BAC PCT Series, Operation & Maintenance Manual

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8
W W W . B A L T I M O R E A I R C O I L . C O M . A U
M A R 1 0 8 - 2
WARNING: Do not perform any
service on or near the fans,
motors, and drives, or inside
the unit without first ensuring
that the fans and pumps are
disconnected, locked out, and
tagged out.
WARNING: Check to ensure the
controls for the fan motor are set
to allow a maximum of six on-off
cycles per hour to prevent motor
overload.
Fan
The PCT Cooling Tower uses axial fan(s). Thoroughly inspect the
fan(s) for damaged or deteriorated fan blades and replace the fan(s)
as required.
Inspection & Maintenance
• If the unit is already in operation, while the fan is running, check for
any unusual noise or vibration.
• With the fan off and the motor locked out and tagged out, check the
general condition of the fan:
– Inspect for any loose or missing bolts in the fan shaft bushing,
the fan hub, and the fan shaft bearing(s).
– Check the fan blades for looseness, first by twisting the blade
by hand, and then by moving the blade tip up and down. There
should be no play or slippage.
– Inspect each blade for excessive scale build-up that could
cause vibration.
– Check each blade in the area of the shank for any signs of
cracking. If cracking is found, the fan motor should be locked
out immediately. Contact your local BAC Representative for
assistance.
• Tip Clearance: Check the clearance between the tip of the blade and
the fan cowl. The clearance should be between 3mm and 13mm.
• Blade Pitch: Check to ensure that the blades are all at the same
pitch. If uncertain, measure the pitch with an inclinometer. All
blades should be /-1/2°.
• Rotation: Turn the fan by hand to ensure that it moves freely with
no rough spots, binding, or other malfunctions that could cause
vibration or fan motor overload. While rotating the fan, check the
blade tracking. All blades should track within a 13mm band at any
single point around the cowl.
•
Direction of Rotation:
On initial start-up, or if the fan motor has
been rewired, bump the fan motor and note the direction of
rotation. It should rotate in the direction indicated by the arrow on
the fan cowl.
• Operation: On initial start-up, run the fan in the manual position for
several minutes and check for any unusual noises or vibration.