Specifications

27
Dedicated Outside Air
When in cooling mode, if the unit is equipped with modulating hot gas re-heat valve, it will be
enabled and modulated to maintain supply air temperature set point, factory default is 55 °F (adj.)
+/- 2°F.
The cooling stages are reset with outside air temperature (OAT) as it changes as follows:
Mechanical Heating 45 °F <OAT < 49°F
Free Cooling 50 °F <OAT < 59°F
Mechanical Cooling Part Load OAT > 60 °F (adj.)
Mechanical Cooling Full Load OAT > 75 °F (adj.)
All values have a hysteresis of 2.5 °F.
Any of the following alarms will immediately shut all compressors stages down:
• Leaving water high
• Leaving water low
• Fan alarms
• Status Switch
• High Static
• Smoke
Reversing Valve Operation
A reversing valve is used to change the direction of the refrigerant installed on units that are
configured as heat pump equipment (heating and cooling). The reversing valve is energized on a
call for cooling and will remain energized until a call for heating. Upon a call for heating, the
reversing valve is de-energized and remains de-energized until a call for cooling. The
compressor will be disabled and remain off for 10sec after the reversing valve has changed
position. The reversing valve logic can be reversed.