SPX Marley NC8409 - Page 12

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4. Momentarily bump (energize) 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.
5. Run the motor and observe the operation of the mechanical equipment. Opera-
tion should be stable, and there should be no evidence of oil leakage.
6. If equipped with belt drive check the torque on the fan and motor sheave
after 10 to 60 hours of operation. See Bushing Fastener Torque Values of
the Belt Tensioning and Sheave Alignment section of this manual.
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.
installation
Caution
Note