Greenheck Fan HEAT RECOVERY UNIT WITH EVAPORATIVE COOLING HRE-20 - Manual (Page 33)

33
Vibration
Excessive vibration may be experienced during initial start-up . Left unchecked, excessive vibration can cause
a multitude of problems, including structural and/or component failure . The most common sources of vibration
are listed below .
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, in-place balancing can be done .
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 .
1 . Wheel Unbalance
2 . Drive Pulley Misalignment
3 . Incorrect Belt Tension
4 . Bearing Misalignment
5 . Mechanical Looseness
6 . Faulty Belts
7 . Drive Component Unbalance
8 . Poor Inlet/Outlet Conditions
9 . Foundation Stiffness
UNIT START-UP
R
o
ta
tio
n
R
o
ta
tio
n
Rotation
Rotation
Backward Inclined
Forward Curved
Airflow
Airflow
Rotation Direction
R
o
ta
tio
n
R
o
ta
tio
n
Rotation
Rotation
Backward Inclined
Forward Curved
Airflow
Airflow
Direction of Fan Wheel Rotation
Blower access is labeled on unit . Check for proper wheel rotation by momentarily
energizing the fan . Rotation is determined by viewing the wheel from the drive
side and should match the rotation decal affixed to the fan housing (see Rotation
Direction figures) . If the wheel is rotating the wrong way, direction can be reversed
by interchanging any two of the three electrical leads .
Check for unusual noise,
vibration, or overheating of bearings . Refer to the Troubleshooting section of this
manual if a problem develops .
Fan RPM
Supply fan and exhaust fan will have an adjustable motor pulley (on 15 HP and
below) preset at the factory to the customer specified RPM . Fan speed can be
increased or decreased by adjusting the pitch diameter of the motor pulley . Multi-
groove variable pitch pulleys must be adjusted an equal number of turns open or
closed . Any increase in fan speed represents a substantial increase in load on the
motor . Always check the motor amperage reading and compare it to the amperage
rating shown on the motor nameplate when changing fan RPM . All access doors
must be installed except the control center door . Do not operate units with access
doors open or without proper ductwork in place as the fan motors will overload.