the factory, these dampers are fully closed,unrestricting airflow. If fan paralleling occurs, correct it byloosening the adjustment screw on top of the fan housing (seeFigure 73) and slightly lowering the rod until air distributionbetween the fans is even.Figure 73. Scroll damper adjustmentAdjusting Supply Fan Thrust RestraintsThrust restraints are provided when housed double-width fansare mounted on springs. After the spring mounts are adjustedfor level operation when the fan is running, check the thrustrestraints. With the fan off, set the adjustment nuts so thespring is slightly compressed against the angle bolted to thefan housing frame. Refer to Figure 74. When the fan is turnedon, the fan moves back to a level position and the thrustrestraint springs compresses.Figure 74. Thrust restraint adjustmentAdjustment assemblyScroll damperNut"B"SpringlipWasher N u t " "anBulkheadJamNut"A"JamNut"A"ThrustRestraintAngleanHousingrameSeeDetail"A"Detail"A"Thrust restraint adjustment (with fan off)1. Loosen jam nuts “A.”2. Turn nut “C” until spring cup and washer contact thrust restraintangle.3. Turn nut “B” until spring is compressed by two turns of nut “B.”