Data Aire dap4 User Manual page 44

MENU J – FACTORY SETTINGS (factory level) continued
Note: The Variable Compressor screen is only displayed when the compressor
selection is set for a variable compressor.
The variable compressor will modulate to maintain the mode selected in the
previous screen.
Band: This setting determines 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, compressor speed may lack responsiveness. Ideally, the band
setting should be as low as possible without causing oscillation. Range of
adjustment is 1.0 to 99.0°F with a default of 18.0°F. (48.0 for IRDX model).
Integration Time: (Only shown when control set to P+I or PID). Used to slowly
shift the compressor speed level to correct the error between temperature reading
and set point. The higher Integral time setting, the slower the compressor speed
will change. If the Integral time is set too low the compressor speed could change
quickly, causing oscillation. If Integral time setting is too high, compressor speed
may become sluggish to change. A setting of 0s puts the algorithm in a
proportional only mode. Range of adjustment is 0 to 5000s.
If set to Discharge Temp Control: default is 60s.
If set to Return Temp Control: default is 1000s.
Derivative Time: (Only shown when control set to PID). Causes a sudden change
in fan speed to correct the error as a result of a quick change in temperature.
Typically, the derivative setting is about a sixth of the Integral time setting. Range
of adjustment is 0 to 999s with a default of 5s.
C1 Offset: Is the amount that the temperature must drop below the Setpoint
before the variable compressor is turned off. Range of adjustment is 0.0 to 9.9°F
with a default of 1.0°F (2.0°F default if set to control discharge air temperature).
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