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BALTIDRIVE
®
including changes achieved by the use of a variable fan speed device, steps must be taken to avoid
operation at or near the fan's "critical speed" which could result in fan failure and possible personal injury or
damage. Contact your local BAC Representative regarding any such applications.
motor associated with this equipment. Before performing any type of service of inspection, make certain that
all power has been disconnected, and the switch is locked out in the "OFF" position.
•
If the unit is already in operation, while the fan is running, check for any unusual noises or vibrations.
•
With the fan off and the fan motor disconnected, 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).
o
Check the fan blades for looseness, first by twisting the blade by hand, and then by moving the blade tip
o
forward and back. There should be no play or slippage.
Inspect each blade for excessive scale build-up that could cause vibration.
o
Check each blade for any cracks. If cracks are found, the fan motor should be locked out until the fan is
o
replaced. 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
3/16" to 1/4".
Independent Fan Control (Optional)
NOTE: With evaporative cooling, a 15 second fan motor delay will not be noticed when staging
up.
NOTICE: For a unit with a VFD, with a switching frequency of 2.5 kHz, the line lead length
cannot exceed 100 feet. If the switching frequency is higher than 2.5 kHz and/or the line lead
length exceeds 100 feet, a dV/dT output filter is recommended to protect the motor. Since the
switching frequency and maximum line length requirements vary between VFD and motor
suppliers, contact your local BAC Representative to determine if a dV/dT filter is required. For
fan motors controlled with VFDs, when reversing the direction of fan rotation, allow the fan to
come to a complete stop before restarting the motor.
Vertex™ Evaporative Condenser Operation & Maintenance Manual – Fan Control
Power Train
: When the fan speed of the unit is to be changed from the factory set speed,
: A lockable disconnect switch should be located within sight of the unit for each fan
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