17
17
Optional Gear Drive System
Gear drive systems are optional for dual air intake FXV3/CXVT units only.
Initial Startup
• If the unit is equipped with the extended oil fill option, make sure the ball valve
located at the gear box is open prior to start-up.
• BAC ships all gear drives filled with oil. The initial oil level should be at or near the
middle of the oil level sight glass.
• Internally mounted gear drives are factory installed, aligned, and tightened. Double
check all gear drive fasteners after the unit has been installed.
• On units with externally mounted motors, install and align the motor and drive shaft
in accordance with BAC’s installation instructions. Recheck the alignment and all
external fasteners after two weeks of operation.
• On installations with variable frequency drives, do not operate the standard gear drives
below 450 RPM motor speed (gear input speed). For speeds less than 450 RPM, a
low speed option gear drive must be supplied.
• Prior to the start-up, check all fittings on the gear drive to ensure that there are no
visible leaks. Refer
Figure 6
for locations of the gear drive fittings.
Air Breather Plug
Oil Level
Sight Gauge
Oil Drain Plug
Oil Fill Elbow
Name Plate
Figure 6.
Single Reduction Gear Drive
Change Interval
•
Initial oil change
: Replace the original oil after 500 hours or four weeks of operation,
whichever comes first.
• After the initial oil change, change the oil every 2,500 hours or six months, whichever
comes first.
• Drain the oil at the operating temperature through the drain plug.
• Refill the gear drive through the oil fill elbow with the recommended type and amount
of lubricant (
Table 3
). Refer to
Figure 6
for locations of these components.
NOTICE:
Gear drives should not be
used with Wye-Delta (Y-
) motors.
NOTE:
Continued operation at a
speed which resonates with the
gear drive system may result in
torsional vibrations which can
damage system components. The
most common indicator of torsional
vibration is an unusual rumbling or
grinding noise from the gear drive
at a narrow speed range. The noise
will decrease to normal levels when
the speed is increased or decreased
away from the offending speed
range. This noise is not indicative
of a defect, but results when the
vibratory torque exceeds the drive
torque, causing the gear teeth to
separate and clash together very
rapidly. On variable frequency
applications, avoid operation near
this resonance speed by locking out
the resonance speed range.
