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ACC-APG002A-EN
controller will modulate supply fan speed to maintain Duct Static Pressure relative to the Duct Static
Pressure Setpoint.
Duct Static Pressure High Limit
The controller operates the supply fan to maintain duct static pressure below the Duct Static Pressure
High Limit setpoint. In the event that duct static pressure approaches the high limit setpoint, the
controller will reduce and limit the supply fan speed.
Unoccupied Cooling
Unoccupied Cooling mode is used when the building is unoccupied and the space conditions are
exceeding temperature limits. The unit is normally off in unoccupied mode. If a valid space temperature
input rises above the Unoccupied Cooling Setpoint, unit operation starts unoccupied cooling to manage
space temperature. The controller operates in Discharge Air Control with ventilation disabled while DX
or economizer cooling capacity increases to satisfy the Discharge Air Cooling Setpoint. VVDA System
Type operate the supply fan under duct static pressure control. Cooling continues until space
temperature is 4°F less than the Unoccupied Cooling Setpoint, the unit will then cycle off.
Unoccupied Heating
When the unit is in unoccupied mode and the valid space temperature input falls below the Unoccupied
Heating Setpoint, unit operation starts unoccupied heating to manage space temperature. The controller
operates in Discharge Air Control with ventilation disabled while heating capacity increases to satisfy
the Discharge Air Heating Setpoint. The supply fan operates according to heat type installed, see Heat
Types for more information. Heating continues until space temperature is 4°F greater than the
Unoccupied Heating Setpoint, the unit will then cycle off.
Variable Volume Discharge Air Control Sequence of Operation
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