To: Site Technicians and Service Contractors responsible for PM Service and Repair

Subject: Changing the Free Cooling Differential Setpoint

Related Products: All ASLLC Series Controllers (ASLLC.2, ASLLC.2.48, ASLLC.2A, ASLLC.2A.48)

Background: The Free Cooling function standard on all AIRSYS units introduces large amounts of outside air into sites. Without enough exhaust capability, Free Cooling may induce undesirable overpressure in the building. To mitigate this, the free cooling differential setpoint can be increased. This setting is the minimum difference between the indoor and outdoor temperatures needed for free cooling to start. By increasing this difference, free cooling will only start when the outdoor temperature is very cool and therefore introduces less air into the building.


Instructions

  1. Press Up until Set is displayed.
  2. Press Down and Sel together, the screen should display a flashing 0. If this is not the case, return to step 1.
  3. Press Up until the screen displays 6 and press Sel, the screen will display L01.
  4. Press Up until the screen displays L04 and press Sel, the screen will display U01.
  5. Press Down until U06 is displayed and press Sel. 
  6. Use the Up and Down buttons to change the Free Cooling Differential Setpoint to 16°F.  After this change, free cooling will only be enabled if the difference between the indoor and outdoor temperatures is greater than 16°F.
  7. Press Sel to confirm the setting, then press Up and Down together to return to the indoor temperature.