Pre-Start-Up Checks - Greenheck Vektor-H Installation, Operation And Maintenance Manual

Vektor-H Applications with Variable Frequency Drive (VFD)
For Vektor systems with single-point, three-phase wiring per blower, the isolation damper actuator will be powered
via a step-down transformer, which is wired to the fan disconnect, as shown in the wiring diagrams on page 10.
If fan flow (motor speed) is to be controlled using
a variable frequency drive with this wiring, the
reduced voltage and frequency supplied to the
fan will cause control problems with the isolation
damper actuator.
When a project's Vektor control sequence requires
the use of a VFD, it is suggested that the control
contractor supply the isolation damper actuator
voltage, independent of the power supplied to the
Vektor fan motor.

Pre-Start-Up Checks

Check all fasteners for tightness.
Check radial gap, overlap and wheel alignment. The wheel should be aligned as shown. Although the wheel position
is preset and the unit is test run at the factory, movement may occur during shipment.
The radial gap should be consistent at all locations between the centrifugal wheel and the inlet cone. Centering may
be accomplished by loosening the inlet cone bolts and repositioning the inlet cone.
To obtain the optimum performance, the centrifugal wheel must overlap the inlet cone.
Adjustments can be made by loosening the set screws in the wheel and moving the
wheel to the desired position.
Wheel rotation should be in the same direction as the rotation decal affixed to the
unit. (Counterclockwise rotation is correct as viewed from fan inlet). For 3-phase
installations, fan rotation can be reversed by simply interchanging any two of the three
electrical leads. For single phase installations, follow the wiring diagram located on the
motor.
NOTE
Any increase in fan speed represents a substantial
increase in horsepower required from the motor.
Always check motor load amperage and compare to
nameplate rating when changing fan speed.
Belt Drive
Inlet Cone to Backplate
A Dimension
Unit
±
Tolerance
Size
Inches
9 3-3/16 ± 1/8
10 3-7/16 ± 1/8
12 4 ± 1/8
± 1/8
13 4-7/16
16 5-7/16 ± 1/8
± 1/8
18 6-3/8
± 3/16
22 7-13/16
24 8-5/8 ± 1/4
30 10-9/16 ± 3/8
± 3/8
36 12-3/4
Radial Gap is adjusted by loosening the inlet cone bolts and centering the cone on the wheel. If additional
adjustment is required to maintain a constant radial gap, loosening the bearing bolts and centering the wheel is
acceptable as a secondary option.
Overlap or offset, is adjusted by loosening the wheel hub from the shaft and moving the wheel to the desired
position along the shaft. The transition between the inlet cone and wheel should be as shown above; there is a
smooth feel to the profile when moving from one component to the other.
®
For Vektor-HS fans provided from the factory with a VFD,
refer to the Vektor Laboratory Exhaust with Variable Geometry
Nozzle (VGN) Technology Electrical Controls Installation,
Operation and Maintenance Manual for electrical wiring and
connection information.
A Dimension
Unit
±
Tolerance
Size
millimeter
81 ± 3 10
87 ± 3 12
13
102 ± 3
± 3 14
113
138 ± 3
16
± 3
162 18
± 5
198 20
219 ± 6
268 ± 10
± 10
324
NOTE
Direct Drive
Inlet Cone to Backplate
A Dimension A Dimension
± ±
Tolerance Tolerance
Inches millimeter
3-1/2 ± 1/8 89
4-5/16 ± 1/8 125
4-7/8 ± 1/8 124
5-7/16 ± 1/8 138
± 1/8
6-1/16 154
6-7/8 ± 1/8 175
± 1/8
7-11/16 195
Wheel
Inlet
Cone
A
Overlap
Radial Gap
± 3
± 3
± 3
± 3
± 3
± 3
± 3
Laboratory Exhaust System 11