Data Aire dap4 User Manual page 73

MENU M – Set Zone Master (continued)
Avg Rack - The Zone Master will modulate the fan speed of all running
units in the zone to the average rack temperature. This selection requires
optional rack temperature sensors.
C Air Prs - The Zone Master will modulate the fan speed of all running units
in the zone to maintain static air pressure. If all units have an air pressure
sensor installed, the master will use the lowest usable reading. Otherwise
the master will use its air pressure sensor.
This screen will only appear if Fan Mode is set to "C. Flow".
Zone AF SP - The airflow set point for the zone in cubic feet per minute.
This set point is the same one that appears on the "Zone Airflow" screen in
the set points loop.
Integration Time – This setting determines the time before modulation will
be changed to eliminate the difference between measured and set point.
Band Factor – This setting is how tight to the set point that modulation will
swing. The larger the band, the less swing in modulation.
Derivative Time – This setting determines how sudden the modulation
should change as a result of a change in measured air flow. It attempts to
eliminate "overshooting" the set point.
Assist on Demand – Allows you to set the amount of fan demand where a
standby unit will be requested to run (after the Standby On time setting
described below). For example; if set to 75%, the master would request a
standby unit to turn on when fan modulation reaches a demand of 75%.
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