FT KT Series User manual

Instruction Manual
Centrifugal Fan
Turbofan Type KT/KTS/KP
Note
Thank you for selecting a Atai Fan.
To ensure safety and maximum service life of the fan, please read this instruction manual thoroughly
prior to operation, inspection and maintenance. Keep this manual carefully at hand so that it can be
consulted anytime when operating, inspecting or maintaining the fan.
For contractors who carry out equipment work:
Please be sure to deliver this manual to user(s) who will carry out operation, inspection and
maintenance of the fan.
Atai Fuji Motor Co., Ltd.

I
Limited warranties
1. In the event of failure or breakage under proper use of the product during the warranty period,
equipment supplied by Atai Fuji Motor. will be repaired or replaced free of charge within the scope of
the relevant part, provided that such failure or breakage is attributable to inadequacy of the design
or workmanship of the equipment.
2. The warranty mentioned in the above clause shall be only the mechanical warranty of the defective
part, and shall not cover any expenses or other damage arising from the failure or breakage.
3. In the event of the following failures and breakage, the costs of the repairs shall be for the account
of the user.
(1) Failures and breakage attributable to equipment that was not delivered by Atai Fuji Motor.
(2) Failures and breakage after the expiration of the warranty period
(3) Failures and breakage caused by disasters or force majeure, such as fire, acts of God or
earthquakes
(4) Failures and breakage resulting from repairs or modifications made without the consent of Atai
Fuji Motor.
(5) Failures and breakage when parts other than those designated by Atai Fuji Motor. are used
4. Atai Fuji Motor. shall not be liable for the damage caused by incorrect or reckless use of the fan.
Cost and expenses incurred for sending engineer(s) in such a case shall be borne by the user.
5. If the cause of the failure is unclear, necessary actions shall be determined through mutual
consultation.

II
Purpose of this manual
The purpose of this manual is to provide the user with detailed information necessary to properly
operate, maintain and inspect the fan.
This manual contains the following information and is intended for persons experienced in the
operation of fans, or for those who have been trained by such experienced persons. Only qualified
personnel such as electrical engineers are allowed to carry out the electrical wiring work.
Contents
Limited warranties ..................................................................................................................................... I
Purpose of this manual............................................................................................................................. II
Contents ................................................................................................................................................... II
1. Safety precautions 1
1.1 Types and meanings of warning terms......................................................................................... 1
1.2 Safety precautions........................................................................................................................ 1
1.2.1 Precautions for placement and installation ............................................................................ 1
1.2.2 Precautions for operation.......................................................................................................2
1.2.3 Precautions for maintenance and inspection ......................................................................... 2
1.3 Location of the warning labels...................................................................................................... 2
2. Configuration and overview of the fan 4
2.1 Structure and part names of the fan.............................................................................................4
2.2 Specifications and accessories of the blower............................................................................... 5
3. Placement and installation 6
3.1 Before using the fan ..................................................................................................................... 6
3.2 Precautions during transportation and storage............................................................................. 7
3.2.1 Precautions for transportation................................................................................................ 7
3.2.2 Precautions for storage.......................................................................................................... 7
3.3 Precautions for the location of installation....................................................................................7
3.4 Foundation ................................................................................................................................... 8
3.5 Installation .................................................................................................................................... 8
3.6 Precautions for connecting the ducts ........................................................................................... 9
3.7 Precautions for wiring work ........................................................................................................ 11
4. Preparation for operation 12
4.1 Points to be checked before test running ................................................................................... 12
4.1.1 Checking the electrical system ............................................................................................ 12
4.1.2 Checking the fan system ..................................................................................................... 12
4.2 Trial run ...................................................................................................................................... 13
4.2.1 Precautions at the time of starting the fan ........................................................................... 13
4.2.2 Precautions during the operation ......................................................................................... 13
4.2.3 Precautions when stopping the operation............................................................................ 14
5. Stopping the fan 14
5.1 Precautions when stopping the use............................................................................................ 14
6. Maintenance and inspection 15
6.1 Daily inspection .......................................................................................................................... 15
6.2 Periodic inspection ..................................................................................................................... 15
7. Troubleshooting 16
7.1 Troubleshooting.......................................................................................................................... 16
8. Special accessories 17
8.1 Dampers..................................................................................................................................... 17
8.2 Expansion joints ......................................................................................................................... 17
8.3 Filter ........................................................................................................................................... 17

1
1. Safety precautions
1.1 Types and meanings of warning terms
This instruction manual divides precautions into the following four categories according to the
level of hazards (or the severity of the accident).
Be sure to understand the meanings of the following terms and comply with the content
(instructions) of the instruction manual.
Safety sign Meaning
Danger
Indicates an imminently hazardous situation. Failure to observe the
procedures or instructions will result in death or serious injury.
Warning
Indicates a potentially hazardous situation. Failure to observe the
procedures or instructions may result in death or serious injury.
Caution
Indicates a potentially hazardous situation. Failure to observe the
procedures or instructions will result in minor or moderate injury or cause
damage to equipment or devices.
Note Indicates information that is in particular to be noted or emphasized.
1.2 Safety precautions
1.2.1 Precautions for placement and installation
(1) Move and place the fan considering the center of gravity and its mass.
(2) Install it according to the instruction manual.
(3) Do not install it anywhere exposed to high temperature or direct flame.
(4) Do not install it anywhere with high humidity.
(5) For the type of standard specifications, do not install the fan in machine or chemical
factories etc which may contain acids, alkalis, organic solvents, toxic gases such as paint
fumes, or corrosive gases.
(6) Install the outdoor air intake in a position far away from the exhaust vents of combustion
gas, etc.
(7) Be sure to install a ground fault interrupter to the main power.
(8) Only qualified personnel such as electrical engineers are allowed to carry out the electrical
wiring work. Before working, be sure to turn off the main power.
(9) Do not bend, pull or trap the motor connection cables or forcibly push them into the casing.
Doing so may result in electric shock.
(10) Do not expose the motor to water (for indoor types).
If it gets wet, the resulting short circuit and/or insulation degradation of the electric circuit
may damage the fan.
(11) Do not place any obstacles that may hinder ventilation or any combustibles around the
motor.
(12) For the type which provided with drain outlet, arrange its piping properly.
(13) Install a protective wire mesh etc. to the open air intake.

2
1.2.2 Precautions for operation
(1) Before starting the fan, ensure that all the relevant workers are informed of the operation
and that there are no workers in the dangerous zone.
(2) Only those who are authorized by the site manager are allowed to operate the fan.
(3) Be sure to attach the terminal box cover of the motor before turning on the power.
(4) When the fan is running, never touch any parts of the unit unless it is absolutely necessary.
(5) Do not put your fingers or other objects into the air intake or exhaust vents.
(6) Do not put your fingers or other objects into the opening of the motor. Failure to observe
this may cause an electric shock, injury, or fire.
(7) Do not place any objects around the air intake or exhaust vents of the fan.
(8) Remove any tools and other objects from the top of the fan before operation.
(9) Be sure to attach a belt guard or a shaft coupling to the fan during operation.
(10) If the gas is hot, do not touch the fan body as it can also be hot.
1.2.3 Precautions for maintenance and inspection
(1) Maintenance and inspection must be carried out only by personnel who have been trained
to handle the fan.
(2) Before starting maintenance or inspection, ensure to inform the relevant personnel of the
operation.
(3) Before starting the maintenance or inspection work, ensure to stop the fan and turn off the
main power on the operation panel.
If you carry out the maintenance or inspection work with the power on, you may suffer an
electric shock and/or get injured by unexpected activation of the fan during the work.
(4) In case dust or oil components adhere to the fan, clean the fun regularly.
Failure to observe this may cause malfunctions, damage, or accident.
(5) Consult Atai Fuji Motor. or a service company before moving, repairing, or modifying the fan.
1.3 Location of the warning labels
The figure below shows the locations to which each warning label should be affixed. If these
labels become dirty and hard to read or if they are peeled off, replace with a new one.
Warning
Follow all warnings on the labels affixed to the fan and those in the
instruction manual.

3
KT-010S/010T/020S/020T/040S/040T/100T (same positions also for heat resisting types)
KT-*075/*150/*220/*370 (The asterisks “*” are replaced by “5,” “6,” or “B.”)
ラベル２
ラベル１
銘板
Nameplate
Label 1
Label 2
Warning
Caution
Label 2
Label 1
Danger of injury
Do not put your
finger, a bar, etc.
in the machinery.
Hot surface
Hands off
Label 1
Label 2 Nameplate
(For hot gas types)
Fig-1

4
2. Configuration and overview of the fan
2.1 Structure and part names of the fan
KT-010S/010T/020S/020T/040S/040T/100T
KT-*075/*150/*220/*370
*1: It is not included in model KTS.
No. Part name
cFan casing
dImpeller
eSuction flange *1
fDischarge flange *1
gMotor

5
2.2 Specifications and accessories of the blower
If you purchased a standard product, refer to the standard specifications in the following table.
For a custom-made product with special specifications, refer to the specifications including the
external dimensions drawing.
Caution
Do not use this product under any conditions other than those
provided in the specifications. Failure to observe this may cause an
electric shock, fire, and/or product failure.
(1) Standard specifications and special specifications
KT-010S/010T/020S/020T/040S/040T/100T
Clean air
Air 0°C to 60°C
Installation location Indoor (ambient temperature: 0°C to 40°C)
Installation method Floor mount (only in the orientation where the shaft is
placed horizontally)
Type Totally enclosed type (0.1/0.2kW),
Totally enclosed fan-cooled type (0.4/1.0kW)
50Hz, single phase 100V, 3 phases 200V (1.0kW output is
only achieved at 3 phases 200V.)
Motor
Phase, voltage 60Hz, single phase 100V, 3 phases 200V (1.0kW output is
only achieved in 3 phases 200V.)
Inside······· Modified alkyd resin coating (silver color)
Standard specifications
Coating Outside ···· Polyurethane resin coating (silver color)
Outdoor type
Hot gas type (Gas at over 60°C and up to 250°C)
Structure
modifications Special orientation of discharge flange
Special
specifications
Motor modifications Different voltage
KT-*075/*150/*220/*370
Clean air
Air 0°C to 150°C (Except for motors of enhanced safety or
explosion-proof type)
Installation location Indoor (ambient temperature: 0°C to 40°C)
Installation method Floor mount (only in the orientation where the shaft is
placed horizontally)
Type Totally enclosed fan-cooled
50Hz, 3 phases, 200V
Motor
Phase, voltage 60Hz, 3 phases, 200/220V
Inside······· Heat resisting coating (silver color) *2
Standard specifications
Coating Outside ···· Heat resisting coating (silver color) *2

6
Outdoor type
Hot gas type (Gas at over 150°C and up to 250°C)
Structure
modifications Special orientation of discharge flange
Different voltage
Special
specifications
Motor modifications Enhanced-safety, pressure-resisting or explosion-proof
type, corrosion resisting type and high efficiency type
*2：As model KTS is made of stainless steel, only acid pickling is available without
coating.
(2) Standard and special accessories
Standard accessories Special accessories
Companion flange Vibration insulating base
Shaft seal Vibration insulating liner
Suction wire mesh Foundation bolt
Suction damper Expansion joint
Discharge wire mesh *3 Filter
- Silencer
- Cable gland for outdoor use *4
*3: Provided only with models KT-010S/010T/020S/020T.
*4: If the models KT-010S/010T/020S/020T/040S/040T/100T are used outdoors,
connect a cable gland for outdoor use to the terminal box of the motor, and
carry out wiring with a cable for outdoor use.
Also use a cable with suitable outer diameter to the cable gland.
(It also applies to heat-resistant products.)
3. Placement and installation
3.1 Before using the fan
When you receive the fan, check the following points first.
If there are any problems, contact the sales agent you purchased the product from.
Handle the motor according to the instruction manual of the motor.
Incorrect handling may result in an accident or failure.
(1) Check the nameplate to verify that the unit is the one you ordered.
In particular, check the information on the rated current (50Hz or 60Hz).
(2) Check if the orientation of discharge flange and direction of rotation are as ordered.
(3) All the accessories that you ordered have been delivered.
(4) No part of the product is damaged during transportation.
(5) All fastening parts including bolts and nuts are securely tightened.

7
3.2 Precautions during transportation and storage
3.2.1 Precautions for transportation
· Do not get under the lifted fan. The fan may fall onto you.
· Ask a specialist company to move and place the fan in
consideration of the center of gravity and its mass.
· Before hoisting the unit, refer to the catalogue or external
dimensions drawing etc. to confirm that the mass of the fan does
not exceed the load limit of the hoisting equipment.
· Do not hoist the entire fan using the hook on the motor or any
other parts not intended for the purpose.
(1) When hoisting the fan, wind rope or wire rope on the motor base or the fan casing.
(2) Use as long ropes and wires as possible so that the fan can be lifted at an angle of 90° or
less, which prevents the fan from being deformed/damaged by the lifting load.
3.2.2 Precautions for storage
(1) Protect the unit so that rust does not form during storage before installation, assembly or
starting operation. In particular, take measures to protect the bearings from rain water and
dust, for example by covering them with a vinyl sheet.
(2) Store indoor-type motors and other electrical devices indoors.
Also for equipment for outdoor use, protect its wiring and cable openings against moisture.
3.3 Precautions for the location of installation
Install the fan in a place where the following conditions are satisfied:
(1) The fan of standard type is intended for the indoor use. To install it outdoors, choose a place
not exposed to wind or rain water. Furthermore, install the fan in a location where it will not
suck in rain water.
(2) Well-ventilated place with minimum exposure to dust or moisture
If you install the unit in a fully enclosed room, such as a machine room, install a ventilator so
that the room temperature does not increase due to the heat generated by the motor.
(3) Place with an ambient temperature of 0°C to 40°C
(4) Place that is not accessible by unauthorized persons or that is impossible for them to
operate the fan at.
Take measures to prevent unauthorized persons from having access to the fan, for example
by installing a barrier.
(5) Place where the fan can be easily and safely inspected and repaired.
Ensure that there is enough space for assembly, disassembly and repairs of the impeller
and other parts. If fan is installed indoors, make sure there is a doorway large enough to
carry the fan in and out of the room.
(6) In case of installing the fan indoors, provide the margin at the entrance so that the fan can
be moved or transferred.
(7) If it is necessary to frequently replace or repair fans or impellers due to corrosion or wear,
consider using minimal hoisting equipment.
Caution
Do not place any objects that may obstruct ventilation or any
combustibles around the motor.
They may prevent heat from escaping, thus resulting in overheating
or fire.
Note
Note

8
Fan or vibration
insulating base
Mortar facing
Auxiliary
liner
Tapered
liner
Flat liner
Foundation concrete
Fig-2 Liner setting
If the coating film is flawed, perform repair coating to prevent the generation of rust.
3.4 Foundation
(1) The foundation must be strong enough to support the weight and the load and vibration
produced by the fan during operation.
(2) The foundation concrete should be constructed so that it remains level and is not affected by
ground subsidence. Reinforce the ground with driving piles if it is soft or weak.
(3) The weight of the foundation must be 2 to 4 times the mass of the fan including the motor.
(4) The unit’s foundation should be constructed so that vibrations are not transmitted through
the structure’s pillars or floor.
(5) When constructing foundations for two or more units, space each unit appropriately to
prevent the transmission of vibration.
(6) Construct void holes in the foundation concrete the foundation bolt hole.
Refer to the external dimensions drawing for the positions for the foundation bolt holes.
When setting the foundation bolts before installing the fan, use a template to ensure that the
positions are correct.
(7) If the foundation is constructed on the second floor or higher, align the foundation with a
beam and keep it as close as possible to the walls.
3.5 Installation
Floor-mount type
Guidelines for setting the foundation bolts (void type) are noted below.
(When setting the bolt before installation, follow only the applicable directions below.)
(1) Clean the foundation concrete surface and check the levelness. Chipping may be necessary.
(2) Clean the foundation bolt hole and remove any debris.
Although the foundation bolt hole must be wet, water must not pool in the holes. Remove
any excess water.
(3) Set one flat liner and two tapered liners on
both sides of the fan foundation bolt holes as
shown in the figure-2.
If necessary, use auxiliary liners (at least 3
mm thick).
If there is a distance of more than one meter
between foundation bolts, set liners in that
space.
(4) Place the fan or vibration insulating base on
the liners and insert the foundation bolts
through the fan base or vibration insulating
base foundation bolts holes and lower them
into the void holes.
When making the installation earthquake-resistant, weld
the foundation bolts to the reinforcing iron bars of foundation concrete.
(5) Use the tapered liners to adjust the fan position and height.
(6) As a guide, the levelness should be within 0.1 mm per meter.
(7) After making the inner surface of foundation bolt holes rough, fill them with non-shrink
mortar. Set the foundation bolts perpendicularly in the center of the hole.
(8) After the mortar has fully cured, firmly tighten the foundation bolts.
Tighten the bolts uniformly.
Weld the liners to prevent them from moving during operation.
(9) Fill the space between the fan base or vibration insulating base and the foundation concrete
with mortar to make a concrete structure.

9
(10) Check that the mortar has not contracted or cracked.
If drain pipes are necessary, provide a drain pit.
(11) When installing a vibration insulating device, fasten the vibration insulating base with the
foundation bolts.
3.6 Precautions for connecting the ducts
Caution
Do not allow the ducts to exert any load on the fan.
Doing so may result in malfunctions, damage or vibration.
(1) Connect the fan’s flanges and ducts using expansion joints to avoid the transmission of
vibration or noise to the exterior.
Particularly when the fluid is hot, ensure to install the expansion joint to protect the fan from
stress of duct caused by thermal expansion.
(2) Before connecting the ducts, check inside the ducts and fan, and remove any foreign matter,
such as waste cloth and tools.
Warning
Be sure to install a protective wire mesh on any open air intakes of
the fan.
(3) To prevent foreign matter from being sucked into, install a protective wire mesh to the duct
inlet or the air intake of fan where air is sucked directly. If dust or water is expected to get
inside the fan, install a filter to protect against it.
(4) If an inactive (not running) fan is exposed to air in the reverse direction, it rotates in reverse.
Avoid exposure to such air because it takes longer to start a fan that is rotating in reverse.
(5) In general, unexpected pressure loss may occur due to the connection to (a) ducts that are
much smaller than the port diameter of the fan, (b) ducts with a series of bends, or (c) ducts
with bends just before or after the connection to the fan.
(6) When connecting the discharge duct to the product that equips a discharge wire mesh as
standard, remove the discharge wire mesh to connect the duct.
(7) If the intake air is swirling, install guide vanes or increase the radius of the bends.
If necessary, take the same precautions in the suction chamber.
If there is a wall in front of the fan suction inlet, secure the clearance between the suction inlet
and the wall equal to or longer than the diameter of the fan suction inlet.
Note

10
When θexceeds 7°
Wrong
When straight duct is installed
Correct
When bellmouth is attached to
reduce local resistance
Correct
When local resistance becomes
excessive
Wrong
When rectangular bend section
is near to suction port.
Wrong
Attaching vanes at
rectangular bend section
Correct
When bend section is
near to discharge port
Wrong
Attaching vanes at bend or
rectangular bend section
Correct
5D or more
（D means fan
blade dia
）
When vanes of opposite
direction to impeller are
attached near to
discharge port
Wrong
When vanes of same
direction to impeller are
attached near to
discharge port
Correct
When the suction air makes
opposite direction of whirl to
impeller
Wrong
Attaching vanes to prevent
suction air from whirling
Correct
Wrong Correct
Fig-3 Sample piping method

11
3.7 Precautions for wiring work
Warning
Use high-quality wiring equipment and devices, and carry out wiring
work safely and securely according to the technical standards for
electrical facilities, as well as the indoor wiring regulations.
Only qualified personnel such as licensed electrical engineers are
allowed to carry out electrical wiring work.
Unqualified persons are prohibited by law from performing wiring
work and it is very dangerous.
(1) Be sure to install a ground fault interrupter and an overload protection device on the primary
power side of the fan. In case that a thermal relay is used as an overload protection device,
the fan may trip at a start-up due to its starting characteristics.
* The starting current of premium efficiency (equivalent to IE3) motor-equipped products
tends to become higher than that of standard efficiency (IE1) motor-equipped products.
It is necessary to verify the applicability of its ground fault interrupter and overload
protection device. If you have any questions, contact us.
(2) Be sure to install a ground wire to prevent an electric shock.
• Connect the ground wire to the ground terminal inside the terminal box of the fan.
• Do not connect the ground wire to gas pipes, water pipes, lightening arresters, or ground
wires for telephone.
Warning
It is prohibited by law to perform incomplete wiring work, which
exposes personnel to a great danger.
(3) Control the fluctuation of the voltage within ±10% of the rated voltage, and the frequency
within ±5% of the rated frequency.
Note that a sharp fluctuation in voltage and/or frequency may cause damage to the fan as
described in JIS C 4034-1.
(4) Before running the fan, check the following points again:
cAn appropriate fuse (ground fault interrupter) is installed.
dWiring is correct.
eThe product is securely connected to a ground.
fNone of the two or three terminals of the motor has come loose or is disconnected.
Caution
As for models using three-phase power supply, do not operate the
unit with only two terminals connected.
Failure to observe this may cause the motor to burn out.

12
4. Preparation for operation
4.1 Points to be checked before test running
4.1.1 Checking the electrical system
(1) Check that the fan is correctly wired.
(2) Check the frequency.
Running the fan at other than designated frequency may cause performance degradation, or
motor burnout, and damage to impeller and main shaft.
(3) Check that the terminals are securely connected.
(4) Check that the equipment is securely grounded.
(5) Check that the settings of the overload protection device match the rated current value of
the motor being used.
4.1.2 Checking the fan system
(1) Check that water has not accumulated in the fan and that no foreign objects or materials
such as tools have been left inside.
(2) Check that all the connections on foundation bolts, the fan, accessories and pipe joints are
securely tightened.
(3) Check that the dampers and valves can fully open and close, and that they operate normally.
Warning
Always turn OFF the main power before rotating the fan by hand.
(4) Rotate the fan by hand or by inching a motor to check that it can rotate smoothly without any
internal obstructions.
(5) Place an operator in advance so that the fan can be turned OFF immediately after the
instructions of the person in charge of the operation.
Warning
Do not operate the fan if it is not running properly, for example if it is
making a strange noise. Contact a specialist company or the service
company designated by the manufacturer.

13
4.2 Trial run
4.2.1 Precautions at the time of starting the fan
(1) Close the damper and turn the unit ON and OFF once or twice to confirm that the unit is
operating normally without any unusual noise or vibrations. At that time, check the rotation
direction of the fan through the external fan of the motor. To rotate the fan with three phase
power supply in the reverse direction, swap two of the three wires of the power supply cable.
Warning
Be sure to turn off the main power before changing the wiring of the
fan.
Failure to observe this may cause an electric shock.
(2) Turn on the power, and watch the unit closely until it reaches full speed.
At that time, carefully check for unusual noise, vibrations, current, or any other abnormal
condition.
(3) In the meantime, check that there is no defective condition, including abnormal noise,
abnormal vibration, and abnormal current.
Start the continuous operation, and gradually open the damper.
2 In order to check the condition of each part, keep the fan running at a low flow rate (light
load) for 20 to 30 minutes.
At that time, ensure that the fan does not run at a rate where surging may occur.
(4) Gradually open the damper until the fan reaches the full load operation.
Keep it running under the condition for 1 to 3 hours, and check for any vibrations and noise
at each section of the fan.
In addition, check that the motor current value is normal.
Note that the (electrical) current value of the models that handle high temperature air
becomes high during the operation using the room temperature air.
Warning
If the temperature of handling air is high, do not touch the fan main
body or ducts. Failure to observe this may cause burn on the skin.
Also set apart fro flammable gas.
4.2.2 Precautions during the operation
Warning
In the event of a power failure, be sure to turn off the main power.
Otherwise, when the power is restored, the fan suddenly starts, and it
is dangerous.
Frequently starting and stopping the fan quickly damages it. Use the following values as a
guide for the frequency of starting the fan.
Motor output Startup frequency
7.5kW or less Up to 6 times an hour
11kW to 22kW Up to 4 times an hour
26kW or more Up to 3 times an hour

14
Warning
In the event of power failure during operation, be sure to turn off the
power switch. The fan may suddenly start up on restoration of the
power, which leads to a danger.
4.2.3 Precautions when stopping the operation
(1) When stopping the fan, close the damper slowly and then turn the power switch off.
(2) If air exceeding 200°C is used, cool down the inner casing slowly and completely by closing
the damper and running the fan for a certain period. At that time, ensure that the fan does
not run at a rate where surging may occur.
5. Stopping the fan
5.1 Precautions when stopping the use
If you do not use the fan for a long time (more than one month), observe the following points:
Warning
When you leave the fan unused for a long period of time, be sure to
turn off the main power.
(1) When you leave the fan unused for a long period of time, apply appropriate anti-corrosive
agent to the areas prone to rust.
(2) Do not allow any dust or other contaminants to deposit on the fan main body and motor.
(3) Block the inlet at suction side and the outlet at discharge side to prevent deposition of dust
or to prevent intrusion of foreign matters in the connecting duct. If a damper is installed,
close it.
(4) Protect the motor and other electrical devices from moisture.
(5) When you restart using the fan after a long period of shutdown, inspect all parts of the fan
before use.
(6) Manually rotate the impeller shaft once or twice a month to protect the bearing.
(7) During stopping the fan, take measures of providing enclosures or entry lock to prevent
unnecessary access by unauthorized personnel.

15
6. Maintenance and inspection
6.1 Daily inspection
(1) Check the vibration, noise, current value,
etc. of the fan.
If there is any unusual condition, it may be
a sign of failure; therefore, take the
appropriate measures as soon as possible.
For this purpose, it is recommended to
keep an operation log.
(2) If strong vibrations occur, stop operation
and inspect improper duct connections,
tightening of the installation bolts and
foundation bolts, and check for
accumulation of dust on the impeller and
damage to the bearings.
If the vibration is within the range specified
as "Good" in JIS B 8330, it is considered
normal (see the figure on the right).
If a vibration insulating device is installed
on the fan, vibration of the fan itself
becomes slightly stronger although the
vibration is not transmitted to the
foundation. In such a case, a vibration
lower than the broken line is considered
normal.
(3) In addition to vibrations, noise is an
important factor in judging the operating
condition.
If you hear a metallic sound possibly made
by contact into the rotor, stop the operation immediately.
(4) Bearings generate noise even in normal condition.
Although it is difficult to identify an abnormal noise because bearings produce complicated
noise, try and detect it at an early stage with careful attention.
6.2 Periodic inspection
Warning
Before carrying out the inspection of the fan, be sure to turn off the
main power. Otherwise the fan may suddenly start up during
automatic operation etc., exposing personnel to great danger.
Carry out the periodic inspection at least once a year.
The periodic inspection items include the following points, in addition to the daily inspection
items.
(1) Check if there is no extra backlash in the coupling between impeller and motor shaft.
(2) Inspect the impeller and the shaft for corrosion and wear.
(3) Clean the inside of the fan, and apply anti-corrosive agent or otherwise repair the part.
(4) Check that the insulation resistance of the motor has not decreased. At least 1MΩis
required.
n - Rotation (mim-
1
)
Acceptable vibration range
a - Total amplitude (μm)
With vibration isolator
10mm/s
Acceptable
Excellent
Good
(On the motor casing or the bearing housing)
Unacceptable

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7. Troubleshooting
7.1 Troubleshooting
Even if the same failure occurs, the cause and action may be different. In addition, there may be
two or more causes.
If the cause and action cannot be determined using the following table, stop the operation
immediately and contact a specialist company or the service center specified by the
manufacturer.
Caution
Part replacement and repairs should only be performed by specialist
companies.
Improper procedures may lead to malfunctions or accidents.
Failure Cause Action
Strong
vibration
Corrosion or wear in the impeller, or
foreign matter on the impeller
Poor connection between the boss and
shaft of the impeller
Bend of the shaft
Contact between the rotor and casing
Resonant vibration by improper
foundation
Insufficient tightening of the mounting
bolt
Damage to the bearing
Remove the foreign matter adhered to the
impeller, and correct the balance of the
impeller.
Replace the impeller or shaft of the motor.
Replace the motor.
Reassemble the casing.
Reinforce the foundation.
Retighten the bolt and nut.
Replace the bearing.
Abnormal
noise Damage to the bearing
Intake of foreign matter
Contact between the rotor and casing
Replace the bearing.
Inspect the inside of the casing.
Correct the contact between the rotor and
casing.
Low
performance
Decrease in rotational speed or
frequency
Reverse rotation
Corrosion or wear in the impeller, or
foreign matter on the impeller
Clogging of the suction filter
Failure in opening/closing of the damper
Dust deposited inside the casing and
duct
Excessive resistance
Errors in calculating the specific weight
of gas
Regulate the power supply.
Swap the wires of the motor.
Clean, repair, or replace the impeller.
Clean the suction filter.
Repair the damper.
Clean the place.
Consider installing a booster fan.
Measure the specific weight, or perform a
gas analysis.
Motor
overload
Underestimation of actual resistance
Miscalculation of gas density
Adjust with damper
Reduce the rotational speed.

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8. Special accessories
8.1 Dampers
(1) Refer to the external dimensions drawing (supplied separately), and install the dampers in the
designated locations paying attention to the direction of the air flow.
(2) Open and close the vane to check that the blade does not contact the casing or ducts.
(3) For electric, pneumatic or other driving systems, carefully read their instruction manuals.
8.2 Expansion joints
Make the distance between the sides the same as that shown on the external dimensions
drawing, and take care not to pull or compress the joints excessively. Do not use the expansion
joints to correct the fan or duct alignment.
8.3 Filter
Consider installing the fan with short ducts in order to make it easier to disassemble the fan.
Install filters after thoroughly cleaning the inside of the fan and ducts.
Inspect the filter soon after beginning the operation as it tends to clog easily at this time.
Periodically remove the filter element and wash it if possible, or replace with new one.