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Cofimco Fan – U Style Hub
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User Manual 00-1352
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Fan Components
1
2
3
4
Figure 1—Typical Fan Assembly
2
Order No. ___________________________________
Trial Pitch Angle ______________________________
Final Pitch Angle _____________________________
Speed-rpm __________________________________
Contract hp _________________________________
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Note
Fan Assembly Instructions
The following instructions apply to installations having straight
bores or tapered output shafts without split taper bushings.
It is convenient to preassemble the fan prior to installation on
the driving shaft.
1—Select a large open area corresponding to the fan diameter.
2—Position the fan hub 1 in the center of the work area with the
blade sockets up.
3—Place a blade 2 in a blade socket on the hub. On fans where the
blades overlap at the hub be sure to have the leading edge under
the trailing edge of the forward blade. Refer to Figure 2.
4—Ensure the blade shank safety collar is inboard of the inner hub
rim. Refer to Figure 3.
5—Position the small U-bolt 3 over the blade shank and through the
TRAILING
EDGE
Figure 2
LEADING
EDGE
hub. Finger tighten the self-locking nut with flat washer onto U-bolt
threads. Progressively tighten each leg of the U-bolt until blade is
held in place.
6—Pull blade radially outward to be certain the shank safety collar
is in contact with hub inner ring. Refer to Figure 3.
7—Repeat steps 5 and 6 as required with the large outer U-bolt 4.
8—Repeat steps 3 through 7 for all blades.
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3
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9—Progressively tighten each side of the U-bolt until the blades are
barely able to move when twisting the blade.
BLADE
SAFETY COLLAR
INNER HUB
RIM
Figure 3
Fan Installation Instructions
1—Be sure motor is locked out.
2—Clean the hub bore and driving shaft extension for the full length
of the key.
3—Insert the key in the keyway. The top of the key must be below
the top of the shaft by not more than 1/8″ (3 mm) . The key is a tight
fit across the width and must never be altered.
4—After cleaning, apply a coat of anti-seize compound to the engagement portion of the shaft.
5—Raise the fan assembly above the shaft and slowly lower the hub
onto the shaft with the keyways aligned. Make certain the key does
not slide down during installation.
6—Install the Hub Retention Cap Screw with Lock Washer. Torque
hub retention cap screw to 40 ft·lb
(54 N·m).
ƒ
4
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Note
Adjusting Fan Blade Pitch
The trial pitch is the calculated setting for design conditions
(water rate , heat load, air density, and brake horsepower). The trial
pitch is provided by SPX (see page 2).
1–Select a position on the fan circumference and rotate each blade
to this common location when setting or checking blade pitch. Support the blade tip to maintain a common rotation plane while setting
the fan pitch. The pitch is set 3/16″ (5 mm) inboard of the blade tip
by placing a protractor on top of a parallel sided straight edge that
extends across blade width as shown in Figure 4.
2–Be sure all blades are positioned correctly on hub, then set the
pitch. Blades should be within ± 1/4° of the desired pitch angle. After
the desired setting is obtained, progressively tighten the hardware
according to Table 5. Recheck the pitch angle. If required, loosen
the hex nuts and reset the pitch as necessary until the proper pitch
angle is obtained.
Figure 4
Table 5
Bolt
Diameter
mm
14
16
Torque Wrench Setting
ft·lb
138
ƒ
87
N·m
93
188
5
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Fan Maintenance
Preventative maintenance will prolong useful life and assure continued trouble-free operation. After the first week and subsequently
at six month intervals:
• Torque all hardware to specications referenced in this manual.
• Visually inspect the fan for airborne debris damage, contact with
fan cylinder segments, and corrosive attack. Correct any situations
determined detrimental to fan operation.
• Remove any accumulated scale or dirt.
• Clear blade drain holes at fan tip.
Service
Proper identification of your fan is necessary to insure you receive
correct replacement parts. The Marley cooling tower serial number
can be used to determine the fan and any components installed and
maintained as original equipment on a Marley cooling tower. Please
provide the Marley sales representative the necessary information
when ordering replacement fans or components.
Blades can be replaced without rebalancing the entire fan.
If rebalancing is desired, contact the Marley sales representative in
your area.
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Motor Load
The corrected horsepower should be close to but not exceed the
contract horsepower specified by SPX. Determine corrected horsepower using the following equation.
Actual volts and amperage must be obtained with the fan running
and the specified rate of water flowing over the tower after the motor
and Geareducer have reached operating temperature (approximately
30 minutes of operation).
Note
HP
C
VOLTS
AMPS
DENSITY
A
A
HP
= Corrected Horsepower
= Actual Volts
= Actual Amperage
= Actual Air Density
A
VOLTSA × AMPSA × DENSITY
=
C
VOLTSN × AMPSN × DENSITYA
VOLTS
AMPS
HP
N
DENSITY
D
× HP
N
= Nameplate Volts
N
= Nameplate Amperage
N
= Nameplate Horsepower
= Design Air Density
D
Measurements taken on motors operating with Variable Frequency Drive controls may read up to 15% high from errors in
measuring the approximated sine wave. Instruments capable of
measuring a squared off wave form accurately should be used
for measuring power in this situation.
Do not exceed 30 sec/hour total motor starting time as motor
may overheat.
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7401 WEST 129 STREET | OVERLAND PARK, KANSAS 66213 UNITED STATES | 913 664 7400 | spxcooling@spx.com | spxcooling.com
In the interest of technological progress, all products are subject to design and/or material change without notice.
©2008 SPX Cooling Technologies, Inc. | Printed in USA
Manual 00-1352
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