10-2014 gForce User Manual ● 105
change the amount of the deadband before the valve will be repositioned. The
temperature can be slowly drifting back and forth within a deadband window at
any point in the adjustment period and no valve position changes will be made.
If the current temperature is higher than temperature setpoint, the following
sequence is used to determine the new valve position.
Current Temperature = Setpoint + Deadband + 0.0ºF = 0% Position
Current Temperature = Setpoint + Deadband + 0.1ºF = 10% Position
Current Temperature = Setpoint + Deadband + 0.2ºF = 20% Position
Current Temperature = Setpoint + Deadband + 0.3ºF = 30% Position
Current Temperature = Setpoint + Deadband + 0.4ºF = 40% Position
Current Temperature = Setpoint + Deadband + 0.5F = 50% Position
Current Temperature = Setpoint + Deadband + 0.6ºF = 60% Position
Current Temperature = Setpoint + Deadband + 0.7ºF = 70% Position
Current Temperature = Setpoint + Deadband + 0.8ºF = 80% Position
Current Temperature = Setpoint + Deadband + 0.9ºF = 90% Position
Current Temperature = Setpoint + Deadband + 1.0ºF = 100% Position
The chilled water valve proportionally closes 10% for each 0.1ºF below the
temperature setpoint + 1.0ºF.
If the current temperature is lower than at the last adjustment period, the
following sequence is used to determine the new valve position.
Current Temperature = Setpoint + 1.0ºF = 100% Position
Current Temperature = Setpoint + 0.9ºF = 90% Position
Current Temperature = Setpoint + 0.8ºF = 80% Position
Current Temperature = Setpoint + 0.7ºF = 70% Position
Current Temperature = Setpoint + 0.6ºF = 60% Position
Current Temperature = Setpoint + 0.5ºF = 50% Position
Current Temperature = Setpoint + 0.4ºF = 40% Position
Current Temperature = Setpoint + 0.3ºF = 30% Position
Current Temperature = Setpoint + 0.2ºF = 20% Position
Current Temperature = Setpoint + 0.1ºF = 10% Position
Current Temperature = Setpoint = 0% Position
When unit switches to DX mode because chilled water temperature is higher
than Energy saver chilled water setpoint or because of the temperature is higher
than setpoint plus deadband plus the energy saver change- over band, dap4™
will use the DX cooling logic above to maintain the return air temperature
setpoint. All DX safeties are applied.
To Next Page
Loading...
