5
Centrifugal Single-Width Blower
®
Installation
Move the fan to the desired location. Check and
tighten fasteners throughout the unit and then fasten
securely through mounting holes provided in the base
angles. The unit must be set level (shimming may be
necessary). Flexible duct connections and vibration
isolators should be used where noise is a factor.
The motor voltage and ampere rating must be checked
for compatibility with the electrical supply prior to final
electrical connection. Supply wiring to the fan must
be properly fused, and conform to local and national
electrical codes.
The discharge is factory set as specified by customer
order, however, certain sizes can be rotated to other
discharge positions in the field if necessary. If rotating
the fan housing, accommodations may need to be
made for the fan to drain properly. Removal of the
housing bolts allows the discharge to be rotated to the
clockwise positions above. For DB discharge position,
a portion of the frame angle must be removed.
Fan rotation is always specified from the drive side of
the housing.
Discharge Positions
To avoid motor overheating and possible burnout,
motor load amperes should always be checked and
compared to nameplate rating when fan speed is
increased.
Alignment of Pulleys and Belts
Check pulleys and belts for proper alignment to avoid
unnecessary belt wear, noise, vibration and power
loss. Motor and drive shafts must be parallel and
pulleys in line as shown in Figure 1.
Do not force belt(s). Forcing the
belt(s) will break the cords and
cause belt failure
Deflection = Belt Span
64
Slack
Side
Belt
Span
CORRECT
WRONG
WRONG
WRONG
CORRECT
WRONG
WRONG
WRONG
Figure 1
V-Belt Drive Installation
1. Remove the protective coating from the end of the
fan shaft using mineral spirits or another similar
solvent. Check to ensure that the shaft is free of
nicks and burrs.
2. Slide sheaves on shafts. Do not drive sheaves on
as this may result in bearing damage.
3. Align fan and motor sheaves with a
straight edge or string and tighten.
4. Place belts over sheaves. Do
not pry or force belts, as this
could result in damage to
the cords in the belts.
5. Adjust the tension until
the belts appear snug.
Run the unit for a few
minutes and allow the
belts to “set” properly.
6. With the fan off and disconnect locked out, adjust
the belt tension by moving the motor pivot plate.
When in operation, the tight side of the belts should
be in a straight line from sheave to sheave with a
slight bow on the slack side.
FAN
MOTOR
FAN
MOTOR
Aligning Sheaves with
a Straight Edge
Wheel Rotation
Rotation direction of the wheel is critical. Incorrect
rotation will result in reduced air performance,
increased motor loading and possible motor burnout.
Check wheel rotation by momentarily energizing the
unit and noting if rotation
is in the same direction
as the airflow at the outlet
and conforms to the
rotation decal affixed to
the unit.
Wheels as viewed from
the drive side:
R
o
ta
tio
n
R
o
ta
tio
n
Rotation
Rotation
Backward Inclined
Forward Curved
Airflow
Airflow
Backward Inclined
Forward Curved
Airflow
Airflow
These are the original drawings on the Illustrator file
when I opened it. The IOM had the wheel layered on
top of the scroll.
I will incorporate the
wheel on the scroll
without creating
an additional
layer in the
InDesign file.
April 19, 2011
I positioned the wheels onto the scroll outline. The forward curved wheel was mirrored and
positioned on the scroll above. This is how was done in the InDesign Utility Fans IOM file.
The wheel was laid on top of the scroll within the InDesign file. Better to do this within Illustrator.
barb w
R
o
ta
tio
n
R
o
ta
tio
n
C
lo
ck
w
is
e
R
ot
at
io
n
Airflow
Airfoil
Centrifugal
Backward Inclined
Forward Curved
Airfoil
TH
UB
BH
Method for Centering Wheel
On belt drive units, centering can be accomplished
by (a) loosening the inlet cone bolts to move the inlet
cone or by (b) loosening the bearings in order to
move the shaft. Wheel and inlet cone overlap can be
adjusted by loosening the wheel hub set screws and
moving the wheel to the desired position. Tighten all
fasteners and set screws securely and realign drive
pulleys after adjustment.
