Centrifugal Inline Fans
7
®
WARNING
Correct direction of wheel rotation is critical. Reversed
rotation will result in poor air performance, motor
overloading and possible burnout.
AVERTISSEMENT
La turbine doit impérativement tourner dans le bon
sens. Une rotation en sens inverse entraînerait de
mauvaises performances de soufflage, une surcharge
du moteur voire un grillage du moteur.
Pre Start-Up Checks
1.
Check all fasteners for tightness.
The wheel
should rotate freely and be aligned as shown in
Figure 9. Wheel position is preset and the unit is
tested at the factory. Movement may occur during
shipment, and realignment may be necessary.
Centering can be accomplished by loosening
the bolts holding the inlet (venturi) panel and
repositioning. Wheel and inlet cone overlap can be
adjusted by loosening the setscrews in the wheel
and moving the wheel to the desired position.
2.
Wheel Rotation:
Direction
of wheel rotation is critical.
Reversed rotation will result in
poor air performance, motor
overloading and possible
burnout. Check wheel
rotation by momentarily
energizing the unit (all direct
and belt drive fans have
clockwise wheel rotation
when viewed from top of fan). Rotation should be
clockwise as shown in Figure 10 and correspond
to the rotation decal on the unit. If wheel rotation is
incorrect, reverse two of the wiring leads for 3 phase
or check motor wiring for single phase. Fan rpm
should be checked and verified with a tachometer.
C
lo
c
k
w
is
e
Figure 10
G
H
Wheel Overlap Dimensions
Size
Direct
Drive
Belt
Drive
G - Overlap
in.
(mm)
H - Gap
in.
(mm)
60-95
x
-
1/8
(3)
97-99
x
1/4
(6)
100-160
x
1/4
(6)
-
70-160
x
1/4
(6)
-
180-240
x
3/8
(10)
-
300-420
x
1/2
(13)
-
Figure 9
Belt Span
Deflection =
Belt Span
64
Figure 13
Figure 11
CORRECT
WRONG
WRONG
WRONG
5.
For Belt Drive Fans:
Belt tension can be adjusted
by loosening four fasteners marked “R” on the drive
frame. (Refer to Figure 12). The motor plate slides on
the slotted adjusting arms. Belt tension should be
adjusted to allow 1/64 inch of deflection per inch of
belt span. For example, a 15 inch belt span should
have 15/64 inch (or about 1/4 inch) of deflection with
moderate thumb pressure at mid-point between
pulleys (see Figure 13). Over-tightening will cause
excessive bearing wear and noise. Too little tension
will cause slippage at start-up and uneven wear.
3.
Vibration Isolators:
After fan is moved to desired
location, punch out the four knockout holes which
are located on the unit top and bottom panels.
Assemble the brackets to the unit according to
the appropriate drawings on page 6 and refer to
respective parts list on page 11. Make certain all
connectors are tight and that all washers are in.
4.
For Belt Drive Fans:
If adjustments are made, it
is very important to check the pulleys for proper
alignment. Misaligned pulleys lead to excessive belt
wear, vibration, noise, and power loss; Figure 11.
R
Figure 12
NOTE: Identical
fasteners on
opposing side must
also be loosened.
