8
Model BCSW-FRP
Vibration
Excessive vibration is the most frequent problem
experienced during initial start-up.
Left unchecked, excessive vibration can cause a
multitude of problems, including structural and/or
component failure.
Many of these conditions can be discovered by careful
observation. Refer to the troubleshooting section
of this manual for corrective actions. If observation
cannot locate the source of vibration, a qualified
technician using vibration analysis equipment should
be consulted. If the problem is wheel unbalance,
the wheel should be sent back to the factory to be
properly rebalanced.
Greenheck performs a vibration test on all centrifugal
fans before shipping. Three vibration readings are
taken on each bearing in the horizontal, vertical, and
axial directions. The allowable maximum vibration
for belt drive units is 0.078 in/sec. peak (0.05 in/
sec. direct drive) velocity filter-in at the fan RPM per
AMCA Standard 204. These vibration signatures are a
permanent record of how the fan left the factory and
are available upon request.
Generally, fan vibration and noise is transmitted
to other parts of the building by the ductwork. To
eliminate this undesirable effect, the use of heavy
canvas connectors is recommended. If fireproof
material is required, Flexweave
TM
1000 - Type FN-30
can be used.
Common Sources of Vibration
1. Wheel Unbalance
2. Drive Pulley Misalignment
3. Incorrect Belt Tension
4. Bearing / Coupling Misalignment
5. Mechanical Looseness
6. Faulty Belts
7. Drive Component Unbalance
8. Poor Inlet/Outlet Conditions
9. Foundation Stiffness
Unit Start-Up
1. Disconnect and lock-out all power switches to fan.
See warning below.
2. Check all fasteners, set screws and locking collars on
the fan, bearings, drive, motor base and accessories
for tightness.
3. Rotate the fan wheel by hand and assure no parts
are rubbing.
4. Check for bearing alignment and lubrication.
5. Check for coupling alignment (Arr. 8 only).
6. Check the V-belt drive for proper alignment and tension.
7. Check all the guarding (if supplied) for being securely
attached and not interfering with rotating parts.
8. Check all electrical connections for proper
attachment.
9. Check housing and ductwork, if accessible, for
obstructions and foreign material that may damage
the fan wheel.
10. Check that the drain is connected, or plugged, and
the housing is being properly drained.
Additional Steps for Initial Start-Up
1. Check for proper wheel
rotation by momentarily
energizing the fan. Rotation
is always determined by
viewing the wheel from
the drive side and should
correspond to the rotation
decal affixed to the unit.
One of the most frequently
encountered problems with
Centrifugal Fans is motors
which are wired to run in the
wrong direction. This is especially true with 3-phase
installations where the motor will run in either
direction, depending on how it has been wired. To
reverse rotation of a 3-phase motor, interchange any
two of the three electrical leads.
2. Check for unusual noise, vibration or overheating of
bearings. Refer to the “Troubleshooting” section of
this manual if a problem develops.
3. Grease may be forced out of the bearing seals
during initial start-up. This is a normal self-purging
feature of this type of bearing.
WARNING
Disconnect and secure to the “Off” position all
electrical power to the fan prior to inspection
or servicing. Failure to comply with this safety
precaution could result in serious injury or death.
Clockwise Rotation
Always viewed from
the drive side.
