Data Aire dap4 User Manual page 38

MENU J – FACTORY SETTINGS (factory level) continued
Ramp Pause delay: This sets the minimum time that the fan speed will not
change when fan speed meets current demand. Range of adjustment is 1 to 5
minutes with a default setting of 2 minutes.
Note: The Static Air Pressure (or Differential Air pressure) screen is only displayed
when CW or DX fan mode is set to modulate to maintain Air Pressure.
The dap4 uses a proportional integral algorithm (P+I) to maintain air pressure. The
description of the settings offered below is only a guide. The difference between
the set point and the actual measured air pressure is called the error.
Set Point: The pressure (inches or water coulomb) that the fan speed will
modulate to maintain. Range of adjustment is 0.001 to 9.999"Wtr with a default
setting of 0.500"Wtr.
Band: This setting is effectively the "sensitivity" of the algorithm. The smaller the
band, the more the algorithm will try to correct the error. If the band setting is too
low, the system will oscillate by being over-responsive. If the band setting is
too high, fan speed may lack responsiveness. Ideally, the band setting
should be as low as possible without causing oscillation. Range of adjustment
is 0 to 32767cfm with a default of 666cfm.
Integration Time: Used to slowly shift the fan speed level as a result of an error
between set point and t h e measured a i r p re s s u re . The h ighe r Integral time
setting, the slower the f an speed level will be shifted. If the Integral time is set
too low the f a n sp e e d could ch a n g e quickly, causing oscillation. If Integral
time setting is too h igh , fan speed may become sluggish to change. A
setting of 0s (default) puts the algorithm in a proportional only mode. Range of
adjustment is 0 to 999s.
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