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5.11 Assembly of Complete Knock
Down Unit (CKD)
Due to container size constrain, some air
handling units are packed in unassembled
condition - CKD method. All parts required
are packed in section by section. It is
recommended to open one section at a
time to avoid confusion when assembly.
For CKD, additional drawing will be
provided for assembly at site.
5.12 Component Removal and
Replacement
5.12.1 Panel Removal
To remove side or top panel, simply
unscrew the fasteners located along the
aluminum clip on the frame of Air
Handling unit cabinet. Once the aluminum
clips are removed, lift the panel off.
5.12.2 Fan / Motor
The fan shaft, motor and drive
components can be removed and replace
through the access door opening or side
panel removal if additional access required.
For fan replacement, the entire fan
assembly can be pulled out from side or
front (for top discharge) of the cabinet.
Dismantle the intermediate fan supports
and canvas follow by loosening bolts &
nuts at motor and drive belts. Then
remove the belts and nuts from Fan
mounting frame. Take out the fan and
replace with new fan with care. Re-
connect the shaft and bearings and fan
assembly.
5.12.3 Coil
The coil can be pulled out from side or top
of cabinet. The coil is fastened with bolts
and nuts on the coil support bracket at the
end plate and baffle plate. Before removal
of coil, ensure the piping connections at
header are disconnected. In case where
two coils are stacking, remove the drip
pan and join brackets which holding the
two coils together.
For DX coils, it is advisable that the
refrigerant is to be pumped into the
condenser. If this is not possible,
refrigerant shall be purged out.
WARNING
DO NOT HEAT ANY PART ON DX
COIL IF REFRIGERANT STILL IN
THE SYSTEM. HEATING UP WILL
CAUSE
DANGER
OF
HIGH
PRESSURE INSIDE THE COILS.
6. Commissioning and Operation
6.1 Pre-run Check
6.1.1 Preparation
The complete air handling unit and all
accessory
components
should
be
thoroughly cleaned and all dust & debris
completely removed.
Make sure that all transport brackets and
packing have been removed.
Ensure all screws, bolts and nuts on AHU
are secured tightly (not loose during AHU
transportation or handling).
Ensure all panel and belt drive settings are
secured due to change during shipment or
installation.
In case additional equipment is installed at
site, ensure air leaking spots are being
seal with additional baffle plates or seal
with silicone to prevent air bypassing.
WARNING
ISOLATE THE ELECTRICAL &
MECHANICAL ENERGY SOURCE
AND PADLOCK THE SWITCH
BEFORE SERVICING THE FANS
AND MOTORS.
6.1.2 Fan / Motor
Make sure the fan impeller can rotate
freely by hand. Check the tension and
alignment of the belt drive.
Check motor connections and make sure
correct voltage is supplied. If standby
motor is available, make sure only one
motor to power source.
Seal end of fan motor conduit (if
applicable) and the motor terminal box
with silicon sealant.
VFD/Frequency Inverter for TEFC motor
can only vary the frequency within 30 to
60 Hz in order to control the motor
rotation speed. For VFD setup, make sure
the
VFD
settings
according
to
recommendations at VFD manual.
When multiple fan with multiple VFDs,
fans must set up to always start
simultaneously and with same speed.
