FloAire NSA - Manual (Page 13)

13
Re-Circulating Control Options
Manual Positioning Control (Potentiometer)
The dampers can be controlled at a remote location by a manual potentiometer to any position from 20%
to 100% fresh air. This will allow manually setting the dampers to match the building ventilation
requirements. It will take an extra 3 control wires at the remote location. On a power failure, or if the unit is
turned off, the return air damper will close by spring return.
Two Position Control
The dampers can be controlled by a two position switch (a field supplied switching device) to open the
fresh air to 100%. On opening of the circuit, power failure, or if the unit is shutoff, the return air damper
will close by spring return.
Static Pressure Control (Photohelic)
The dampers can be controlled by a building static pressure control. This controller will sense the
difference between pressure inside the building, and pressure outside the building (sensed at the A306
outdoor sensor), and position the dampers to maintain the pressure setting on the controller. The
controller has two set points and an indicator. The two set points are a minimum desired static pressure
point, and a maximum static pressure point.
The actual building static pressure will be shown by a visual indicator between these two settings. The
controller will modulate the dampers to maintain a static pressure between these set points.
When building static pressure is below the minimum setting, the damper motor will proportionally open
the fresh air damper and close the return air damper until static increases above the minimum setting. At
this point, the damper motor will stop and hold this proportion.
If the building static continues to climb and goes above maximum setting, the damper motor will reverse
proportion, closing the fresh air damper and opening the return air damper until static drops below
maximum setting.
During the “OFF” or “Night” cycle of the unit, an internal switching circuit will close the return air damper.
See additional wiring and installation information on the static pressure controller and A306 outdoor
sensor.
Static Pressure Controller Installation Instructions
Avoid locating the front of the static pressure controller in sun light or other areas with high ambient light
or corrosive levels. Bright light shining on the photocells can cause false actuation of the load relays.
The static pressure controller should be zeroed out before attaching the low and high pressure hoses.
The zero adjustment is located between the minimum and maximum dials.