TCF MPLFN Instruction manual

©2014 – 2023 Twin City Fan Companies, Ltd.
Contents
Introduction.................................................................................... 1
Shipping and Receiving .................................................................. 1
Handling ......................................................................................... 2
Short Term Storage......................................................................... 2
Long Term Storage.......................................................................... 2
Foundations and Supporting Structures ........................................2
Fan Installation ............................................................................... 3
Assembly of Fans............................................................................ 3
Electrical Wiring of Fans.................................................................4
Fan Operation – Safety................................................................... 4
Operation Checklist ........................................................................ 4
Maintenance of Fans...................................................................... 5
General Motor Maintenance.....................................................5
Impeller and Shaft Maintenance...............................................5
Structural Maintenance.............................................................5
Troubleshooting Guidelines ........................................................... 5
Troubleshooting Performance Problems
Air Capacity Problems ............................................................... 5
Noise Problems ......................................................................... 5
Vibration Problems.................................................................... 5
Motor Problems ........................................................................ 6
Limitation of Warranties and Claims..............................................6
Introduction
The purpose of this manual is to provide instructions that complement
good general practices when installing or operating fans manufactured
by Twin City Fan & Blower. It is the responsibility of the purchaser to
provide qualified personnel experienced in the installation, operation
and maintenance of air moving equipment.
Instructions given in the body of this manual are general in nature and
apply to a variety of models manufactured by Twin City Fan & Blower.
Most units can be installed and maintained with the instructions given.
Additional product and engineering information is available at www.tcf.
com.
Special applications may require additional information. These
instructions are supplied in the form of attached appendices. Use the
instructions in the appendix if the directions in this manual differ from
instructions in the appendix.
As always, follow good safety practices when installing, maintaining and
operating your air moving equipment. A variety of safety devices are
available. It is the user’s responsibility to determine adequate safety
measures and to obtain the required safety equipment.
Shipping 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.
Figure 1. Lifting Lug Locations
DETAIL
SCALE 1 : 2
NOTE: When lifting, the straps/
chains should be at a minimum
angle of 45°
Throughout this manual, there are a number of HAZARD WARNINGS that must be read and adhered to in order to prevent possible
personal injury and/or damage to equipment. Two signal words "WARNING" and "CAUTION" are used to indicate the severity of a hazard
and are preceded by the safety alert symbol.
WARNING
Used when serious injury or death MAY result from misuse or failure to follow specific instructions.
CAUTION
Used when minor or moderate injury or product / equipment damage MAY result from misuse or failure to follow specific instructions.
NOTICE
Indicates information considered important, but not hazard-related.
It is the responsibility of all personnel involved in installation, operation and maintenance to fully understand the
Warning and Caution procedures by which hazards are to be avoided.
Twin City Fan
IM-495
April 2023
Modular Plenum Fans
(MPLFN, MPLFS, MPLQN, MPLQS)
INSTALLATION, OPERATION & MAINTENANCE MANUAL

Twin City Fan & Blower Installation and Maintenance Manual: IM-495
Handling
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.
Units shipped completely assembled may be lifted with slings and
spreader bars. Use well-padded chains, cables or nylon straps. On
most units, lifting lugs are provided for attaching chains (see Figure
1 on page 1). Lift the fan in a fashion that protects the fan and fan
coating from damage. Never lift a fan by the inlet or discharge flange,
shafting or drives, impeller, motor or motor base, or in any other
manner that may bend or distort parts.
Partial or disassembled units require special handling. All parts
should be handled in a fashion that protects the coatings and parts
from damage. Components should be handled such that forces are
not concentrated and bending or distortion cannot occur. Housing
should be lifted using straps and spreaders. Do not distort housing
or side plates when lifting.
Short Term Storage
If fan installation is to be delayed, store the unit in a protected area.
Protect the fan and motor bearings from moisture and vibration (or
shock loading).
Long Term Storage
Prior to Storage – Motor bearings are to be greased at the time
of going into extended storage per the motor manufacturer’s
specifications.
Storage Procedure – Fans should be stored indoors whenever
possible where control over temperature, shock and dust is
reasonably maintained. If units are to be stored outside in the
elements, they should be covered with a water-resistant material.
Stored equipment should be stored on a clean, dry floor or blocked
up off the ground on blocks to prevent unit from setting in any
water or directly on the ground. If shock or vibration will be present
during storage, the unit may need to be placed on some type of
vibration dampening material to aid in preventing brinelling of the
bearing surfaces.
Periodic Check – On a monthly interval, the equipment should be
checked to ensure that it has remained in an acceptable stored
condition. After verifying the fan is disconnected from the electrical
supply, the fan impeller should be rotated several times by hand
while adding enough grease to replenish the bearing surfaces with
fresh grease and to maintain a full bearing cavity. Grease used
must be compatible with that already supplied in the motor and
fan bearings. The fan impeller should be left at approximately 180
degrees from that of the previous month to prevent the shaft and
impeller from taking a set in one position. Storage records should
be maintained to indicate the above requirements have been
followed. Consult the motor manufacturer for proper storage,
space heater connection and lubrication if the unit was supplied
with one.
Start-Up – When the unit is removed from storage, all bearing
grease should be purged and replenished with fresh grease as per
the lubrication decal. The motor resistance should be measured to
verify it is still at a satisfactory level compared to the value recorded
prior to storage.
Foundations and Supporting
Structures
Floor mounted fans should be installed on a flat, level surface with
sufficient structure support. Support shall be suitable for static and
dynamic loads and foundation frequencies be separated at least
20% from the rotational speed/speed ranges.
If the fans are mounted in a structure, the support should be placed
under the enclosure inlet and outlet edges as a minimum. The
fan mounting surfaces or beams must be flat and level. Structural
resonance should be at least 20% from the fan operating speed,
when considering the weight of all fans and accessories.
Any ducting and/or dampers with sleeves should have independent
support; do not use the fan for support. Isolating the fan from
ductwork with flex connections eliminates transmission of vibration.
1. Sufficient structure must be provided to support weight of fan
assembly.
2. Sufficient restraint must be provided to resist the pressure force
against the fans. Typically fans are assembled in an application
in a modular fashion with multiple fans working in parallel. The
cumulative thrust force must be restrained to prevent the fan
assemblies from leaning or tipping forward. The force acting on
the fan assemblies is calculated as shown below.
Thrust force (lbf) = H x W x N x Ps
27.68
Where
Ps= Maximum operating static pressure (in. w.g.)
W = Width of each individual fan (in.)
H = Height of each individual fan (in.)
N = Quantity of fans in system
27.68 = conversion factor for in. w.g. to PSI
Example
Parallel fan system employing nine (9) – Size 182 fans in a 3 x 3
configuration. (3 fans high x 3 fans wide)
System pressure is 5 inches of water column.
Outside dimension of fan housing = approx. 38 in. by 38 in.
Thrust force (lbf) = H x W x N x Ps
27.68
Thrust force (lbf) = 38 x 38 x 9 x 5 = 2348 (lbf)
27.68
Maintain handling equipment to avoid serious personal injury.
CAUTION
The thrust force is distributed evenly across the front surface of
the parallel fan system.
NOTICE

Twin City Fan & Blower Installation and Maintenance Manual: IM-495 3
3. Recommend attachments to the sides and top of the parallel fan
system incorporating some form of spring support, i.e. rubber
snubbers/isolators or springs. Such devices should be attached
to prevent significant point loading on an individual fan. They
should be located on the side of the parallel fan system at the
top corner and along the top every 2 fans or less.
a. When the fans are rigidly mounted to the base, an assumption
can be made that half of the thrust load will be supported at
the base, and the supports added at the top of the fan need
to carry a minimum of one half of the thrust load.
b. When the fans are supported on an isolation base or
isolators, it will be necessary to add thrust restraints around
the periphery of the fan assembly to support the entire thrust
load. Flex connections are required when using isolators or
isolation base.
c. Attachments to the fan can be made utilizing the factory
mounting holes. Recommend that the gage of the materials
be checked for tear out strength in thrust applications.
If necessary utilize multiple mounting hole locations to
distribute the load.
Fan Installation – Factory Assembled
Units
Follow proper handling instructions given earlier.
1. Move the fan to the final mounting position.
2. Remove skid, crates and packing materials carefully.
3. If supplied, place vibration pads or isolation base on mounting
bolts. Line up holes in fan base with bolts.
4. Place fan on mounting structure. Carefully level unit using shims
as required at all mounting hole locations. Bolt down the unit.
Assembly of Fans
1. Fans must be securely bolted to a base either directly through
the factory mounting holes or with a properly designed clip.
Final bolting of each individual row of fans to the support
structure or base should be done after the individual fans are
bolted together as a row.
2. The bolts to be snugged up on vertical sections for the first row.
Once all fasteners are in place, the bolts shall be tightened to torque
values in table. See Table 1.
3. The bolts holding the fan to the supporting structure can now be
torqued.
4. The second row and succeeding rows can be installed using the
same assembly steps as the first row.
5. Sealing around the perimeter should be accomplished using a
flexible material.
Figure 2.
Table 1. Torque Values MPLFN/MPLFS/MPLQN/MPLQS Fasteners
Size Net Type Torque Values
( lbs)
3/8 – 16 UNC Nylock 16 – 17
3/8-16 x 0.75
Screws & Nuts
front an
d
back flanges
3/8-16 x 0.75
Screws & Nuts
axial flanges
where accessable
A thin gasket or caulk may be used to prevent undesired air
leakage and noise.
NOTICE

Twin City Fan & Blower Installation and Maintenance Manual: IM-495
Electrical Wiring of Fans
The customer is required to investigate and install equipment
in compliance with all local electrical and safety codes for the
equipment location. Twin City Fan & Blower requires all power
cabling be located away from the rotating impeller and fastened
to the inside of the fan housing. Wiring must be routed away from
the motor to reduce potential contact with hot or greasy surfaces.
When a fan is supplied with an outlet damper, wiring the electrical
supply to the motor requires routing the supply through the damper
housing frame. Knockouts of various sizes are provided in the damper
housing frame to accommodate cable connectors or raceway.
Fan Operation - Safety
For general safety practices for air moving equipment, see AMCA
Catalog 410.
Twin City Fan & Blower has many safety accessories available.
These safety devices include (but are not limited to) inlet and
discharge screens. The use, abuse or non-use of safety devices is
the responsibility of the purchaser.
Facility-related safety conditions include fan accessibility and
location. How easily can non-service 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-off” by the service person and the key to be retained by
this person to prevent accidental power of the fan while service is
in process.
Operation Check List
Check fan mechanism components:
□ Systemconnectionsareproperlymadeandtightened.
□ Bearingsareproperlylubricated.
□ Impeller,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/impelleroverlap.(SeeFigure4.)
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? (See Figure 5.)
□ Correctanyproblemsthat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.
□ Setscrewsattachingimpellerhubtoshaft.
□ Nutsoninletfunnel.
□ Nutsandboltsholdingmotor.
□ Nutsholdinghousingframetobaseandbasetoground.
□ Boltsintaper-lockbushings.
□ Greaselineconnections.
After one week of operation, check all nuts, bolts and set screws
and tighten if necessary.
A
DIA
B
Figure 4. Impeller-Funnel Overlap
Size A B Size A B
1 22 12.75 0.130 2 45/ 2 45 C25.51 0.50
15 015.62 0.172 270 / 270C 28.11 0.55
165 17.18 0.203 300 / 300C 31.23 0.61
18 2 /18 2C 19.00 0.38 330/330C 34.36 0.67
200
/ 200C 20.82 0.41 365/365C 38.00 0.75
222/222C 23.16 0.45
MPLFN/MPLFS/MPLQN/MPLQS
R
o
t
a
t
i
o
n
MPLFN, MPLFS,
MPLQN & MPLQS
Wheels
Figure 5. Proper Impeller Rotation
Verify that proper safety precautions have been followed.
Electrical power must be locked off.
WARNING

Twin City Fan & Blower Installation and Maintenance Manual: IM-495 5
Maintenance of Fans
This section contains general maintenance instructions for your
Twin City Fan & Blower unit. For specific information about
maintenance of components, particularly for special application
fans, see the attached documents.
General Motor Maintenance
The three basic rules of motor maintenance are keep the motor
clean, dry and properly lubricated.
Keeping motors and windings clean is important because dirt and
dust serve as thermal insulators. Heat normally dissipated by the
motor is trapped causing overheating and/or premature failure.
Blow dust and dirt out of windings and off the motor periodically.
Use low pressure (50 psig) airstream so that winding damage does
not occur. Keep the area surrounding the motor open so the air can
circulate through the motor cooling fan. Follow normal maintenance
schedule given to the right.
Motors should be kept dry to avoid electrical short circuits. Motors
kept in storage for long periods of time can have moisture condense
on the windings. Be certain the motor is dry before using.
Some smaller motors are lubricated for life. Motor bearing
lubrication, if required, must follow a rigorous schedule. 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 50 hp, every 3 years; and motors 50 to 150 hp, yearly. For
motors in a dusty or dirty environment or running 24 hours a
day, divide the service interval by 2. If the environment is very
dirty or high temperatures exist, divide the service interval by 4.
Lubrication requirements are normally attached to the motor. Do
not overlubricate.
Impeller and Shaft Maintenance
Periodically inspect the shaft and impeller for dirt buildup, corrosion
and signs of excess stress or fatigue. Clean the components and,
when appropriate, apply new coatings. (Any addition of coatings or
weld can create an imbalance.) Check the balance of the assembly.
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 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 ensure the structural
integrity of the foundation.
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. Impeller 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.
2. Bearing failure. Check bearings (lubrication).
3. Supply voltage high or inconsistent supply frequency. Adjustable
frequency controllers can generate motor noise.
4. Objects that 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.
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, impeller).
5. Broken, loose or missing set screws.
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.
All fans manufactured by Twin City Fan & Blower are factory
balanced prior to shipment. Installation variables, 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.
NOTICE

Twin City Fan & Blower Installation and Maintenance Manual: IM-495
Motor Problems:
1. Incorrect wiring.
2. Speed of fan too high.
3. Parts improperly installed - binding.
4. Bearings improperly lubricated.
5. WR2capability of motor too low for application.
6. Protection devices may be improperly sized.
Motor Lubrication – The major cause of motor 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 and the bearings are regreasable, the motor bearings should
immediately be filled with grease while rotating the fan 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 motor bearings are
lithium base. Use the greases shown in the motor information. Do
not mix the bases without completely purging out the initial grease.
Initially, follow the lubrication instruction in the motor information.
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.
Limitation of Warranties and Claims
Seller warrants to the original purchaser that the goods sold
hereunder shall be free from defects in workmanship and material
under normal use and service (except in those cases where the
materials are supplied by the buyer) for a period of one year from
the date of original installation or eighteen (18) months from the
date of shipment, whichever occurs first. The liability of seller under
this warranty is limited to replacing, repairing or issuing credit (at
cost, F.O.B. factory and at seller’s discretion) for any part or parts
that are returned by buyer during such period provided that:
a. seller is notified in writing within ten (10) days following
discovery of such defects by buyer, or within ten (10) days
after such defects should reasonably have been discovered,
whichever is less;
b. the defective unit is returned to seller, transportation charges
prepaid by buyer.
c. payment in full has been received by seller or said products;
and
d. seller’s examination of such unit shall disclose to its satisfaction
that such defects have not been caused by misuse, neglect,
improper installation, repair, alteration, act of God or accident.
e. seller cannot guarantee sound pressure levels or dBA.
No warranty made hereunder shall extend to any seller product
whose serial number is altered, effaced or removed. Seller
makes no warranty, express or implied, with respect to motors,
switches, controls or other components of seller’s product, where
such components are warranted separately by their respective
manufacturers. THIS WARRANTY IS EXPRESSLY IN LIEU OF ALL
OTHER WARRANTIES, EXPRESS OR IMPLIED, WHETHER STATUTORY
OR OTHERWISE, INCLUDING ANY IMPLIED WARRANTY OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. In no
event shall seller be liable to buyer for indirect, incidental collateral
or consequential damages of any kind. (BUYER’S FAILURE TO PAY
THE FULL AMOUNT DUE WITHIN SIXTY (60) DAYS OF DATE OF
INVOICE SHALL OPERATE TO RELEASE SELLER FROM ANY AND ALL
LIABILITY OR OBLIGATION ARISING PURSUANT TO ANY WARRANTY,
EXPRESS OR IMPLIED, WHETHER STATUTORY OR OTHERWISE,
INCLUDING ANY IMPLIED WARRANTY OR MERCHANTABILITY OR
FITNESS FOR A PARTICULAR PURPOSE, MADE IN CONNECTION
WITH ANY CONTRACT FORMED HEREUNDER. BUYER AGREES THAT
SUCH FAILURE TO PAY SHALL CONSTITUTE A VOLUNTARY WAIVER
OF ANY AND ALL SUCH WARRANTIES ARISING PURSUANT TO SUCH
CONTACT.)

Twin City Fan & Blower Installation and Maintenance Manual: IM-495 7
Twin City Fan

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