Greenheck Fan Laboratory Exhaust System Vektor-HS - Manual (Page 8)

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 7.
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.
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.
Unit
Size
Inlet Cone to Backplate
A Dimension
± Tolerance (in.)
A Dimension
± Tolerance (mm)
9 3 3/16 ± 1/8 81 ± 3
10 3 7/16 ± 1/8 87 ± 3
12 4 ± 1/8 102 ± 3
13 4 7/16 ± 1/8 113 ± 3
16 5 7/16 ± 1/8 138 ± 3
18 6 3/8 ± 1/8 162 ± 3
22 7 13/16 ± 3/16 198 ± 5
24 8 5/8 ± 1/4 219 ± 6
30 10 9/16 ± 3/8 268 ± 10
36 12 3/4 ± 3/8 324 ± 10
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; there is a smooth
feel to the profile when moving from one component to
the other.
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. (Clockwise
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. Radial Gap
Overlap
A
Inlet
Cone
Wheel
NOTE
For Vektor-HS fans provided from the factory with
a VFD, refer to the Vektor-HS SAVVE controls
Installation, Operation and Maintenance Manual
for electrical wiring and connection information.
8 Laboratory Exhaust System
®