Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service, And Troubleshooting page 242

APPENDIX E — MODE SELECTION PROCESS (CONT)
HVAC mode: ("Off")
— The unit is off and no operating modes are active.
HVAC mode: ("Tempering Vent")
— The economizer is at minimum vent position but
the supply-air temperature has dropped below the
tempering vent set point. Gas or hydronic heat is
used to temper the ventilation air.
HVAC mode: ("Tempering LoCool")
— The economizer is at minimum vent position but
the combination of the outside-air temperature and
the economizer position has dropped the supply-air
temperature below the tempering cool set point.
Gas or hydronic heat is used to temper the
ventilation air.
HVAC mode: ("Tempering HiCool")
— The economizer is at minimum vent position but
the combination of the outside-air temperature and
the economizer position has dropped the supply-
air temperature below the tempering cool set point.
Gas or hydronic heat is used to temper the
ventilation air.
HVAC mode: ("Venting Dehum")
— The unit is operating in Vent mode and dehumidifica-
tion is in effect
HVAC mode: ("Cooling Dehum")
— The unit is operating in Cool mode and dehumidifica-
tion is in effect
HVAC mode: ("Heating Dehum")
— The unit is operating in Heat mode and dehumidifi-
cation is in effect
HVAC mode:
— This is a normal operation mode where no heating
or cooling is required and outside air is being
delivered to the space to control IAQ levels.
HVAC mode:
— This is a normal cooling mode when a low cooling
demand exists.
HVAC mode:
— This is a normal cooling mode when a high
cooling demand exists.
HVAC mode:
— This is a normal heating mode when a low
heating demand exists.
HVAC mode:
— This is a normal heating mode when a low
heating demand exists.
HVAC mode:
— In this mode the unit will operate in cooling but
will be using the economizer for free cooling.
Entering this mode will depend on the status of the
outside air. The unit can be configured for outside
air changeover, differential dry bulb changeover,
outside air enthalpy changeover, differential
enthalpy changeover, or a custom arrangement
of enthalpy/dew point and dry bulb. See the
Economizer section for further details.
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NOTE: There is also a transitional mode whereby the machine
may be waiting for relay timeguards to expire before shutting
the machine completely down:
HVAC mode:
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("Vent")
("Low Cool")
("High Cool")
("Low Heat")
("High Heat")
("Unocc. Free Cool")
("Shutting Down")