Aerovent IM-301 - Manual (Page 2)

2 Aerovent IM-301
2.2 LIFTING
AXIAD fans should be lifted using slings. Note that on
AXIAD fans the slings should be placed under the skids, and
the spreader bars used as required. Under no circumstances
should the vane section be used for lifting.
2.3 MOUNTING
Depending on the type of fan support specified, the
fan can either be horizontally floor mounted on legs, horizon-
tally supported on a structural frame, horizontally ceiling hung
with clips or support brackets, vertically floor mounted on a
frame, or vertically ceiling hung.
2.3.1 Vibration Isolators
The fan is dynamically balanced to reduce vibration to
a low level. However, it is recommended that the fan be sup-
ported on vibration isolators. Isolators should be selected for
each installation in accordance with individual requirements.
The weight distribution between mounts is not equal
on AXIAD II fans. Consult the factory for isolator selection
or mount loads. Isolators should be selected to support the
unequal load with equal deflection. A subbase can be used to
equally distribute the load to the isolators. Concrete inertia
pads are generally not required on axial fans.
2.3.2 Fan Reactions
It is essential to minimize fan movement due to starting
torque and air thrust force. These forces must be resisted to
maintain duct alignment and prevent damaging the flexible
connectors. Isolators must be selected with adequate stiffness
to resist these forces. Snubbers may be required in some instal-
lations to limit the fan movement.
2.4 DUCT CONNECTIONS
All fans should be closely aligned with the ductwork. A
flexible connection should be provided between the fan and
duct to prevent structure-borne noise from being transmitted
to the ductwork. Use band clamps and seal with Borden’s
Arabol, or equal, to insure mechanical security and prevent
leakage on all flexible connections.
NOTE: Provide a 1-inch to 2-inch gap between the fan
and duct to allow for fan movement.
2.4.1 Diffuser and Cone Connection
On AXIAD II fans, the discharge cone and diffuser
can be directly connected to the fan and thus become a part
of the load to be isolated. On Arrangement 4 Type 2 AXIAD
fans inlet cones can be directly connected and they also
become part of the load to be isolated.
2.4.2 Inlet Bell Connection
The inlet bell may be mounted in a plenum wall with a
flexible connection between the outer edge of the bell and a
hole in the partition. Provide a 2-inch to 3-inch gap to allow
for fan movement.
The inlet bell may be installed protruding into the ple-
num where space is limited. A metal ring should be installed
between the inlet bell and the case flange and a flexible con-
nection installed between the ring and the plenum wall.
2.5 ELECTRICAL
All wiring should conform to local electrical codes and
the job specification. In NEMA standard MG-2, NEMA
addressed the phenomena of transient torques. We advise that
measures be taken to protect your equipment from transient
torque and power interruptions.
2.5.1 Power Connection
The motor leads terminate in the conduit box. The
leads are factory connected for the voltage specified for the
job. Motor leads for wye-delta and part-winding starts are not
connected. Rigid conduit should be run from the motor
starter to the fan with a short section of flexible conduit at the
conduit box to allow for fan movement.
Wire size and motor overloads should be sized in
accordance with the fan nameplate electrical data. The conduit
box is located on the outside of the case on all ducted, direct
driven fans. If the motor is outside the fan case, connection
will be made directly to the motor.
2.5.2 Motor Rotation
Check motor rotation by jogging the motor. The rota-
tion should be clockwise when viewed from the inlet of the
fan. Reverse any two motor leads to change rotation.
NOTE: It is important that correct motor rotation be
established on ducted fans as the rotor will not be visible after
an inlet duct is installed.
2.5.3 Electrical Data
The fan should be started in accordance with Section
2.5.4 and the electrical data measured and compared to motor
nameplate ratings.
2.5.4 Final Check Before Putting
Fan Into Operation
1. Check for correct supply voltage and motor overloads.
2. Insure that all loose debris is removed from fan, fan room,
plenum and/or all ducts.
3. Check that motor bolts are tight and rotor is centered in fan
case with adequate blade tip clearance all- around.
4. Hand rotate and then bump the fan starter to check rota-
tion.
5. Start the fan and verify that the vibration is acceptable.
3.0 AXIAD II FAN BLADE ADJUSTMENT
3.1 GENERAL
The AXIAD II FTFA fan is an adjustable pitch fan.
The blade pitch has been factory set to meet the airflow
requirement of the job specification. The pitch may be
changed to meet other airflow requirements on the jobsite.
Each blade has cast into it a number of raised marks with
grooves in between and the fairing has a register mark
machined into it at each blade opening. See Figure 2, which
identifies each of the ridges and grooves with a number from
0 to 9. These numbers correspond to the performance curve
numbers shown in the AXIAD II design performance manual.