Aprilaire 1750A Dehumidifier User Manual


 
THIRD-PARTY CONTROL
WIRING & DIP SWITCH CONFIGURATION
An external thermostat with dehumidifier connections can be used as an ON/OFF dehumidifier control. In this configuration, the third-party
control initiates dehumidification and overrides the on-board dehumidifier control logic. The dehumidifier control knob can only be used to initiate
Test Mode when a third-party control is used. The Convertible configuration is not available with a third-party control.
FIGURE 28 – Third-Party DIP Switch Configuration
90-1538
LOCAL
CONVERTIBLE
EXTERNAL
SYSTEM SETUP
HVAC FAN ON
VENT-TIMED
VENT-AUTO
WHL HOUSE
HVAC FAN OFF
ON
1 2 3 4
90-1537
DAMPERS
Rf DH -WGhGs
Cf
VENT
HVAC EQUIP REMOTE
DEH B +A
G
R
C
G
W
Y Y
W
C
R
Deh
Deh
SENSOR
ODT
FLOAT
SWITCH
DEHUMIDIFIER
CONTROL BOARD
HVAC EQUIPMENTTHERMOSTAT
THIRD-PARTY CONTROL
Wiring Notes:
The dehumidifier Rf and Cf terminals must be powered from the
transformer that powers the third-party control.
Third-Party Control with 2 Dehumidifier Connections
1. Connect one thermostat dehumidifier terminal to the Rf terminal on
the dehumidifier control board.
2. Connect the other thermostat dehumidifier terminal to the DH
terminal on the dehumidifier control board.
Third-Party Control with 1 Dehumidifier Connection
Connect the thermostat dehumidifier terminal to the DH terminal on
the dehumidifier control board.
SEQUENCE OF OPERATION
•Whenthethird-partycontrolmakesadehumidificationcall,thedehumidifierdamperoutputturnson,thedehumidifierblowerturnson,and
the green Status LED flashes.
•After3secondsthecompressorturnsonandthegreenStatusLEDswitchestosolidillumination.
•Whenthethird-partycontrolendsadehumidificationcall,thedehumidifierdamperoutputturnsoffandthedehumidifierblowerand
compressor turn off along with the green Status LED.
FIGURE 27 – Third-Party Control Wiring
NOTE: Deh output(s) must
be normally open.
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