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Centrifugal Fume Exhaust Fans
INSTALLATION, OPERATION & MAINTENANCE MANUAL
IM-390
August 2014
INTRODUCTION
This manual has been prepared to guide the users of BAIFE and BCIFE Fume Exhaust Fans in the proper installation,
operation and maintenance procedures to insure maximum equipment life with trouble-free operation.
CONTENTS
Inspection and Receiving ...........................................................................................................................................................2
Handling and Rigging .................................................................................................................................................................2
Storage .........................................................................................................................................................................................2
Installation
• Pre-Installation Checklist .................................................................................................................................................... 2
• Foundations and Supporting Structures ...........................................................................................................................3
• Roof Curb Installation .........................................................................................................................................................3
• Mixing Box Assembly Installation ......................................................................................................................................3
• Fan and Windband Installation .......................................................................................................................................... 3
• Drain Connections ...............................................................................................................................................................4
• Damper and Actuator Installation ...................................................................................................................................... 4
Operation Checklist .....................................................................................................................................................................5
Maintenance
• Fan .......................................................................................................................................................................................5
• Motor ....................................................................................................................................................................................5
• Bearing .................................................................................................................................................................................5
• Drive ..................................................................................................................................................................................... 6
• Wheel and Shaft .................................................................................................................................................................6
• Structural .............................................................................................................................................................................6
• Fan Operation - Safety ......................................................................................................................................................6
Troubleshooting ...........................................................................................................................................................................6
Caution:
Fan systems include rotating components and electrical devices. Proper care must be taken during installation
and maintenance of all fan system components to protect personnel. This includes, but is not limited to the use
of protective enclosures, guards, locking devices to stop rotating parts, and electrical disconnect lock-outs. Refer
to applicable local codes to ensure compliance for all protective devices.
Fans create a suction at the inlet. Care should be taken around a the inlet of the fan, whether it is in operation
or not. Make sure the inlet area is clear prior to energizing the system. This includes all personnel and loose,
foreign objects.
©2012 Twin City Fan Companies, Ltd.
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INSPECTION AND RECEIVING
All Twin City Fan & Blower products are carefully constructed and inspected before shipment to insure the highest standards of quality and performance. Compare all
components with the bill of lading or packing list to verify
that the proper unit was received. Check each unit for any
damage that may have occurred in transit. Any damage
should be reported immediately to the carrier and the
necessary damage report filed.
UNIT STORAGE
If fan installation is to be delayed, store the unit in an
environmentally stable and protected area. During storage,
the fan should not be subjected to vibration from external
sources or bearing damage may occur. The unit should be
reasonably protected from any accidental impacts. Cover
the fan to protect coatings and to prevent any foreign
material or moisture from entering the inlet or discharge.
Take care to protect the motor, drives and bearings.
HANDLING AND RIGGING
Handling of all air moving equipment should be conducted
by trained personnel and be consistent with safe handling
practices. Verify the lift capacity and operating condition of
handling equipment. Maintain handling equipment to avoid
serious personal injury.
Units shipped may be lifted with slings and spreader bars.
Use well-padded chains, cables or nylon straps (see Figure
1). On most units, lifting lugs are fashioned to protect the
fan and fan housing from damage. Never lift a fan by the
inlet or discharge flange, shafting or drives, wheel, motor
or motor base, or in any other manner that may bend or
distort parts.
Mixing plenum boxes configured for multiple fans mounted
on a common unit are modular in design and may be
broken down into smaller segments for ease of installation
and handling.
Figure 1. Lifting Locations
Extended storage requires monthly inspections. Check for
corrosion or damage to the unit and for debris within the
fan.
Bearings tend to take on moisture if the atmosphere in
which they are stored is not at a constant temperature. To
avoid corrosion, it is necessary to keep the bearings full
of grease and to rotate them periodically. Even when full
of grease, bearings will take on moisture, so it is necessary
to purge the bearings with new grease to expel moisture
every thirty days. It is recommended that the bearings be
purged with grease while being rotated by hand. Do not
use high pressure greasers as they may ruin the bearing
seals.
The drives and belts should be removed if the fan is to
be stored for a prolonged period. The drives should be
labeled for service and stored in a dry place. Belts should
be removed, coiled without kinks, placed in a heavy carton, and stored in a dry, well-ventilated place. To prevent
belt deterioration storage conditions should not exceed
85°F and 70% humidity. If belts show signs of deterioration, they should be replaced prior to startup.
Motors should be stored in a clean, dry, vibration-free
location. The packaging should be opened up enough to
allow air circulation around the motor. The winding temperature should be kept slightly above that of the surroundings to prevent condensation. This can be accomplished by energizing the internal heaters, if the motor is
so equipped, or by using space heaters. If it is impossible
to heat the windings, the motor should be wrapped
tightly with a waterproof material which also encloses several bags of desiccant. Replace the desiccant regularly to
prevent moisture problems. The motor rotor should also be
rotated regularly (monthly) to assure the bearing parts are
well greased.
Start-Up – When the unit is removed from storage, all fan
bearing grease should be purged and replenished with
fresh grease as per the lubrication decal. The motor should
be measured to verify that the resistance is still at a satisfactory level compared to the value recorded prior to
storage.
INSTALLATION
Pre-Installation Checklist
Prior to fully assembling and installing, inspect the fan and
ancillary components to ensure it is in working order.
• Check all external and internal hardware on the fan,
wheel, bearings, drive motor base and accessories for
tightness.
• Rotate the fan wheel by hand and assure no parts are
rubbing. Adjust components prior to installation as adjustments are easier while lower to grad.
• Check proper wheel clearances to be sure near tolerance. The wheel will need to be realigned after installation, therefore, clearances should be near tolerance.
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Twin City Fan IM-390
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Foundations and Supporting Structures
The best means of floor mounting a fan is on a welldesigned, flat, level concrete foundation. The foundation
should have a mass of at least three times that of the
supported assembly. Rigid foundation stiffness must be
between 1x10
size and speed. The foundation should extend 6” beyond
the outer dimensions of the fan and driver; however, it
should be no more than twice the area required for the
equipment. If it is made larger, the mass should be
increased accordingly to resist rocking modes of vibration. J or T type anchor bolts of sufficient size should
be used and should be tied into the reinforcing bar for
the foundation. After the concrete is poured, a pipe
sleeve with a diameter of 2 to 2
diameter should be provided around the anchor bolt for
final adjustment. The mounting surface of the foundation
should be smooth for good shim contact. When deciding
the thickness of the foundation, approximately 1 to 1
height should be allowed for shimming, grouting, leveling,
washers, nuts, etc.
Fans mounted on a sub-floor or mezzanine must have
adequate stiffness or be mounted on an inertia base
with springs properly selected.
If a structural steel base or platform is to be used, the
structure must be designed for the weight of the fan,
live loads imposed by rotation of the rotor and driver,
and any external live loads. The structure should be
designed to ensure that no natural frequency will occur
within 30% of the fan speed. This is especially true if
the structure supports more than one fan.
Any ducting should have independent support. Do not
use the fan to support ducting as the housing or pedestal may become distorted. The fan frame can be
designed to carry some external loads. Consult the factory if this is a concern. Isolating the fan from ductwork
with flex connections eliminates transmission of vibration.
Fans handling hot gases require expansion joints at both
the inlet and discharge to prevent excessive loads
caused by thermal growth.
Roof Curb Installation
Caution: Roof curbs should be square and level to ensure
safe fan installation and proper sealing of gas stream to
the fan.
Roof curbs shall be installed and fully attached to structural support (by others) which is typically steel or concrete
using 1/2" diameter bolts w/ 1-3/8" washers (by others).
Figure 2. Bolted Installation
For attachment to structural steel the curb can be continuously welded or stitch welded using 3/8" x 6" welds
with a maximum of 3" spacing between welds. Welds
should be evenly spaced along curb side and corners.
6
lbs./in. to 4x106 lbs./in. depending upon
1
⁄2 times the anchor bolt
1
⁄2"
Figure 3. Welded Installation
Mixing Plenum Box Assembly and Installation
The modular plenum mixing boxes are designed to allow
for easy installation and future expandability. Single mixing
plenum boxes are fully assembled (less any dampers) to
expedite installation. Depending on the size, multi-unit mixing boxes may or may not be assembled. When installing
the mixing box(es), it is important to follow the guidelines
for lifting and rigging on page 2.
When a single-unit mixing plenum box is installed, prepare
the roof curb or mounting structure. Lay gasket material
on the top edge of the roof curb. Lift mixing box onto
curb and square (level) mixing box.
Depending on the air intake (side or bottom), the mixing
box must be oriented to allow for direct duct connection
into the mixing plenum box. Match drill roof curb to mixing plenum box. Attach mixing plenum box to curb using
1/2” diameter bolts with 1 3/8” washers (by others).
For multi-unit configurations, some assembly may be
required. There are at least two different assemblies in a
multi-unit configuration. There is the mixing plenum box
assembly and the mixing box spacer. There will be one
less spacer than the quantity of mixing plenum boxes.
To assemble, space the mixing boxes a distance apart that
is slightly more than the width of the spacer section. Utilize
a gasket between the mixing box and the spacer section
to provide a tight seal.
Install 316 stainless steel bolts to attach the spacer and
the mixing box. Repeat as necessary for each section.
When the multi-unit mixing plenum box is assembled, rig
the mixing box system with spreader bar to avoid any
damage.
Install mixing plenum box assembly onto a prepared (gasket material on mating surface) roof curb or mounting
structure. Lay Square (level) mixing box. Install lag bolts
into the mixing plenum box to roof curb as indicated.
Fan and Windband Installation
• Follow proper handling instructions as provided earlier.
• Identify each fan and component and match the
equipment up with the supplied customer drawing(s).
• Move the fan to the final mounting location.
• Remove skid, crates and packing materials carefully.
• If vibration isolation is to be used, place isolation
base on mounting bolts. Line up holes in fan base
with bolts.
• Fans shipped as a single unit shall be broken down
into several parts. Install each item individually in the
following order:
1. Fan onto vibration or rigid base
Stack extension, if in the scope of supply
2. Windband
Note: When installing the components, lifting lugs shall be
utilized for safe installation. Lifting lugs are designed for the
weight of the component they are welded to and should not
be used to lift assemblies.
Twin City Fan IM-390
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Y
X
P
P
FF
GAP
Fan Housing Installation
1. Place the fan on mounting structure. Carefully level
the unit (checking the level on the shaft) on the foundation and shim as necessary using stainless steel
shims on both sides of each anchor belt. Verify that
the fan inlet is properly aligned and level with the
outlet on the mixing box if provided.
2. Install 316 stainless steel hardware (provided) in all
mounting holes. Use a commercially available antiseizing compound formulated for 316 stainless steel
to hardware.
3. Check the alignment of the bearings. Shim or reposition the bearings if necessary.
4. Check face alignment of sheaves on belt driven fans.
Check tension of belts to see if it is sufficient. Sheaves
on belt driven fans are often provided with taperlock
bushings. When tightening bushing bolts, proceed in
a progressive manner to avoid cocking the tapered
surfaces between the bushing and the sheave.
5. Check alignment of factory mounted couplings, as
they are subject to misalignment during shipment and
installation. Realign to within 0.002" offset and parallel. Allow for thermal growth of the motor by setting
the motor 0.001" low for each inch of shaft up to
0.005". NOTE: Most couplings need lubrication.
6. Check the tightness of the wheel on the shaft.
Check the tightness of foundation bolts, motor bolts, sheaves, and bearings. Make sure there
is no rubbing or binding and that the wheelinlet cone clearances and overlap are correct.
Flexible Couplings
These instructions are general for the installation of several types of flexible couplings and should not be used
as a substitute for more specific manufacturer’s instructions. The coupling manufacturer’s installation data is
available and will give specific dimensions for alignment
limits, lubricants, etc. Refer to Item 5 fan for coupling
alignment requirements.
Before preparing to mount the coupling, make sure that
all bearings, inlet vanes, shaft seals, or other components have been installed on the shaft.
When mounting and keying the coupling halves to the
shaft, follow supplied instructions for heating and shrink
fitting. Set the coupling halves for the normal gap specified by the manufacturer. Coupling gap is illustrated in
figure 4.
The two types of misalignment are illustrated above.
Typically angular alignment is checked with feeler gauges between the hub faces. When angular alignment has
been adjusted to manufacturer’s specification by shimming, if necessary, parallel alignment can be checked
with a straightedge and feeler gauges on the hub halves’
O.D. When shimming has brought parallel alignment
within specification, angular alignment and gap should
again be checked, and adjustments made if necessary.
A dial indicator or laser alignment may be used to more
accurately take the measurements described above.
Figure 4.
ANGULAR PARALLEL GAP AND
MISALIGNMENT MISALIGNMENT END FLOAT
X-Y = ANGULAR MISALIGNMENT
P = PARALLEL OFFSET (MISALIGNMENT)
F = END FLOAT
Thoroughly clean the coupling halves after completion of
alignment. Reassemble the coupling and tighten bolts,
washers and locknuts. Lubricate per manufacturer’s recommendations.
Stack Extension Installation
1. Place supplied gasket around the perimeter of the
fan outlet.
2. Lower the stack extension onto the fan housing aligning the bolt holes on the two components. Allow for
gasket to compress naturally prior to securing fan
housing to the adjacent component.
3. Install 316 stainless steel hardware (provided) in all
mounting holes. Use a commercially available antiseizing compound formulated for 316 stainless steel
to hardware.
Windband Installation
1. Using the windband lifting lugs, raise the windband
above the outlet of the fan assembly. Align the support
brackets with the fan assembly discharge
2. Using caution not to swing the windband, insert the
316 stainless steel mounting hardware (provided) coated with anti-seize compound to join the two components.
Drain Connection/Installation
Each section of the plenum mixing box as well as the
fan housing contains a 3/4" NPT drain pipe for connecting to drainage system to ensure safe routing of any
liquid that may form in the system. Due to the potential
of hazardous chemical contamination, proper disposal of
liquids is required (by customer).
Note:
• A minimum of 1" of water must be placed in trap prior to
start-up to create proper “lock” of system pressure.
• Drain should periodically be cleaned out for proper operation.
Damper and Actuator Installation
Access to the Isolation Damper is obtained through
opening the slide out door on the side of the plenum.
Remove bolts from face of slide out door and remove
damper/door assembly for inspection and maintenance.
Figure 5. Drain
Special adjustments may need to be made for couplings
used with some equipment. As an example, when used
with motors of over 300 HP, couplings may require provisions for limiting end float. Larger drivers may grow
in operation (due to heat expansion) requiring the driver
side to be set slightly low when not operating. Refer to
specific instruction manuals or assembly drawings.
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The 2-Position spring return actuator is attached to the
damper shaft through the slide out door in a Nema 4
enclosure and can be removed with the damper/door assembly. Wiring is completed through knockouts in Nema
4 enclosure around the actuator.
Access to Bypass Damper and Modulating Actuator for
removal is obtained by removing the weatherhood covering the damper. Damper is attached to plenum face with
standard zip screws. An inspection door is available on
the side of the weather cover for standard inspection and
maintenance of the damper. Wiring for the modulating
actuator is fed through the knockouts in the weatherhood.
Figure 6. BAIFE and BCIFE Wheel Placement
BC-SW, BC-DW, BCS, BAF SWSI & DWDI Wheel Placement
Size
122 135 150 165 182 200 222 245 270
A
12.25 13.50 15.00 16.50 18.25 20.00 22.25 24.50 27.00
B
0.32 0.34 0.38 0.44 0.56 0.63 0.69 0.75 0.88
Size
300 330 365 402 445 490 542 600 660
A
30.00 33.00 36.50 40.25 44.50 49.00 54.25 60.00 66.00
B
0.97 1.06 0.94 1.03 1.13 1.25 1.38 1.56 1.69
A
DIA
OPERATION CHECKLIST
Verify that proper safety precautions have been followed:
□ Electrical power must be locked off
Check fan mechanism components:
□ System connections are properly made and tightened.
□ Bearings are properly lubricated.
□ Wheel, drives and fan surfaces are clean and free of
debris.
□ Rotate the impeller by hand to verify it has not
shifted in transit.
□ Check fan/wheel overlap. (See Figure 6.)
□ Drives on correct shafts (not reversed).
□ Check position of guards to prevent rubbing.
Check fan electrical components:
□ Motor is wired for proper supply voltage.
□ Motor was properly sized for power and rotational
inertia of rotating assembly.
□ Motor is properly grounded.
□ All leads are properly insulated.
Trial “bump”:
□ Turn on power just long enough to start assembly
rotating.
□ Check rotation for agreement with rotation arrow.
□ Does the assembly make any unusual noise?
□ Check drive alignment and tension. Does this meet
with drive manufacturer’s recommendations?
□ Correct any problems which may have been found.
(Follow safety guidelines - shut power off.) Perform
checklist again until unit is operating properly.
□ Run unit up to speed.
Verify fastener tightness. These may have loosened
during shipment or installation.
□ Setscrews attaching wheel hub to shaft.
□ Setscrews in drive sheaves or coupling.
□ Nuts on inlet funnel.
□ Nuts and bolts holding motor.
□ Nuts holding housing frame to base and base to
ground.
□ Nuts on accessories including shaft seal, access
doors and pie-splits.
□ Bolts in taper-lock bushings.
□ Grease line connections.
B
FAN MAINTENANCE
Periodically inspect the shaft and wheel for dirt buildup,
corrosion, and signs of excess stress or fatigue. Clean
the components. If the wheel is removed for any reason,
make sure that it is securely attached to the shaft before
restarting the fan.
All structural components or devices used to support
or attach the fan to a structure should be checked at
regular intervals. Vibration isolators, bolts, foundations,
etc., are all subject to failure from corrosion, erosion,
and other causes. Improper mounting can lead to poor
operation characteristics or fan fatigue and failure. Check
metallic components for corrosion, cracks, or other signs
of stress. Concrete should be checked to insure the
structural integrity of the foundation. See curb installation section for detail on proper mounting procedures.
MOTOR MAINTENANCE
The three basic rules of motor maintenance are:
1. Keep the motor clean.
2. Keep the motor dry.
3. Keep the motor properly lubricated.
Blow dust off periodically (with low pressure air) to prevent motor from overheating. Some smaller motors are
lubricated for life. Lubrication requirements are normally
attached to the motor. Use the motor manufacturer’s
recommendations for relubrication. If this information is
not available, the following schedule may be used. Motors less than 10 HP running about eight hours a day in
a clean environment should be lubricated once every five
years; motors 15 to 40 HP, every three years. For motors
in dusty or dirty environments or running 24 hours a day:
divide the service interval by 4. Do not over lubricate.
BEARING MAINTENANCE
Proper lubrication of the fan drive bearings helps assure
maximum bearing life. All fans are equipped with decals
indicating relubrication intervals for normal operating conditions. However, every installation is different and the
frequency of relubrication should be adjusted accordingly.
On high moisture applications, the lubrication frequency
may need to be doubled or tripled to adequately protect the bearings. Double the relubrication frequency on
fans with vertical shafts. Observation of the conditions
of the grease expelled from the bearings at the time of
relubrication is the best guide as to whether regreasing
intervals and amount of grease added should be altered.
After one week of operation, check all nuts, bolts and
setscrews and tighten if necessary.
Twin City Fan IM-390
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Greases are made with different bases. There are synthetic base greases, lithium base, sodium base, etc.
Avoid mixing greases with different bases. They could be
incompatible and result in rapid deterioration or breakdown of the grease. The lubrication sticker identifies a
list of acceptable lubricants. All bearings are filled with
a lithium-based grease before leaving the factory. When
the fans are started, the bearings may discharge excess
grease through the seals for a short period of time. Do
not replace the initial discharge because leakage will
cease when the excess grease has worked out. Sometimes the bearings have a tendency to run hotter during
this period. There is no reason for alarm unless it lasts
over 48 hours or gets very hot (over 200°F). When relubricating, use a sufficient amount of grease to purge
the seals. Rotate bearings by hand during relubrication.
DRIVE MAINTENANCE AND INSTALLATION
V-belt drives need periodic inspection, retensioning, and
occasional belt replacement. When inspecting drives, look
for dirt buildup, burrs or obstructions that can cause premature belt or drive replacement. If burrs are found, use
fine emery cloth or a stone to remove them. Be careful
that dust does not enter the bearings. Check sheaves for
wear. Excessive slippage of belts on sheaves can cause
wear and vibration. Replace worn sheaves with new
ones. Carefully align sheaves to avoid premature sheave
failure. Inspect the belts for wear. If fraying or other wear
is observed to be mostly on one side of the belts, the
drives may be misaligned. Reinstall the drives according
to the following instructions:
1. Slip (do not pound) proper sheave onto corresponding shaft. CAUTION: Placing fan sheave on motor can
overspeed wheel and cause structural failure.
2. Align sheaves with straightedge extended along
sheaves, just making contact in two places on outside
perimeters of both sheaves.
3. Tighten sheave bolts (or setscrews if appropriate).
Table 1 can be used to determine the amount of
torque required.
4. Install a matched set of belts. Adjust the motor position to obtain slack, install, and tighten belts. Using a
pry bar will damage belts.
5. Tighten belts to proper belt tension. Ideal tension is just
enough so that the belts do not slip under peak load.
When using drive tensioning data supplied by V-belt
drive manufacturers, new belts can be tensioned to a
value 50% greater than for normal operation. This will
reduce retensioning requirements after break-in. Recheck sheave alignment after tensioning.
6. After initial installation of belts, recheck belt tension
again after a few days. (New belts require a break-in
period of operation.)
7. When replacing belts, replace the entire set. After initial
replacement and tensioning, recheck belt tension after
a few days. (New belts require a break-in period of
operation.) Never use belt dressing on any belts.
8. Fans that have motors and drives mounted at the factory are trim balanced prior to shipment. This is not
possible on units that are shipped without motors and
drives. The addition of drive components in the field
can create unbalance forces. Twin City Fan & Blower
recommends final balancing of the unit after the drive
components are installed. Failure to do so may void
the warranty.
WHEEL AND SHAFT MAINTENANCE
Periodically inspect the shaft and wheel for dirt buildup,
corrosion, and signs of excess stress or fatigue. Clean
the components. If the wheel is removed for any reason,
make sure that it is securely attached to the shaft before
restarting the fan.
STRUCTURAL MAINTENANCE
All structural components or devices used to support or
attach the fan to a structure should be checked at
regular intervals. Vibration isolators, bolts, foundations,
etc., are all subject to failure from corrosion, erosion,
and other causes. Improper mounting can lead to poor
operation characteristics or fan fatigue and failure. Check
metallic components for corrosion, cracks, or other signs
of stress. Concrete should be checked to insure the
structural integrity of the foundation.
FAN OPERATION—SAFETY
For general safety practices for air moving equipment,
see AMCA Bulletin 410. AMCA Bulletin 410 and other
AMCA publications can be purchased from AMCA’s
website at http://www.amca.org/store. Twin City Fan &
Blower offers many safety accessories. These safety
devices include (but are not limited to) belt guards,
shaft guards, inlet and discharge screens. The use and
suitability of safety devices is the responsibility of the
purchaser.
Facility related safety conditions include fans’ accessibility and location. How easily can nonservice personnel access the unit? Is the fan in a hazardous duty
environment? Was the unit ordered for this duty? Other
concerns must also be addressed. All fans should be
powered through switches which are easily accessible to
service personnel from the fan. Every switch should have
the ability to be “locked out” by the service person and
the key to be retained by this person to prevent accidental powering of the fan while service is in process.
TROUBLESHOOTING GUIDELINES
Use current safety practices when investigating fan or
system performance problems. General safe practices and
performance troubleshooting guidelines can be found in
AMCA Publications 410 and 202, respectively. Fan application and field measurement procedures can be found in
AMCA Publications 201 and 203.
TROUBLESHOOTING PERFORMANCE
PROBLEMS
The lists below indicate possible areas to check when
air or sound values do not match expectations. Most fan
problems can be pinpointed to one of these common
causes.
Air Capacity Problems:
1. Resistance of system not at design rating. If resistance
is lower than expected, both airflow and horsepower
may be up. If resistance is higher than anticipated, air
volume will be down.
2. Fan speed is not at design speed.
3. Air density not at design values. Also check air performance measurement techniques/procedures.
4. Devices for air modulation are closed or plugged. Also
check filters.
5. Wheel mounted improperly or is rotating in reverse.
6. Parts of system or fan have been damaged or need
cleaning.
Noise Problems:
1. Air performance is incorrect and fan is not at design
point of operation. Fan forced to operate in an unstable
flow region.
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Twin City Fan IM-390
Page 7
2. Bearing failure. Check bearings (lubrication).
3. Supply voltage high or inconsistent supply frequency.
Adjustable frequency controllers can generate motor
noise.
4. Objects which are installed in a high velocity airstream
can generate noise. This includes flow sensors, turning
vanes, etc.
5. Poor fan inlet conditions.
6. Acoustics or sound measurement procedure incorrect.
shaft turning within the bearing, and (2) crowned bearing
supports. Loosen one bolt and measure the clearance
between the pillow block and the support. Add shim to
compensate.
Spherical Roller Bearings with Set Screw Lock – The selfaligning characteristic of these bearings are inherent in the
spherical roller design. The closer that these bearings are
to perfect alignment, the cooler they will operate.
Vibration Problems:
1. Misalignment of drive components.
2. Poor foundations or mounting structure (resonances).
3. Foreign material attached to rotating components.
4. Damaged rotating components (bearings, shaft, fan,
wheel, sheaves).
5. Broken, loose or missing setscrews.
6. Loose bolts.
7. Vibration transmitted by another source.
8. Water accumulating in airfoil blades.
9. Fan is operating in stall or unstable flow region.
NOTE: All fans manufactured by Twin City Fan & Blower
are factory balanced prior to shipment. Handling and
movement of the fan during shipment may cause the rotating assembly to shift. Balance should be checked once
the fan is installed. If a final trim balance is required, it
is the end user’s responsibility to bring the fan back to
factory specifications. Final trim balancing is not the responsibility of Twin City Fan & Blower. Refer to Figure 7
for vibration guidelines.
Motor Problems:
1. Incorrect wiring.
2. Speed of fan too high.
3. Parts improperly installed - binding.
4. Bearings improperly lubricated.
5. WR2 capability of motor too low for application.
6. Protection devices may be improperly sized.
Figure 7. Vibration Guidelines, unfiltered
Condition
Start-up
Alarm
Shutdown
Value shown are peak velocity, mm/s (inches/s), Filter out.
Table taken from ANSI/AMCA Standard 204-05, Table 6.3.
Fan
Application
Category
BV-3 6.4 (0.25) 8.8 (0.35)
BV-4 4.1 (0.16) 6.4 (0.25)
BV-3 10.2 (0.40) 16.5 (0.65)
BV-4 6.4 (0.25) 10.2 (0.40)
BV-3 12.7 (0.50) 17.8 (0.70)
BV-4 10.2 (0.40) 15.2 (0.60)
Rigidly Mounted
mm/s (in./s)
Flexibly Mounted
mm/s (in./s)
Drive Problems:
1. Belts improperly tensioned.
2. Drive alignment is poor.
Bearing Problems:
Generally speaking, Twin City Fan & Blower uses three
types of bearings:
1. Ball bearing with set screw lock.
2. Spherical roller bearings with set screw lock.
3. Spherical roller bearings with adapter lock/taper lock
feature to attach them to the shaft.
Ball bearings – These are self-aligning bearings and should
present no alignment problems with one exception: i.e., on
Sealmaster bearings there is a pin beneath the grease fitting which prevents the bearings outer race from rotating.
Should this pin jam, the bearing loses its alignment feature.
Common failure causes are (1) set screws loosening and
Common failure causes are the same as with ball bearings, mainly set screws loosening and crowned bearing
supports.
Spherical Roller Bearings with Adapter Lock – Again, the
self-aligning feature is inherent in the spherical design.
Good alignment results in a cooler operating bearing. The
faster the bearing operates the more critical this becomes.
A common cause of failure is improper installation practice.
Removing too much clearance from the bearing can result
in preloading the bearing, resulting in premature failure;
and removing not enough can result in the shaft rotating
within the bearing. Properly tightened, this method of attaching a bearing to a shaft is second only to a press fit.
Crowned bearing supports can also preload these bearings
and should be checked by loosening one side of the bearing and checking for clearance.
Lubrication – The major cause of bearing failure is contamination of grease, insufficient grease, or incompatibility
of grease. If a fan is to be stored for any length of time
at the job site, the bearings immediately should be filled
with grease while rotating the shaft and then the bearings
should be regreased and rotated monthly. This will prevent moisture, which condenses within the bearing, from
corroding the raceways. Most greases used on fan pillow
blocks are lithium base. Use the greases shown on the
bearing decal. Do not mix the bases without completely
purging out the initial grease.
Initially, follow the lubrication instruction on the side of the
fan. The frequency of lubrication should be adjusted depending on the condition of the old grease being purged.
This is the responsibility of the user. If the grease is dirty,
the lubrication frequency should be more often.
a. Noise – If a bearing is increasing in noise intensity
and/or vibration, it will probably result in failure.
b. Temperature – If a bearing temperature begins to
gradually rise, it will generally result in failure. A bearing can operate up to 200 degrees and operate satisfactorily if the temperature remains constant and the
bearing receives adequate lubrication. Remember that
a roller bearing under the same load and speed will
be somewhat more noisy and run warmer than a ball
bearing. This is normal.
Rough handling and/or dropping a fan can result in brinelling the bearing. This appears as a clicking noise at
first, then gradually worsens until failure.
When replacing a bearing, always align the bearings first,
then bolt the pillow blocks to their support, rotate the
shaft, fasten the bearings to it. If the bearing is fastened
to the shaft first, tightening the pillow block bolts may
bind the shaft and preload the bearings.
Twin City Fan IM-390
7
Page 8
Figure 8. Safety & Lubrication Instructions for Fans with Ball Bearings
WARNING
1. This equipment must not be operated without proper guarding of
all moving parts. While performing maintenance be sure remote
power switches are locked off. See installation manual for recommended safety practices.
2. Before starting: Check all setscrews for tightness and rotate wheel
by hand to make sure it has not moved in transit.
Relubrication Schedule (Months)*
Speed (RPM)
Shaft DIA
500 1000 1500 2000 2500 3000 3500 4000 4500
1
⁄2" thru 111⁄16"
(13 – 45)
15
1
⁄16" thru 27⁄16"
(50 – 60)
11
2
⁄16" thru 215⁄16"
(65 – 75)
7
3
⁄16" thru 315⁄16"
(80 – 100)
Ball Bearing Pillow Blocks
6 6 5 3 3 2 2 2 1
6 5 4 2 2 1 1 1 1
5 4 3 2 1 1 1
4 3 2 1 1
* Suggested lubrication interval under ideal continuous operating conditions. Relubricate while running, if safety permits, until some purging
occurs at seals. Adjust lubrication frequency depending on conditions
of purged grease. Use one-half of listed interval for vertical shaft applications or for 24 hour operation. Hours of operation, temperature, and
surrounding conditions will affect the relubrication frequency required.
1. Lubricate with a high quality NLGI No. 2 lithium-base grease having rust inhibitors and antioxidant additives, and a minimum oil
viscosity of 500 SUS at 100°F (38°C). Some greases having these
properties are:
Shell - Gadus S2 V100 2 Exxon - Ronex MP
Mobil - Mobilith SHC100 Mobil - Mobilith SHC220
2. Lubricate bearings prior to extended shutdown or storage and
rotate shaft monthly to aid corrosion protection.
Figure 9. Safety & Lubrication Instructions for Fans with Unit Roller
Bearings
WARNING
1. This equipment must not be operated without proper guarding of
all moving parts. While performing maintenance be sure remote
power switches are locked off. See installation manual for recommended safety practices.
2. Before starting: Check all setscrews for tightness and rotate wheel
by hand to make sure it has not moved in transit.
Relubrication Schedule (Months)*
Spherical Roller Bearing - Solid Pillow Blocks
Speed (RPM)
DIA
Shaft
500 1000 1500 2000 2500 3000 3500 4000 4500
7
1" thru 1
11
1
⁄16" thru 23⁄16"
7
2
⁄16" thru 37⁄16"
–
(60
85)
15
3
⁄16" thru 415⁄16"
–
(90
125)
⁄16"
6 4 4 2 1 1 1 1
4 2 1
3 1
1
2
⁄2 1 1⁄2 1⁄
1
⁄2 1 1⁄2 1⁄2 1⁄2 1⁄2 1⁄
1
⁄2 1 1⁄2 1⁄2 1⁄4 1⁄
4
1
⁄
2
4
2
(25 – 35)
(40 – 55)
Figure 10. Safety & Lubrication Instructions for Fans with Spherical
Roller Bearings with Split Pillow Block Housings
WARNING
1. This equipment must not be operated without proper guarding of
all moving parts. While performing maintenance be sure remote
power switches are locked off. See installation manual for recommended safety practices.
2. Before starting: Check all setscrews for tightness, and rotate wheel
by hand to make sure it has not moved in transit.
Relubrication Schedule (Months)*
Shaft DIA
7
1
⁄16" thru 115⁄16"
(35 – 50)
23⁄16" thru 213⁄16"
(55 – 70)
215⁄16" thru 315⁄16"
(75 – 100)
47⁄16" thru 415⁄16"
(110 – 135)
57⁄16" thru 615⁄16"
(140 – 180)
Spherical Roller Bearing - Split Pillow Blocks
500 750 1000 1500 2000 2500 3000 3500 4000
6 41⁄24 4 31⁄221⁄221⁄21 1 0.50 oz.
5 41⁄24 21⁄221⁄211⁄
41⁄24 31⁄221⁄211⁄211⁄
4 4 21⁄211⁄
4 21⁄211⁄
2
Speed (RPM)
2
1
1
⁄
2
⁄
2
4
2
*Suggested lubrication interval under ideal continuous operating conditions. Remove bearing cap and observe condition of used grease after
lubricating. Adjust lubrication frequency as needed. Use one-half of
listed interval for vertical shaft applications or for 24 hour operation.
Hours of operation, temperature, and surrounding conditions will affect
the relubrication frequency required. Clean and repack bearings annually. Remove old grease, pack bearing full and fill housing reservoir
o n b o t h s i d e s o f b e a r i n g s t o b o t t o m o f s h a f t .
1. Lubricate with a high quality NLGI No. 2 lithium-base grease having rust inhibitors and antioxidant additives, and a minimum oil
viscosity of 500 SUS at 100°F (38°C). Some greases having these
properties are:
Shell - Gadus S2 V100 2 Exxon - Ronex MP
Mobil - Mobilith SHC100 Mobil - Mobilith SHC220
2. Lubricate bearings prior to extended shutdown or storage and
rotate shaft monthly to aid corrosion protection.
3. Purge or remove old grease when changing lubrication brands or
types.
Static Oil Lubrication
1. Use only high quality mineral oil with a VG grade indicated on the
customer submittal drawing.
2. Static oil level should be at the center of the lower-most roller
(Do not overfill.)
3. Complete lubrication change should be made annually.
Grease
to be
added
at each
interval
1
⁄40.75 oz.
2.00 oz.
4.00 oz.
7.00 oz
*Suggested lubrication interval under ideal continuous operating conditions. Relubricate while running, if safety permits, until some purging
occurs at seals. Adjust lubrication frequency depending on conditions
of purged grease. Use one-half of listed interval for vertical shaft applications or for 24 hour operation. Hours of operation, temperature, and
surrounding conditions will affect the relubrication frequency required.
1. Lubricate with a high quality NLGI No. 2 lithium-base grease having rust inhibitors and antioxidant additives, and a minimum oil
viscosity of 500 SUS at 100°F (38°C). Some greases having these
properties are:
Shell - Gadus S2 V100 2 Exxon - Ronex MP
Mobil - Mobilith SHC100 Mobil - Mobilith SHC220
2. Lubricate bearings prior to extended shutdown or storage and
rotate shaft monthly to aid corrosion protection.
TWIN CITY FAN & BLOWER | WWW.TCF.COM
5959 Trenton Lane N | Minneapolis, MN 55442 | Phone: 763-551-7600 | Fax: 763-551-7601
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