Daikin RDT Installation And Maintenance Manual page 48

Adjusting Scroll Dampers
Two sets of scroll dampers are provided in the housing of
the twin 15ʺ × 6ʺ supply fan to allow control of air volume to
each fan wheel. At the factory, these dampers are fully closed,
unrestricting airflow. If fan paralleling occurs, correct it by
loosening the adjustment screw on top of the fan housing (see
Figure 58) and slightly lowering the rod until air distribution
between the fans is even.
Figure 58: Scroll Damper Adjustment
Adjustment assembly
IM 893-10 • ROOFPAK SINGLEZONE UNITS
Adjusting Supply Fan Thrust Restraints
Thrust restraints are provided when housed double-width
fans are mounted on springs. After the spring mounts are
adjusted for level operation when the fan is running, check
the thrust restraints. With the fan off, set the adjustment nuts
so the spring is slightly compressed against the angle bolted
to the fan housing frame. Refer to
turned on, the fan moves back to a level position and the thrust
restraint springs compresses.
Figure 59: Thrust Restraint Adjustment
Scroll damper
Jam nut A
Thrust restraint adjustment (with fan off)
1. Loosen jam nuts "A".
2. Turn nut "C" until spring cup and washer contact thrust restraint
angle.
3. Turn nut "B" until spring is compressed by two turns of nut "B".
4. Tighten jam nuts "A".
48
P
reParIng
Figure
See Detail A
Nut B
Spring clip
Washer
Nut C
Jam nut A
Thrust restraint angle
Fan housing frame
Detail A
u o
nIT for PeraTIon
59. When the fan is
Fan bulkhead
www.DaikinApplied.com