2
CV IO&M
B51161-003
Tolerance
Center
Distance
Maximum
Gap
Up thru
12”
1/16”
12” up
through
48
1/8”
Over 48”
1/4”
OFFSET
ANGULAR
OFFSET/ANGULAR
A
W
X
Y
Z
B
CENTER
DISTANCE
(CD)
GAP
GAP
Pulley Alignment
Pulley alignment is adjusted by loosening the motor pulley
setscrew and by moving the motor pulley on the motor shaft.
Figure 2 indicates where to measure
the allowable gap for the drive align-
ment tolerance. All contact points (in-
dicated by WXYZ) are to have a gap
less than the tolerance shown in the
above
Tolerance
table.
When the pulleys are not the same
width, the allowable gap must be
adjusted by half of the difference in
width.
Figure 3
illustrates using a car-
penter’s square to adjust the position
of the motor pulley until the belt is parallel to the longer leg
of the square.
Final Installation Steps
1. Inspect fasteners and setscrews, particularly fan mounting
and bearing fasteners, and tighten according to the recom-
mended torque shown in the table below,
Recommended
Torque for Setscrews/Bolts
.
2. Inspect for correct voltage with voltmeter.
3. Ensure all accessories are installed.
4. Test the fan to be sure the rotation is the same as indicated
by the arrow marked
Rotation.
Wheel Rotation
Test the fan to ensure the rotation of the wheel is the
same as indicated by the arrow marked
Rotation
.
115 and 230 Single Phase Motors
Fan wheel rotation is set correctly at the factory. Chang-
ing the rotation of this type of motor should only be at-
tempted by a qualified electrician.
208, 230, and 460, 3 Phase Motors
These motors are electri-
cally reversible by switching
two of the supply leads. For
this reason, the rotation of
the fan cannot be restricted
to one direction at the fac-
tory. See
Wiring Diagrams
for specific information on
reversing wheel direction.
NOTICE! Do not allow the fan to run in the wrong di-
rection. This will overheat the motor and cause seri-
ous damage. For 3-phase motors, if the fan is running
in the wrong direction, check the control switch. It is
possible to interchange two leads at this location so
that the fan is operating in the correct direction.
To maintain good working condition of a CV when it is
stored outdoors, or on a construction site, follow the addi-
tional steps below:
• Cover the inlet and outlet, and belt tunnel opening to prevent
the accumulation of dirt and moisture in the housing
• Periodically rotate the wheel and operate dampers (if supplied)
to keep a coating of grease on all internal bearing parts
Installation
To prevent damage to the fan during shipping, motors 5 HP and
larger, and extremely heavy motors (cast iron or severe duty) are
shipped loose and must be field mounted by bolting the motor on
the motor mounting plate in the existing mounting slots.
UCV Fan Installation
The fan support (roof curb) should provide a level surface for
installation. If the roof is pitched more than 1/2:12, a sloped curb
must be used to correct for the incline. If the unit is installed on
a non-level surface, the damper door pivot should be positioned
perpendicular to the peak of the roof.
Place fan over roof opening. Secure the fan with lag screws,
anchor bolts, or other suitable fasteners.
Wiring Installation
Direct Drive
Wire the electrical box on the blower housing.
Belt Drive
The motor can be wired directly since the motor is external to
the fan.
Leave enough slack in the wiring to allow for motor movement
when adjusting belt tension. Some fractional motors have to be
removed in order to make the connection with the terminal box at
the end of the motor. To remove motor, remove bolts securing mo-
tor base to power assembly. Do not remove motor mounting bolts.
NOTICE! Follow the wiring diagram in the disconnect
switch and the wiring diagram provided with the mo-
tor. Correctly label the circuit on the main power box
and identify the closed switch to promote safety (i.e.,
red tape over a closed switch).
Belt and Pulley Installation
Belt tension is determined by the sound of the belts when the
fan is first started. The belts will produce a loud squeal, which dis
-
sipates after the fan is operating at full capacity. If belt tension is
too tight or too loose, lost efficiency and damage can occur.
Do not change the pulley
pitch diameter to change
tension. The change will re-
sult in a different fan speed.
1. Loosen the motor
plate adjustment nuts
on motor base and
move motor plate in
order that the belts
can easily slip into the
grooves on the pul-
leys. Never pry, roll,
or force the belts over
the rim of the pulley.
2. Adjust the motor plate
until proper tension is
reached. For proper
tension, a deflection of approximately 1/4” per foot of center
distance should be obtained by firmly pressing the belt. See
Figure 3
.
3. Lock the motor plate adjustment nuts in place.
4. Ensure pulleys are properly aligned. See
Pulley Alignment
.
1 foot
1/4 inch
Figure 2
