5
VGN Technology
®
The VGN system uses a variable geometry nozzle to
maintain desired nozzle outlet velocities. The VGN
system is controlled by a pre-programmed VGN
controller. The VGN controller powers the factory
mounted pressure transducer and the variable geometry
nozzle. The VGN controller receives a signal from
the pressure transducer and converts that signal into
a fan flow. It then calculates the appropriate nozzle
opening and sends a signal to the nozzle to adjust it
to the proper size opening to maintain desired nozzle
outlet velocity. The VGN controller does not operate the
isolation or bypass damper and it does not control duct
pressure; those parameters are controlled by the BMS.
Mounting of VGN Controller
Mount VGN controller upright with connectors down
on structural support within 20 feet from center of fan
plenum. Cables and wiring will be connected to the
bottom of the box so it must have a minimum of 12
inches of clearance from any obstructions. The VGN
control box is a NEMA-3R enclosure suitable to be
mounted indoors or outdoors.
Nozzle to Pressure Transducer Box Quick
Disconnect Wiring Instructions
Connect the factory supplied 5 pin cable (shipped in
the pressure transducer box mounted on the fan) to the
5 pin threaded bulkhead on the bottom of the nozzle;
connect the other end to the 5 pin threaded bulkhead
on bottom of the pressure transducer box that is
mounted on the fan. Mount provided adhesive cable
clips every 12 inches down the fan stack and secure
cable using zip ties.
NOTE:
Repeat this step for fan number 2, 3, 4 if
applicable.
VGN Controller to Pressure Transducer Box
Quick Disconnect Wiring Instructions
Connect the factory supplied 8 pin cable (shipped in
the VGN controller) to the 8 pin threaded bulkhead on
bottom of the VGN controller; connect the other end to
the 8 pin threaded bulkhead on bottom of the pressure
transducer box that is mounted on the fan. Each fan is
provided with (3) 10 meter cables that can be connected
together to extend the length; use as required per fan.
Based on the location of the VGN controller, each fan
may require a different number of cables to reach the
controller; it is not necessary to match the number of
cables used on each fan.
NOTE:
Repeat this step for fan number 2, 3, 4 if
applicable. Make sure the numbering of the fans is
consistent during the entire wiring installation; fan 1 will
require wiring specific to fan 1, fan 2 will require specific
wiring, along with fans 3 and 4 if applicable
Variable Geometry Nozzle (VGN) System Function Overview
