Unit Start-Up; Variable Frequency Drive (Vfd) Operation - Greenheck APD Installation, Operation And Maintenance Manual

Unit Start-Up

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.
Visual Inspection of Equipment
The equipment type and arrangement should be verified as ordered at once when it arrives at the jobsite. When a
discrepancy is found, the local Greenheck sales representative must be notified immediately so that corrective action
may be investigated, also verify electrical conformance to specifications. Unauthorized alterations and unauthorized
backcharges will not be recognized by Greenheck Fan Corporation.
After the unit has been assembled, installed and all utilities have been hooked up, the unit is now ready for operation.
Check
Before starting the unit, check the following:
1. Confirm that building supply voltage matches the voltage for which the unit is wired.
2. Disconnect and lock-out all power switches to fan. See warning below.
3. Check all piping and wiring penetrations made by contractors for water tightness. All penetrations must be
made watertight to prevent water damage to the unit and building.
4. Check all fasteners, set screws and locking collars on the fan, bearings, drive, motor base and accessories for
tightness.
5. Rotate the fan wheel by hand and assure no parts are rubbing. Remove any dirt or debris that may have
accumulated during installation.
6. Check for bearing alignment and lubrication.
7. Check the V-belt drive for proper alignment and tension.
8. Check all guarding (if supplied) for being securely attached and not interfering with rotating parts.
9. Check all electrical connections for proper attachment.
10. Check for obstructions and foreign material that may damage the fan wheel.
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.
Note: 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. Single phase motors can be reversed by changing internal connections as
described on the motor label or wiring diagram.
2. Fans with multi-speed motors should be checked on low speed during initial start-up.
3. Check for unusual noise, vibration or overheating of bearings. Refer to the "Troubleshooting" section of this
manual if a problem develops.
4. 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.

Variable Frequency Drive (VFD) Operation

Fan vibration levels differ with the method of installation. Operating a fan on a variable frequency drive (VFD) may
experience certain speed ranges with excessively high vibration levels and possible resonant frequencies. Problem
speed ranges or resonant frequencies can be determined during the commissioning process. Either run through this
resonant range as quickly as possible, program out operation at determined Hz to skip over these speeds, or find
alternative remedy.
It is the responsibility of the installing body to perform coast-down tests and identify any resonant frequencies after
the equipment is fully installed. These resonant frequencies are to be removed from the operating range of the fan
by using the "skip frequency" function in the VFD programming. Failure to remove resonant frequencies from the
operating range will decrease the operating life of the fan and void the warranty.
WARNING
Housed Plenum Array, Plug and Plenum
Airfoil Wheel Rotation
Always viewed from
the drive side.
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