SPX Cooling Technologies MARLEY MH MHF705 - Manual (Page 12)

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It is essential that the fan cylinder and fan guard be installed in ac-
cordance with the drawings shipped with the tower. Do not force the
fan cylinder out of round.
4. Momentarily bump (energize) the motor(s) and observe rotation of the
fan(s). 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 equip-
ment. Operation should be stable, and, if equipped, there should be
no evidence of oil leakage from the Geareducer.
6. If equipped with belt drive check the torque on the fan and motor sheave after
10 - 60 hrs. of operation. See Bushing Fastener Torque Values on page 25.
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.
Note
Installation
Note
Caution