Greenheck Vektor Laboratory Exhaust with VGN Technology Electrical Controls Information (476072) - Manual (Page 25)

System Test and Balance for VGN
The VGN Technology control system needs to be set
up at a desired fixed fan speed and nozzle area. If the
following is not done, it will be difficult to do the test
and balance of the building as the fan will continually be
adjusting during changes in the building lab airflow. The
following steps listed are necessary to create a stable
fan system for the test and balance setup of a building.
The following steps need to be taken to do the test and
balance of the VGN system:
1. Set the VFD fan speed parameter to a desired fixed
position for testing.
2. Locate the main system control panel and access
the system controller.
a. At the controller, page thru the menu and locate
the “Test and Balance” screen.
NOTE: See “Controller Menu” screen for more
details.
b. At the “T&B Balancing” line select “YES” to
activate manual nozzle control.
c. Set the “Nozzle % Open” line to the desired fixed
value, the nozzle will not modulate and will remain
in the fixed position.
d. Take airflow measurement(s) and determine fan
flow in the system.
e. Compare controller “Fan Flow” at the menu
screen to the measured flow value in step “D”
f. Adjust the fan flow value by adjusting the “Flow
Correct” to match the airflow that was measured.
g. If the system is now balanced, change the
following at the “Test and Balance” menu.
• T&B Balancing line = NO
• Nozzle % open = 0
Nozzle Velocity Adjustment
The VGN Nozzle Controller is shipped from the factory
to output an average 3000 fpm (912 mpm) nozzle
velocity. The velocity can be adjusted by the user to
range between 3000 to 4000 fpm (912 to 1216 mpm).
The velocity is set as default from the factory as English
but can be changed to Metric.
The following steps can be done to adjust the nozzle
velocity range of the fan.
1. Locate the main system control panel and access
the system controller.
a. At the controller, page thru the menu and locate
the “System Settings” screen.
NOTE: See “Controller Menu” screen for more
details.
b. Move down the variable list to the “Outlet
Velocity” value. Note the default is 3000 fpm
(912 mpm).
c. To change the value use the up/down arrows
and adjust the velocity to the desired value
within the system range and press the enter key
to finalize the value.
These steps conclude the Nozzle Velocity portion of the
Nozzle Controller VGN system.
Electrical Controls Information for Customer-Supplied Variable Frequency Drive
25 VGN Technology
®