Data Sheet for Product

Unoccupied Cooling Mode
When the space temperature rises beyond the unoccupied cooling setpoint, the fan starts. If
free cooling is available, and the OA damper is enabled for unoccupied operation, the
Predator modulates the damper to maintain the discharge setpoint and cools the space. If
further cooling is required, the Predator modulates the chilled water valve to maintain the
discharge setpoint. When the space temperature drops, the valve and damper close and the
fan shuts off. The hot water valve stays closed.
Unoccupied Heating Mode
When the space temperature drops below the unoccupied heating setpoint, the fan starts.
The Predator modulates the hot water valve to maintain the discharge setpoint and warms the
space. When the space temperature rises, the valve closes and the fan shuts off. The OA
damper and the chilled water valve stays closed.
Unoccupied Dehumidifying Mode
When the humidity in the space goes above the setpoint, the Predator starts the fan, opens
the cooling coil valve, and operates the hot water valve to temper the discharge from the unit
and prevent overcooling the space. The OA damper stays closed. When the humidity in the
space drops (below the level defined by the space humidity setpoint minus a deadband), the
Predator maintains the heating or cooling mode if necessary, or it shuts off the fan and the
coils.
Bypass Mode
Occupants may put a room into bypass mode by pressing a button on the thermostat. This
runs the equipment as in the occupied mode during periods scheduled for un-occupancy.
Morning Warm-up
During warm-up, the Predator applies the occupied heating setpoint. It may be configured to
run at full heat capacity, at a fixed discharge temperature, or to gradually apply heating as in
the occupied mode. It does not dehumidify during warm-up as in the occupied mode.
Control Sequence Diagram
100% Open
Damper
Minimum
0%
Heating
Valve
Cooling
Valve
Air Conditioning Load
Outdoor Air
Damper
Document No. 588-153 Page 3 of 12