Sequence of Operation
RTU Open v5
CARRIER CORPORATION ©2019
Integration Guide
All rights reserved
37
FREECOOL
Air source fan is on and providing cooling using only the economizer and
usually during an unoccupied period. All zones modulate airflow to maintain
the zone temperature at the occupied cooling setpoint regardless of the
zone’s actual occupancy status.
COOL
Air source fan is on and providing cooling. Equipment SAT is below the
reference zone temperature and all zones modulate airflow to maintain the
zone temperature at the appropriate (occ/unocc) cooling setpoint.
PRESSURIZATION
Air source supply fan is on usually as a result of a fire-life safety input being
active. It may also be used as a safety to increase airflow during a heating
mode. All zones modulate airflow to maintain the zone’s maximum cooling
airflow.
EVACUATION
Air source supply fan is off usually as a result of a fire-life safety input being
active. All zone dampers close and local terminal fans are disabled.
VENT
Air source fan is on and providing ventilation without heating or cooling.
See the air source’s installation manual for more specific operation.