Quick Start Guide

Application Sheet 2 – Single Zone Using External Control
Figure 3 Wiring (shown without “disable
with AC” feature being used)
Parts Needed (additional parts may be required):
__ Model 1830/1850/1870 __ Thermostat wire
__ Insulated duct __ 20A Outlet (1870 only)
__ Duct fittings & hardware __ Model 76, Model 8620
__ Grilles (if required) or Model 8910 control
__ Drain Pan and Float Switch (if required)
Figure 1 Dehumidifier Ducted to HVAC System
Figure 2 Dehumidifier Ducted Directly
External Control
The external control (i.e. Aprilaire Model 76
Dehumidifier Control, Model 8620
Thermostat or Model 8910 Home Comfort
Control) must have a normally open (NO –
all Aprilaire controls are normally open type)
or normally closed (NC) dry contact output,
and must be installed in the space that is
going to be dehumidified. Select the type of
control using the NO/NC dip switch on the
dehumidifier control.
Sequence of Operation
When the external control calls for
dehumidification, the dehumidifier blower
the HVAC blower (if this option has been
wired – see Figure 3) turn on, then three
seconds later the compressor turns on. All
will turn off when the external control stops
calling for dehumidification.
HVAC EQUIPMENT
RETURN
SUPPLY
HVAC EQUIPMENT
RETURN
SUPPLY
HVAC EQUIPMENT
RETURN
SUPPLY
Main Return to Main Supply
Main Return to Main Return - Recommended
Dedicated Return to Main Supply or Return