SPX Cooling Technologies MARLEY AV 98-1514E - Manual (Page 11)

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necessary, correct the alignment. See the Maintenance section for
belt tensioning and sheave alignment—page 22.
Improper installation of the fan guard will destroy the structural in-
tegrity of the fan guard. It is essential that the fan guard be installed
in accordance with the Field Installation Manual shipped with the
tower. Do not force the fan cylinder out of round.
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 2 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.
4. Run the motor and observe the operation of the mechanical equip-
ment. Operation should be stable.
5. After the first 30 minute run check motor AMPS and voltage with full
water and heat load. Repitch fan, if necessary—correct for low ambi-
ent temperatures. Refer to motor manual.
6. After 10 to 60 hours of operation check the torque on the fan and
motor sheave bushings and check belt tension. Refer to the Main-
tenance section of this manual for torque values and belt tensioning
instructions—page 22.
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. Determi-
nation of an accurate motor load should await the application of the
design heat load.
Caution
Warning
Note
Installation