Aprilaire 1750A - Dip Switch Definitions; System Checkout

•ThePrimaryZonetakespriorityduringdehumidifieroperation.PrimaryZonesamplingoccursattheendofeachCyclePeriodandSecondary
Zone sampling occurs at the beginning of each Cycle Period. If the dehumidifier is actively dehumidifying the Primary Zone at the beginning of
the Cycle Period, Secondary Zone sampling will not occur during that Cycle Period. Primary Zone sampling will also override a Secondary Zone
dehumidification demand.
•IfaModel76,Model8910HomeComfortControl
™
, or other Third-Party Control is installed in the Primary Zone, dehumidification of the
Primary Zone will occur on-demand. Secondary Zone sampling will occur at the beginning of each Cycle Period unless actively dehumidifying
the Primary Zone. A Primary Zone demand will override a Secondary Zone demand.
•AttheonsetofPrimaryZonesampling,thedehumidifierdamperoutputturnson,thedehumidifierblowerturnson,andthegreenStatusLED
flashes. After three minutes, the dew point of the incoming air is measured and compared to the setting on the control knob. If the dew point
of the incoming air is above the setting, the compressor turns on and the green Status LED switches to solid illumination. If the dew point is
below the setting, the dehumidifier damper output turns off and the green Status LED begins flashing as the dehumidifier begins Secondary
Zone sampling. After three minutes of Secondary Zone sampling, the dew point of the incoming air is measured and compared to the setting
on the control knob. If the dew point of the incoming air is above the setting, the compressor turns on and the green Status LED switches
to solid illumination. If the dew point is below the setting, the dehumidifier blower turns off along with the green Status LED. (See page 19,
MODEL76EXTERNALCONTROLforPrimaryZonedehumidificationsequencewhenaModel76isinstalled.)
•Thedewpointoftheincomingairiscontinuouslymonitoredduringcompressoroperation.Whenthedewpointoftheincomingairfallsbelow
the setting on the control knob, the dehumidifier damper output turns off and the dehumidifier compressor and blower turn off along with the
green Status LED.
•Afterthedehumidifierblowerhasturnedoff,oneminutemustelapsebeforeitcanbeturnedonagain(i.e.,followingaPrimaryZone
sampling). If one minute has not elapsed, the Status LED will flash and the dehumidifier blower will turn on after one minute.
SEQUENCE OF OPERATION
TWO ZONE – PRIMARY AND SECONDARY ZONED INSTALLATION (CONTINUED)
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