FläktGroup LQLA Plenum fan Installation and Maintenance Manual
- Type
- Installation and Maintenance Manual
FläktGroup DC_10396GB 20191216_R0 Specifications are subject to alteration without notice
LQLA PLENUM FAN, DIRECT-DRIVEN
INSTALLATION AND MAINTENANCE INSTRUCTION
Content Page
Installation options ........................................................................................2
Checks to be made prior to commissioning ......................................2
Electrical connections ..................................................................................2
Measures before starting ...........................................................................3
Installation of separately supplied frequency inverters ..................3
General ............................................................................................................... 3
Frequency inverter ........................................................................................3
Airflow measurement ...................................................................................3
To connect the shelded cable .................................................................. 4
Maintenance .....................................................................................................5
To remove the fan from the air handling unit casing,
Asynchronous and PM-motors .................................................................5
To replace the motor .................................................................................... 5
2
Installation and maintenance instruction
FläktGroup DC_10396GB 20191216_R0 Specifications are subject to alteration without notice
ELECTRICAL CONNECTIONS
The motor of the fan must always be controlled by a frequency inverter.
The frequency inverter permits control of the motor speed and slow
starts.
CHECKS TO BE MADE PRIOR TO COMMISSIONING
• Check that the fan complies with the EU machinery directive.
All inspection doors on the fan section and other function is
equipped with door locks with a key. Additional safety can be
added. LQLZ-39 is a protective screen which can be placed at
the inlet to the fansection. LQLZ-36 is a protective screen that
can be added to the outlet of the fan section if another AHU func-
tion is placed downstream of the fan. LQLZ-64 is protective
screen when the fan section is placed at the outlet of the AHU.
LQLZ-38 is additional protection behind the inspection door at
the fansection.
• Check that a qualified electrician has handed over written
approval for commissioning.
• Check that the fan impeller rotates freely and that no objects
which can be drawn in and damage the fan have been left in
the installation.
• If the fan is equipped with steel spring anti-vibration mountings,
the transport locking devices must be removed before starting
the fan.
LQAZ-64
Protective screen
LQAZ-63
Counterflange
LQAZ-61
Flexible connection
LQAZ-62
Connection piece
Connection
Accessories for the
outlet:
LQLZ-36 Safety
guard, outlet
LQLZ-39
Safety guard, inlet
LQLZ-38 Protective
screen for door
Important!
If the fans are idle for more than 3 months
prior to or after installation, the fans should
be occasionally rotated by hand at regular
intervals. If this is not done, the bearings are
liable to become damaged due to overloading as
shown in the adjacent illustration.
N.B.!
The fan must not be started directlyon-line!
Read the MAX permissible frequency at which
the fan motor may be controlled. You’ll find this
frequency specified on the rating plate. Under
no circumstances is it permissible to supply
the fan motor with power of a higher frequency.
Belastningsskador
Deformations due
to overloading
LQLA FAN, INSTALLATION OPTIONS
3
Installation and maintenance instruction
FläktGroup DC_10396GB 20191216_R0 Specifications are subject to alteration without notice
The LQLA plenum fan is supplied with a factory-fitted shielded cable,
wired to the terminal box of the motor. The cable between the terminal
box of the motor and the separate frequency inverter must be shielded. A
safety isolating switch must be installed between the mains supply and
the frequency inverter. Install the safety isolating switch near the inspec-
tion door of the fan.
Before beginning work on the fan, isolate the power supply by switching
off the safety isolating switch.
The LQLA plenum fan can be supplied with an external, factory-fitted
frequency inverter, wired to the terminal box of the motor with a shielded
cable. A prefitted safety isolating switch prewired to the frequency invert-
er is also available as an accessory.
The LQLA plenum fan can also be supplied with a factory-fitted shielded-
cable run to an external shielded terminal box.
MAX frequency
Electric wiring must be carried out by a qualified
electrician.
Important!
Isolate the power supply and wait until the im-
peller has stopped rotating (approx. 1 minute)
before inspecting and servicing the fan.
There may be designs of duct systems that
causes wind milling which prevents the impeller
from being stopped. The wind milling must then be
prevented;
1) turn off the power to the fan
2) close the dampers.
INSTALLATION OF SEPARATELY SUPPLIED
FREQUENCY INVERTER
Warning!
If the frequency inverter is not installed
correctly, this may damage the motor bearings.
FläktGroup’s policy stipulates that we agree
to accept guarantee liability only if the motor and
frequency inverter have been supplied
and installed by us.
Guarantee liability will not be accepted by
FläktGroup if the motor has been connected/wired
to a frequency inverter by another fitter, i.e. one who
is not employed by or commissioned by FläktGroup.
Note!
The frequency inverter have been optimized for the
duty point. The power could thus be lower than the
motors rated power.
MEASURES BEFORE STARTING
The fan must not be started with the damper on the suction or delivery
side closed. However the fan motor may be briefly
energized with the inspection door open for checking that the direction of
impeller rotation is correct.
Check before starting the fan that the impeller rotates freely and that no
objects, which can be drawn in and damage the fan, have been left in the
installation.
If the fan is equipped with steel spring anti-vibration mountings, the
transport locking devices must be removed before starting the fan.
FREQUENCY INVERTER
The shielded cable must be led either through an EMC approved
cable gland in the casing of the frequency inverter or through a cap
intended for this purpose.
The shielded cable must not be connected to an earth screw.
The frequency inverter and motor shall be installed by a qualified
electrician with adequate knowledge on how to install speed-con-
trolled drive systems (frequency inverters) and EMC safety.
The following recommendations shall be regarded as a comple-
ment to the manufacturer’s installation instructions. If the content of
the instructions differ, the instructions furnished by the manufactur-
er shall have priority over those stated below, to enable compliance
with the guarantee liability terms of the manufacturer of the equip-
ment.
GENERAL
A continuous, shielded 4-wire cable designed for EMC installation
to motorized drives between the motor and the frequency converter
is supplied with the fan. The optical density of the cable shield shall
be at least 80 %, e.g. NCY or Olflex Classic. The shield must be in
360 º contact with the casing both in the motor and in the frequency
inverter in order to achieve maximal surface contact. It is not advis-
able to install a safety isolating switch or junction boxes between the
frequency inverter and the motor.
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xx xx
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xxx
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The shield must be in
360º contact with
the casing
Shield
Insulating tape
4
Installation and maintenance instruction
FläktGroup DC_10396GB 20191216_R0 Specifications are subject to alteration without notice
CAPACITIES IN EXCESS OF 22 KW
If the capacity exceeds 22 kW, a symmetrically shielded cable with
concentric or in some other way symmetrically designed protective
earth conductor should be used. For recommendations governing
these installations we refer to the installation instructions for the
frequency inverter.
TO CONNECT THE SHIELDED CABLE
If the application requires you to wire the cable shield to an
earthscrew inside the motor or the frequency inverter, this must be
done in such a way that the impedance will be as
low as possible. In these cases the length of this conductor must
be restricted to 5 times the width of the conductor.
For instance, the length of a 1 cm wide conductor should
not exceed 5 cm.
OTHER DETAILS
In addition to the above, observe the following:
• type of mains power supply
• local electrical safety rules and regulations
• manufacturer’s installation instructions for the frequency
inverter.
Insulating tape
q = 1 · Δp m3/s
k
Important!
For LQLZ-42 U-tube manometers, use only
the blue manometer fluid supplied with the
instrument. Never use any other type of fluid.
Precision-adjust the zero point with the zero
adjustment screw.
If the air handling unit is supplied with a control system, the flow
can be read directly in the control panel display.
NB!
In the case of air handling units supplied with a
control system, the pressure tappings in the end
connection panels of the unit are not connected to
the airflow sensor of the fan.
If you still want to read the manometer pres-
sure with an external manometer, you can connect
the tubes from the airflow sensor of
the fan across T-nipples to the pressure tap-pings
in the end connection panel of the air handling unit.
If this external means of measuring flow will not
be permanent, the tubes must be restored to their
original condition.
If two fans are installed in the fan section, the k-value is applicable to
the total airflow generated by both fans.
q = q20 , m3/s
(273 + t)
293
TEMPERATURE CORRECTION
The flow scale on the indicating instrument and the flow formula
above apply to air with a temperature of +20 °C. For other tempera-
tures, the flow must be corrected using the following formula:
where q = the actual flow through the fan, q20 = the flow reading and t
= the current temperature in °C.
Size LQLA-aa-b k-factor Fan size
60-1, 62-1 5,37 80
60-2, 62-2 4,24 90
60-3, 64-1, 66-1, 71-1, 73-1, 80-1 3,43 100
62-3, 64-2, 66-2, 71-2, 73-2, 75-1, 80-2, 82-1 3,40 2x071
64-3, 66-3, 73-2, 75-2, 82-2, 84-1 2,69 2x080
64-4, 66-4, 73-4, 75-3, 82-3, 84-2 2,12 2x090
75-4, 84-3 1,71 2x100
A flow indicator with built-in pressure transducer (available as
an accessory) should be connected by means of tubes to the
external pressure tappings. This instrument converts the mano-
meter pressure reading to a flow (m3/s) which is shown on a
display screen and transmits a 0–10 V output signal, linear with
the flow.
The LQLA has equipment for measuring the airflow.
The airflow, q, can be measured by applying a manometer
reading of Δp (Pa), and a constant, k, using the following formula:
The manometer reading, Δp, which is the difference between the
pressure in the suction chamber by the fan inlet and the pressure
inside the inlet cone, can be read with a manometer (pressure
range of up to 6000 Pa) which should be connected
with a 4 mm dia. tube to 2 externally located pressure tappings.
The value of the constant k is specified in the table below.
AIRFLOW MEASUREMENT
5
Installation and maintenance instruction
FläktGroup DC_10396GB 20191216_R0 Specifications are subject to alteration without notice
6. Push in and reassemble the components in the reverse order.
In cases where there is no possibility to carry out the entire fan
or motor with impeller, alternatively there is no need for a com-
plete disassembly, following procedure can be used:
1. NOTE! Turn off the power at the main switch and mark that
work is ongoing in the fan section.
2. Disconnect all electrical connections in the motor terminal
box.
3. Remove the motor bracket from their bolted joints at the unit’s
bottom panel/guide rails.
4. Move the motor bracket with motor and impeller from the inlet
cone far enough to enable removal of the impeller.
5. Alternatively loose the bolt joint on the motor and rotate the
motor to enable removal of the impeller.
6. Remove the impeller from the motor shaft using a puller.
7. Lift the impeller out of the unit in a suitable way through the
inspection door or disconnect the motor bolted joints if this
has not been done and lift the motor out of the unit in an
appropriate way through the inspection door.
MAINTENANCE
The fan must be inspected and cleaned every 6/12th month. The
length of the interval has been determined on the basis of approx.
2000 hours of operation during a 12-month period and for a normal
comfort installation.
In environments where the dust content is high in the supply and/
or extract air, the air handling unit will have to be inspected and
cleanedmore often.
The fan is accessible through the inspection door and cleaned with
the fan in place.
CLEANING
Both the supply air and the extract air fan should be inspected and
cleaned whenever the need arises. Dust tends to collect mainly on
the inner side of the fan blades.
The best way to clean the fan impeller is by using a vacuum cleaner
equipped with a soft nozzle. Be careful to remove all the impurities
from the fan blades so that the fan will not come out of balance.
After adjusting or cleaning the fan, check that it runs free of vibra-
tion.
Warning!
In order to prevent personal injury and damage
to machinery, the safety isolating switch must be
switched off and the safety fuses of the fan must be
removed before beginning work on
the fan.
Important!
Make sure that the fan inlet engages into
the rear holder of the connection frame.
TO REMOVE THE FAN FROM THE AIR HANDLING
UNIT CASING, ASYNCHRONOUS AND PM-MOTORS
The fan can be withdrawn from the casing in the following way:
1. Remove the frame of the inspection door including the door
and the fixed panel by removing the bolts beneath the cover
plenums.
2. Disconnect the motor cable/control cable to the frequency
inverter and pull the cables through the rotor wall/filter wall.
3. If a pressure suppressor and steel spring anti-vibration
mountings are fitted: Remove the nuts to the fan beams in
the floor at both ends.
4. If steel spring anti-vibration mountings are fitted:
Remove the bolts that hold the fan connection against
the fan outlet.
5. Withdraw the fan unit. Be careful not to damage the gasket
in the fan’s inlet plate (applies to rubber antivibration
mountings).
The fan can be withdrawn maximally so far out that half the
fan motor protrudes outside the unit casing without support.
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Locking
bolt
TO REPLACE THE MOTOR
1. Disconnect the electrical connections.
2. Remove the stop screw in the fan impeller hub.
3. Remove the motor from the motor base plate.
4. Extract the impeller from the motor shaft end with an
extractor tool. Utilize the existing extraction grooves in
the hub for this purpose. See the figure below.
5. Back the motor from the impeller.
6. Reassemble in the reverse order, using the tapped hole in
the motor shaft end as a fixing point for the extractor tool.
Carry out maintenance on the motor according to the instructions
provided by the motor supplier.
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FläktGroup LQLA Plenum fan Installation and Maintenance Manual
- Type
- Installation and Maintenance Manual
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