6. With the wheel temporarily pushed flush against the inside plenum
wall, the shaft can be centered on the hole, the inboard bearing
mounting bolts tightened and then the outboard bearing mounting
bolts tightened. This locates the shaft perpendicular to the plenum
wall and fan drive panel. Check level shaft.
If the fan is vertically mounted with inlet down, block the wheel and
shaft in place with wood blocking to prevent damage. Do not block
bearings to shaft yet.
7. Slide the shaft through the bearings and locate its drive end flush
with the end of the motor shaft. Make sure the bearing locking collar
is in position and tighten set screws to the bearing manufacturer’s
torque levels. See bearing manufacturer’s instructions enclosed for
8. Slide the wheel along the shaft and position it a distance from the
plenum wall, determined by the thickness of the insulation or the
gap designed in the plenum. This dimension is not critical. Any
extra length of shaft may extend through the hub without harm.
9. Install the inlet cone loosely on the housing or plenum structure,
attaching it only at four points until final adjustments are made.
Move the wheel along the shaft so that it slightly overlaps the inlet
cone. Position the inlet cone to be concentric to the wheel opening
with equal spacing in a radial direction all around. The inlet cone
can be firmly fastened at this time.
On a Heat Fan or a fan not operating at maximum static pressure, it
is satisfactory to have an axial
gap between the wheel and
inlet cone of 3/16" to 5/8"
depending upon the fan size.
This axial gap can be adjusted
by moving the wheel closer to
or farther away from the cone.
Position the wheel so that the
set screw over the key is at the
bottom. Torque the bottom set
screw first and then the oppos-
ing set screw next. Torque all
set screws per the Torque Values chart.
Recheck the wheel cone to inlet cone clearance.
Mount the adjustable motor base on the drive panel gusset as
shown in the illustration. Mount the motor on the adjustable motor
base and adjust the base height for the approximate center distance
of the V-belt being used.
Loosely install the fan and motor sheaves and the belts. Tighten the
fan sheave first, then align the motor sheave to the fan sheave. The
fan and motor shafts must be parallel. See V-belt Drive section of
this manual for sheave alignment and installation.
If the fan handles air above 300° F, install the shaft-cooling wheel by
either centering it in the space between the inboard bearing and drive
panel, or by setting it in the recessed area in the drive panel. Two self-
tapping bolts clamp the cooler to the shaft. Install all shaft, cooling
wheel, bearing guards and belt guards as required.
If the fan has been provided with an Inlet Volume Control (IVC), it is
mounted in the inlet cone and no further adjustments are required
except to hook up the operating lever to the Customer’s Control.
The IVC should be checked for correct rotation. Looking at the IVC
from the inlet side with IVC blades half closed, the blades should
pre-spin the entering air in the same direction as the fan wheel is
Chicago Blower requires that all appurtenances, including ductwork
or stacks, which are attached to the fan inlet or outlet, be inpen-
dently supported, unless prior approval has been obtained from
Chicago Blower. Excess dead loads or wind loads can distort the
fan housing causing misalignment and possible failure. Flexible
connections are also necessary to prevent duct expansion or
movement from adding loads to the fan.
NOTE: For High Temperature Applications – The fan should not be
shut off until the airstream temperature is below 200°F.
1. Drive panel must be mounted on a rigid and substantial foundation on
the plenum chamber wall. Careful design of the mounting structure is
needed to insure vibration-free operation. If the structure is not rigid,
harmonic vibrations occur. On some “soft” structures, field touch-up
balancing may be necessary to
balance the complete system struc-
2. Make sure the wheel rotation is correct (
clockwise or counterclock-
wise as viewed from the drive side
) for the planned discharge from
the plenum chamber or accessory housing.
3. If the accessory housing is being used, it should be installed flush against
the inside plenum wall before the wheel is put on the fan shaft. Fasten
to the plenum wall by bolting or stitch welding.
4. Check shaft and keyways for nicks from handling. File off. Slide the
wheel onto shaft end with the longest keyway. Insert the key and lightly
tighten the wheel set screws with the wheel positioned half way along
5. From inside the plenum, push the drive end of the drive shaft through the
plenum shaft hole and through the inboard bearing bracket. With the
shaft end halfway to the outboard bracket, slip one bearing on the shaft.
Then push the wheel-shaft assembly all the way through and install the
drive bearing. Use mounting hardware as shown below. Both bearings
are the same.
FLANGE MOUNT BEARING DETAIL
PILLOWBLOCK BEARING DETAIL
SET SCREW TORQUE VALUES
Steel Grade 2
*SHIMMING UNDER BEARING FEET IS
NECESSARY TO VERTICALLYALIGN BEAR-