Bulletin 74-September -01-10
CORPORATION
SERVING THE NEEDS OF MODERN INDUSTRY
INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
Introduction
This bulletin contains the proper installation, operation
and maintenance procedures for the standard AXTC Inline
Centrifugal Fiberglass Fan, to ensure safe and trouble-free
fan operation.
The M.K. Plastics catalog on the above corrosion resistant
FRP fan, provides additional information describing the
equipment, fan performance, available accessories, and
specications.
For additional safety information, refer to AMCA publication
410-96, Safety Practices for Users and Installers of Industrial
and Commercial Fans.
For Information on special fan application requirements,
contact M.K. Plastics corporate ofce at (514) 871-9999.
AXTC
Inline Tubular Centrifugal Fiberglass Fan
Handling
Fans are to be hoisted and moved by the lifting lugs or
mounting brackets provided on the fan (see Figure 1).
Location of lugs & brackets varies by fan size and application.
Fans can also be hoisted with slings placed around the fan
housing. When a single hoist is used, a “spreader” will keep
the sling from slipping on the housing. Large units may have
lifting lugs or holes which should be used only to stabilize the
unit while using a sling to support the weight.
Chain or wire slings should be well-padded where they
contact the fan as not to cause damage to the berglass
surface. Fans should never be lifted by the shaft, fan
housing, motor, belt guard, damper, weather hood, inlet &
outlet anges or any other accessories.
Receiving and Inspection
All M.K. Plastics fans are carefully inspected before leaving
the factory. 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.
Mishandled units can void the warranty provisions. If units
are damaged in transit, it is the responsibility of the receiver
to make all claims against the carrier. M.K. Plastics is not
responsible for damages incurred during shipment.
WARNING
This unit has rotating parts. Safety precautions
should be exercised at all times during installation,
operation, and maintenance.
ALWAYS disconnect power prior to working on fan.
M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 1
Figure 1.
Lifting Using the Mounting Brackets
Storage
If the unit cannot be installed and operated immediately,
precautions need to be taken to prevent deterioration of the
unit during storage. The user assumes responsibility of the
fan and accessories while in storage. M.K. Plastics will not be
responsible for damage during storage.
Store in a dry, protected area being sure fan shaft, bearings
and impeller are protected against dust and corrosion. If it
is necessary to store outdoors or within a building under
construction, special care must be taken to prevent moisture,
dirt or dust accumulation. Coat the shaft with grease or rust
preventative compound. Cover and seal bearings to prevent
entrance of contaminants. Impeller should be rotated at least
once a month to circulate the grease in bearings. If stored
outdoors, cover completely with a tarp or heavy plastic wrap.
Electrical connections and leads must be protected from
moisture. Block impeller to prevent natural rotation. Do not
allow material of any kind to be piled on top or inside of fan.
Exhaust & Supply Roof Installation
Roof Curb
Structural Steel Support
Continuous/Stitch Weld
Roof Curb
Concrete Structure
Ø
1
2
" Anchor Bolts at 6" centers,
(4" max' spacing from curb corner)
Roof Curb
Structural Steel Support
Continuous/Stitch Weld
AXTC fans that are roof mounted with curbs should be
securely attached to roof structure such as structural steel,
concrete or wooden decks. Roof structure supports per
structural engineer, in accordance with load requirements
and applicable building codes.
Concrete Roof Deck
Roof Curb
1
Ø
" Anchor Bolts at 6" centers,
2
(4" max' spacing from curb corner)
Roof Curb Attachment
Curb Cap
Lag Bolts
Roof Curb
Figure 2.
Roof Mounted AXTC Fan
Concrete Structure
Structural Steel Support
Roof Curb
Continuous/Stitch Weld
Structural Steel Support
Wood Roof Deck
Roof Curb
1
Ø
" Lag Bolts at 6" centers,
2
(to be determined by structural engineer)
1. Lift the fan onto the roof curb. Make sure the fan securely
sits on the curb and level.
2. It is recommended to secure the fan in place on the curb
with lag bolts spaced at minimum 6” centers.
3. Pre-drill pilot holes through the side of the fan curb cap
and into the curb wood nailer strip.
4. To prevent any possible water penetration, ll the entire
pilot hole or bolt thread with exterior grade, waterproof
silicone caulking.
5. Secure into place through the pilot holes with stainless
steel, lag bolts. Some caulking will be forced out of the
hole to form a better barrier around the xing.
Vibration Isolators
To prevent vibration and noise from being transferred to
the building, vibration isolators are recommended. Isolators
should be located between the fan system and the support
structure. M.K. Plastics supplies three main types of isolators
for FRP fans:
• Floor Mounted Spring Isolators (oor mounting)
• Floor Mounted Rubber-In-Shear Isolators (oor
mounting)
• Hanging Spring Isolators (ceiling mounting)
Refer to the M.K. Plastics submittal for isolator installation
and adjustment instructions. In applications where seismic
isolators are required, contact M.K. Plastics directly for
further details.
Wooden Structure
M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 2
Spring Isolator Rubber-In-Shear
Figure 3.
Vibration Isolators (Typical)
Hanging Spring
Ducted Installations
Min.
2 x Dia.
Min.
2 x Dia.
Min.
2 x Dia.
Min.
2 x Dia.
Efcient fan performance relies on the proper installation
of inlet and discharge ducts. Installations with poor inlet or
discharge congurations may result in reduced performance.
Make sure the following recommendations are followed.
Non-Ducted Inlet
If the AXTC has an open inlet (no duct work) that is too close
to a wall or bulkhead, this may cause performance problems.
The fan needs to have a minimum of two effective wheel
diameters away from inlet to the wall.
Duct Connections
To reduce possible vibration transmission through the
ductwork, M.K. Plastics recommends the use of exible
connectors instead of a rigid duct connection (e.g. angeto-ange connection). Companion anges are standard
accessories for exible connection.
Inlet Flexible
Connector
Outlet Flexible
Connector
Min.
2 x Dia.
Figure 4. - Open Inlet
Free Discharge
If possible, avoid a free discharge into a plenum which could
result in lost efciency because the effect of discharge static
regain is not allowed.
Figure 5.
Free Discharge
Inlet Duct Turns
Installation of a duct turn or elbow too close to the fan inlet
reduces fan performance. To achieve full fan performance,
there should be at least two effective wheel diameters
between duct turns or elbows and the fan inlet.
Good Poor
Min.
2 x Dia.
Turning Vanes
Figure 6 - Inlet Ducting
Discharge Duct Turns
Where possible, allow minimum two duct diameters between
duct turns or elbows and fan outlet.
Inlet Duct
Inlet Companion
Flange
Outlet Duct
Outlet Companion
Flange
Figure 8. - Inlet/Outlet Flexible Duct Connection
Wheel-Inlet Overlap
Efcient performance is achieved by having the correct wheel
to inlet overlap and uniform radial gap. This should always be
veried before initial start-up and if possible after the fan has
been in operation for 24 hours.
The overlap is adjusted by loosening the wheel hub on the
shaft and moving the wheel to the correct position - refer to
Table 1. for values. A uniform radial gap (between the edge of
wheel inlet and edge of inlet cone) is achieved by loosening
the bolts on the inlet cone and centering it on the wheel. In
both cases, a trim balance maybe required.
Overlap
[inches]
Table 1.
Overlap
Figure 9.
Wheel/Inlet Overlap
Size
1825 0.75
2225 0.94
2450 1.00
2700 1.06
3000 1.31
3300 1.38
3650 1.50
4025 1.63
4450 1.81
4900 2.00
5425 2.13
6000 2.38
Wheel/Inlet Overlap
Good Poor
Min.
2 x Dia.
Figure 7 - Discharge Ducting
M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 3
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 ne 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.
Belt tension is determined by the sound the belts make
when the fan is rst started. Belts will produce a loud squeal
which dissipates after the fan is operating at full capacity. If
the belt tension is too tight or too loose, lost efciency and
possible damage can occur. The proper tension for operating
a V-belt is the lowest tension at which the belts will not slip
at peak load conditions. For initial tensioning, the proper belt
deection half-way between pulley centers is 1/60” for each
inch of belt span.
Deflection [inch]
Belt Span [inch]
Figure 10. - Belt Tension
Refer to the following procedure for belt tensioning -
1. Loosen motor plate adjustment bolts and move motor
plate in order that the belts can easily slip into the
grooves on the pulleys. 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 deection of approximately 1/60”
per inch of center distance should be obtained by rmly
pressing the belt. Refer to Figure 10.
3. Lock the motor plate adjustment nuts in place.
4. Ensure pulleys are properly aligned.
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. Never use belt
dressing on any belts.
Drive Alignment
Pulley alignment is adjusted by loosening the motor pulley
setscrew and by moving the motor pulley on the motor shaft.
Fig. 11 illustrates correct and incorrect pulley alignment.
A recommended method of inspecting
the pulley alignment is shown in Figure
12. With the shorter leg of a carpenter’s
square or other straight edge lying
along the case of the motor, adjust
the position of the motor pulley (or the
motor) until the longer leg of the square
is parallel to the belt.
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
ve 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.
Figure 12.
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.
Wheel Rotation
Test the fan to ensure the rotation of the wheel is the same
as indicated by the arrow marked Rotation. One of the most
frequently encountered problems with centrifugal fans is
motors which are wired to run in the wrong direction. This is
especially true with 3-phase installations where the motor will
run in either direction, depending on how it has been wired.
To reverse rotation of a 3-phase motor, interchange any two
of the three electrical leads. Single phase motors can be
reversed by changing internal connections as described on
the motor label or wiring diagram. Figure 13. shows the wheel
rotation as viewed from the fan inlet.
Correct Incorrect
Incorrect Incorrect
Figure 11. - Pulley Alignment
M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 4
Figure 13. - Wheel Rotation
Relubrication Schedule [Months]
Speed [rpm] 500 1000 1500 2000 2500 3000
Size
1825 6 6 5 3 3 3
2225 6 6 5 3 3 -
2450 6 6 5 3 - -
2700 6 6 5 3 - -
3000 6 5 4 - - -
3300 6 5 4 - - -
3650 6 5 - - - -
4025 5 4 - - - -
4450 5 4 - - - -
4900 5 4 - - - -
5425 5 4 - - - -
6000 4 3 - - - -
Table 2. - Relubrication Schedule [Months]
Fan Bearing Lubrication
Proper lubrication of the fan drive bearings helps assure
maximum bearing life. All AXTC bearings are lubricated
through a grease tting on the outer housing and should
be lubricated by the schedule, Table 2. 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.
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.
All bearings are lled 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 sufcient amount of grease to purge the seals. Rotate
bearings by hand during relubrication.
Fan Bearing Replacement
Replacement of bearings requires disassembly of internal
components. For this procedure access must be available
to both the inlet/outlet ends and the lower fan casing half,
although it possible on smaller fans for bearing replacement
without access to the fan inlet. The following procedure
assumes belts have already been loosened and removed.
(Belts are removed by adjusting the motor pivot plate).
AXCT fans have split-pillow block type bearings on horizontal
applications and the addition of a ange-type bearing on
vertical applications. Replacement is similar for both. Refer
to the fan parts list on Page 8.
1. Unbolt and remove the lower casing section, belt and
shaft guards.
2. Remove the inlet cone by removing the bolts around the
perimeter.
3. Remove the wheel hub cover, loosen the wheel bushing
and slide the wheel off the shaft. Note, on smaller fans
it may be possible to leave the wheel on the shaft and
remove the wheel/shaft/bearing assembly as one piece
out of the fan housing.
4. Note the location of the fan sheave on the end of the
shaft and remove the sheave.
5. Note the distance from the bearing to the end of the
shaft.
6. Unbolt both sets of bearings from the support plates and
remove the shaft/bearing assembly out the fan casing.
7. Reinstall components in reverse order of removal and
reference the Overlap, Radial Gap and Alignment
sections on Page 3. and 4.
8. Test run the fan and retighten all hardware, trim balance
if necessary.
Changing Shaft Speed
All belt driven fans with motors up to and including 5 HP
are equipped with variable pitch pulleys. To change the fan
speed, perform the following:
1. Loosen setscrew on driver (motor) pulley and remove
key, if equipped.
2. If the pulley has multiple grooves, all must be adjusted
to the same width.
3. After adjustment, inspect for proper belt tension.
4. To reduce speed, open the pulley in order that the belt
rides deeper in the groove (smaller pitch diameter).
5. To increase speed, close the pulley so that the belt rides
higher in the groove (larger pitch diameters). Make sure
the maximum fan RPM and motor HP is not reached.
M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 5
Size
1825 NSK,SNN,1-7/16 389 in-lbs 1/2-13UNC 517 in-lbs 542 in-lbs
2225 NSK,SNN,1-7/16 389 in-lbs 1/2-13UNC 517 in-lbs 542 in-lbs
2450 NSK,SNN,1-11/16 389 in-lbs 1/2-13UNC 517 in-lbs 542 in-lbs
2700 NSK,SNN,1-11/16 389 in-lbs 1/2-13UNC 517 in-lbs 542 in-lbs
3000 NSK,SNN,2-3/16 673 in-lbs 5/8-11UNC 1110 in-lbs 1160 in-lbs
3300 NSK,SNN,2-3/16 673 in-lbs 5/8-11UNC 1110 in-lbs 1160 in-lbs
3650 NSK,SNN,2-3/16 673 in-lbs 5/8-11UNC 1110 in-lbs 1160 in-lbs
4025 NSK,SNN,2-7/16 673 in-lbs 5/8-11UNC 1110 in-lbs 1160 in-lbs
4450 NSK,SNN,2-15/16 1682 in-lbs 3/4-10UNC 1530 in-lbs 1582 in-lbs
4900 NSK,SNN,2-15/16 1682 in-lbs 3/4-10UNC 1530 in-lbs 1582 in-lbs
5425 NSK,SNN,2-15/16 1682 in-lbs 3/4-10UNC 1530 in-lbs 1582 in-lbs
6000 NSK,SNN,3 1682 in-lbs 3/4-10UNC 1530 in-lbs 1582 in-lbs
Pillow Block
Bearing
Bearing Cap
Bolt Torque
Mounting
Bolt
304 SS Bolt
Torque
316 SS Bolt
Torque
Table 3. - Fan Bearing Torque
Tapered
Bushing
P1-P3 5/16-18UNC 80 in-lbs
Q1-Q3 3/8-16UNC 143 in-lbs
Q1-Q3 1/4-20UNC 45.6 in-lbs
JA No.10-24UNC 60 in-lbs
QT 1/4-20UNC 108 in-lbs
SH-SDS-SD 1/4-20UNC 108 in-lbs
SK 5/16-18UNC 180 in-lbs
SF 3/8-16UNC 360 in-lbs
E 1/2-13UNC 720 in-lbs
F 9/16-12UNC 1320 in-lbs
J 5/8-11UNC 1620 in-lbs
M 3/4-10UNC 2700 in-lbs
N 7/8-9UNC 3600 in-lbs
P 1-8UNC 5400 in-lbs
W 1-1/8-7UNC 7200 in-lbs
S 1-1/4-7UNC 9000 in-lbs
Cap Screw Torque
MSK
Bushing
Cap Screw Torque
H 1/4 x 3/4 95 in-lbs
P 5/16 x1 192 in-lbs
Q 3/8 x 1-1/4 348 in-lbs
R 3/8 x 1-3/4 348 in-lbs
S 1/2 x 2-1/4 840 in-lbs
U 5/8 x 2-3/4 1680 in-lbs
W 3/4 x 3 3000 in-lbs
Table 4. - Bushing and Pulley Torque
Operational Checklist
Final Installation
F Inspect fasteners and setscrews, particularly fan
mounting and bearing fasteners, and tighten according
to the recommended torque shown in Tables 3 & 4.
F Inspect for correct voltage with voltmeter.
F Ensure all accessories are installed.
Pre-Start Checks
F Shut off all primary and secondary power sources.
F Ensure fasteners and setscrews are tightened.
F Inspect belt tension and pulley alignment.
F Inspect motor wiring.
F Ensure belt touches only the pulleys.
F Ensure fan and ductwork are clean and free of debris.
F Inspect wheel-to-inlet clearance.
F Close and secure all access doors.
F Restore power to the fan.
Start Up
Turn the fan on. In variable speed units, set the fan to its
lowest speed and inspect for the following:
F Direction of rotation.
F Excessive vibration.
F Unusual noise.
F Bearing noise.
F Improper belt alignment or tension (listen for squeal-ing).
F Improper motor amperage or voltage.
If a problem is discovered, immediately shut the fan off. Lock
out all electrical power and check for the cause of the trouble.
See Troubleshooting.
Inspection
Inspection of the fan should be conducted at the rst
30 minute, 8 hour and 24 hour intervals of satisfactory
operation. During the inspections, stop the fan and inspect.
F 30 Minute Interval: Inspect bolts, setscrews, and motor
mounting bolts. Adjust and tighten as necessary.
F 8 Hour Interval: Inspect belt alignment and tension.
Adjust and tighten as necessary.
F 24 Hour Interval: Inspect belt tension. Adjust and tighten
as necessary.
General Fan Maintenance
WARNING
Disconnect and secure to the ‘Off’ position all electrical power to the fan prior to inspection and servicing.
Failure to comply with this safety precaution could
result in serious injury or death.
Once the unit has been put into operation, a routine
maintenance schedule should be set up to accomplish the
following:
1. Lubrication of bearings and motor.
2. Wheel, housing, bolts and set screws on the entire fan
should be checked for tightness.
3. Any dirt accumulation on the wheel or in the housing
should be removed to prevent unbalance and possible
damage.
4. Isolation bases should be checked for freedom of
movement and the bolts for tightness. Springs should be
checked for breaks and fatigue. Rubber isolators should
be checked for deterioration.
5. Inspect fan impeller and housing looking for fatigue,
corrosion or wear.
6. Check V-belt drives on a regular basis for wear, tension,
alignment and dirt accumulation.
M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 6
Troubleshooting
Excessive Noise or Vibration
• Damaged wheel.
• Wheel rubbing inlet; adjust wheel or inlet cone.
• Verify wheel balance, rebalance if necessary.
• Belts misaligned.
• Belts too loose; worn or oily belts.
• Loose fasteners.
• Speed too high.
• Incorrect direction of rotation. Make sure the fan rotates in same direction as the arrows on the motor or belt drive
assembly.
• Bearing collars or hardware loose.
• Bearings need lubrication or replacement.
• Debris in impeller; clean all dirt off wheel, check wheel balance and rebalance if necessary.
• Fan surge.
• Check alignment of shaft and motor drives.
Low Volume or Pressure
• Incorrect direction of rotation. Make sure the fan rotates in same direction as the arrows on the motor or belt drive
assembly.
• Poor fan inlet or outlet conditions. There should be a straight clear duct at the inlet or outlet.
• Improper wheel alignment.
• Check duct system, see Page 3. For recommendations.
Motor Problems (Overheating)
• Motor improperly wired.
• Incorrect direction of rotation. Make sure the fan rotates in same direction as the arrows on the motor or belt drive
assembly.
• High horsepower; resize the ductwork. Check proper operation of face and bypass dampers. Check lters and
access doors.
• Cooling air diverted or blocked.
• Improper inlet clearance.
• Incorrect fan speed.
• Incorrect voltage.
Bearing Problems (Overheating)
• Improper bearing lubrication; check for excessive or insufcient grease in bearings.
• Excessive belt tension.
• Check for bent shaft.
• Align bearings.
M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 7
AXTC - Parts List (Horizontal)
11
13
12
10
8
14
7
6
3
2
1
4
5
9
21
13
17
18
19
20
16
15
Item No. Item Description
1 Hub Cover
2 Bushing
3 Inlet Cone
4 Impeller
5 Hub Seal
6 Shaft
7 Pillow-Block Bearing
8 Adjusting Rod
9 Motor Support Bracket
10 Motor Support
11 Motor Base
12 Motor
13 Drive Pulley
14 Drive Belts
15 Motor Cover
16 Belt Guard
17 Fan Casing (Top)
18 Access Door
19 Shaft Guard
20 Fan Casing (Bottom)
21 Mounting Brackets
M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 8
AXTC - Parts List (Vertical)
18
16
15
17
13
14
12
11
10
9
8
6
7
5
4
3
Item No. Item Description
2
1 Inlet Cone
2 Hub Cover
1
3 Bushing
4 Impeller
5 Hub Seal
6 Shaft
7 Pillow-Block Bearing
8 Flange Bearing
9 Fan Casing (Top)
10 Motor Support Bracket
11 Motor Base & Support
12 Motor
13 Motor Cover
14 Drive Pulley
15 Drive Belts
16 Belt Guard
17 Shaft Guard
18 Fan Casing (Bottom)
M.K. Plastics Corp. Montréal, Québec www.mkplastics.com Page. 9
AXTC - Parts List (Roof Mounted)
1
2
6
3
1
5
4
6
5
3
4
Roof Mounted Supply Roof Mounted Exhaust
Item No. Item Description
1 Buttery Damper (Exhaust) / Weatherhood (Supply)
2 Damper Counterweight
3 Motor Cover
4 Curb Mounting Cap
5 Access Door
6 AXTC Fan Housing
Bulletin 74-September -01-10
CORPORATION
SERVING THE NEEDS OF MODERN INDUSTRY
4955 de Courtrai Ave., Montréal, Québec, H3W 1A6 ● TEL: (514) 871-9999
Trimex Building, Route 11, Mooers, N.Y., 12958 ● TEL: (888) 278-9988
FAX: (514) 871-1753
Email: mkfans@mkplastics.com
Loading...