HVAC MODES
By default, the HVACModeCmd (A287) is set to 0, for automatic operation. The VAV will heat and cool as
configured. If the HVACModeCmd (A287) is set to any other value, it will operate as described below. (The
occCmd (A269) will be disabled if any value other than Auto is selected).
• 0 = Auto (default)
• 1 = Morning Warmup
• 2 = Morning Cooldown
• 4 = Heat Only
• 8 = Cool Only
• 16 = Fire Stop
• 32 = Purge
WARM-UP/HEATING STATE
If the HVACModeCmd (A287) analog setpoint has been set for Morning Warm-up, or there has been hot
air detected from the AHU supply air temperature, the unit will change to Occupied Mode and maintain
the occupied heating setpoint. The mechanical heat (duct and perimeter heat) will be disabled. The
damper will modulate to maintain the heating airflow setpoint, which will reset based on the heating
demand.
The heating airflow setpoints will be substituted with the cooling airflow setpoints. On a call for more
heat in an area, the airflow setpoint will reset up to the maximum cooling airflow setpoint, instead of
the maximum heating airflow setpoint for maximum heat gain.
Once the room has met the setpoint, the airflow setpoint will return to the minimum heat setpoint.
COOL-DOWN/COOLING STATE
The unit will change to Occupied Mode and maintain the occupied cooling setpoint. The damper will
modulate to maintain the cooling airflow setpoint, which will reset based on the cooling demand.
Heating will be disabled.
HEAT ONLY
The unit will change to Occupied Mode and maintain the occupied cooling setpoint. The damper will
modulate to maintain the heating airflow setpoint, which will reset based on the heating demand.
Cooling will be disabled.
COOL ONLY
The unit will change to Occupied Mode and maintain the occupied cooling setpoint. The damper will
modulate to maintain the cooling airflow setpoint, which will reset based on the cooling demand.
Heating will be disabled.
FIRE STOP COMMAND
The unit will close the primary air damper and de-energize all fans and stages of heat and cooling.
PURGE COMMAND
The unit will set primary airflow setpoint to max Flowrate setpoint and de-energize all fans and stages of
heat and cooling.
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