LTI Axial Fan Series User manual

Axial Fan Series
O&M Manual

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1) Axial fan (Adjustable pitch type) (Appendix 1)
1.1) Disassembly of the motor and impeller
a) Dismantle the taper lock bush of the impeller as in Appendix A
b) Remove complete impeller
c) Replace impeller where necessary
d) Dismantle mounting screws of the motor from the motor base bracket
e) Replace motor where necessary
1.2) Assembly of the motor and impeller
a) Place the motor on the motor base and adjust till it is sitting in the center
b) Tighten the motor to the base properly
c) Put on the impeller and insert in the taper lock bush as in Appendix A
explanations
d) Adjust the impeller properly so that the impeller is not touching the casing
e) Make sure that tip clearance is correct if impeller is changed
f) Check that running ampere is same as original to ensure that angle is
correct

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Appendix 1
Terminal Box
Casing
Motor Support
Bracket
Motor Base
Impeller
Mounting Feets
4 x Motor
Securing Bolts to
Base

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1.3 Adjustment of Angle for Axial Adjustable Impeller
1) After dismantling the impeller,
place them on a flat surface.
2) Use a digital or analogue
protractor and make sure the hub
level is zero.
Bolts and nuts holding the
blade to the hub
3) Now, by placing the protractor on the
edge of the blade, the angle of the blade
can be recorded.
4) In case, we need to adjust the angle of
the blade, loosen all the bolts and nuts
holding the blade to the hub.
5) Using a mallet, tap the leading edge
(thicker side) of the blade to the angle
required.
6) Use the same method to adjust all the
blade angle.
7) Make sure that all angle are +/- 0.5
degree tolerance.
8) Balance the impeller and fix the
impeller back to the motor.
9) Make sure that there is no abnormal
vibration and ampere of the motor does
not exceed the full load ampere of the
motor.
Analogue Protractor
with leveling guage

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2. Dismantling of Taper Lock Bush
Appendix A
Jacking holes for removing bush
Locking screws
Removal of taper lock bush for MUB, AXV
a) Using a hexagon allen key, slacken and remove both the locking set screws
b) Use one of the set screw and screw to the jacking holes
c) Tighten screws until taper lock bush is loosened in hub and free on the shaft.
d) Remove the bush and then the impeller
Installing the taper lock bush
a) Clean, polish and grease the motor shaft before putting on the key
b) Put the impeller on the motor shaft
c) Insert the taper lock bush and tap lightly till it seat squarely on the shaft and impeller
hub
d) Align the holes of the screw and tighten the two locking screws till the hub is in firm
position

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10. Replacement of motor bearings
Figure 1
Remove fan cover screws
Remove fan cover
Figure 2
Loosen cooling fan clamping screw
Figure 3
Use a big screw driver to jack out the
coolin
g
fan
Figure 4
Remove the cooling fan

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Figure 5
Unscrew the nut of the 4 studs
holdin
g
the motor cove
r
Figure 6
Remove all 4 studs
Figure 7
Tap the end motor cover lightly
Figure 8
Remove both the front and end cover
completely

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Figure 9
Remove the stator and use a bearing
puller to remove the bearing
Figure 10
The bearing is dismantled completely
by jacking the screw on the puller
Figure 11
Replace a new bearing
Use a proper tool to that fit the inner
race of the bearing
Figure 12
Use a mallet and tap the bearing in till it
seat fully

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Maintenance Manual
Fault troubleshooting

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Common Faults and Answers
1. What to do if fan running current is higher than specified
a) Check electrical
--Make sure supply voltage are as accordance to what is specified in the
name plate
--Make sure all electrical phases have constant supply for 3 phase motor
--Make sure all electrical terminals are tightened
--Make sure capacitor is correct and functioning for single phase motor
--Make sure resistance of motor winding is constant [measure (U1,U2),
(V1,V2), (W1,W2)] for 3 phase motor
--Make sure all connection are as per our electrical diagram given
c) Check for fan vibration
--Check that fan is running smoothly and not shaken vigorously
--Check that fan blade is not rubbing against the casing
d) Make sure inlet or outlet air passage is not blocked
2) What to do if fan cannot run
a) Check that there is incoming electrical supply to the motor
If no supply voltage across the motor
--Check the MCB, overload, thermistor is not open circuit
--Electrical panel circuit is functioning properly
b) Check that termination is correct at the motor
c) Check that capacitor is correct and is in working condition for single
phase motor
d) Check that fan impeller is not stuck
e) Check that motor windings is OK as mentioned above

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3) What to do if fan has abnormal normal noise and vibration
a) Stop fan immediately
b) Check that fan rotation is correct
c) Check that fan blades are not touching casing or inlet cone
d) Check that no foreign materials are stuck at the fan blades
e) Check that fan blades are not broken
f) Check that all fasteners are tightly secured
g) Check that fan is isolated completely
h) Check that inlet and outlet air passage is not blocked
If non of the above,
Fan balancing is required
Motor bearing may be faulty
Fan may be running in unstable stage