7
Mechanical Equipment
Always shut off electrical power to the tower fan motor prior to performing
any maintenance on the tower. Any electrical switches should be locked
out and tagged out to prevent others from turning the power back on.
1. If equipped, check oil level in accordance with the
Geareducer User Manual
for the Geareducer. If oil is required, fill Geareducer to the proper level with
approved lubricant.
2. Spin the fan manually to assure that all fan blades properly clear the inside
of the fan cylinder. Observe the action of the sheaves and belts to be sure
that the motor is properly aligned with the fan sheave. See Belt Tensioning
and Sheave Alignment on page 16 and 17. If equipped with Geareducer
drive observe the action of the coupling (or drive shaft couplings) to be sure
the motor and Geareducer are properly aligned. If necessary correct align-
ment (see
Geareducer User Manual
).
3. Momentarily energize (“bump”) the motor and observe rotation of the fan.
The fan should rotate in a counterclockwise direction when viewed from
below. If rotation is backwards, shut off the fan and reverse two of the three
primary leads supplying power to the motor.
If tower is equipped with a two-speed motor, check for proper rota-
tion at both speeds. Check also to see that starter is equipped with a
20 second time delay which prevents direct switching from high
speed to low speed. If the fan is intended to be reversed for deicing
purposes, make sure that the starter is equipped with a two minute
time delay between changes of direction. These delays will prevent
abnormal stress from being applied to the mechanical equipment
and the electrical circuit components.
5. Run the motor and observe the operation of the mechanical equipment. Operation
should be stable.
6. If equipped with belt drive check the torque on the fan and motor sheave
after 10 to 60 hours of operation.
If the water supply system is not being operated—or if there is no
heat load on the system—motor amps read at this time may indicate
an apparent overload of as much as 10–20%. This is because of the
increased density of unheated air flowing through the fan. Deter-
mination of an accurate motor load should await the application of
the design heat load.
Warning
Caution
Note
installation
