Greenheck Fan 90, HRE-20, 55, 45 Direction of Fan Wheel Rotation, Fan RPM, Vibration, unit start-up

unit start-up

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.

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Rotation Direction

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..

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

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..

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