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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:
("Vent")
— 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:
("Low Cool")
— This is a normal cooling mode when a low cooling
demand exists.
HVAC mode:
("High Cool")
— This is a normal cooling mode when a high
cooling demand exists.
HVAC mode:
("Low Heat")
— This is a normal heating mode when a low
heating demand exists.
HVAC mode:
("High Heat")
— This is a normal heating mode when a low
heating demand exists.
HVAC mode:
("Unocc. Free Cool")
— 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.
}
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:
("Shutting Down")
Summary of Contents for WeatherExpert 48N2
Page 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Page 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Page 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Page 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Page 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Page 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Page 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Page 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Page 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Page 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Page 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Page 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Page 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...