Installation Guide

12 English
WIRING TO THE HVAC SYSTEM
When the dehumidifier is ducted to the HVAC system,
it is recommended that it also be wired to the HVAC
system as shown in
Figure 20 . If ducted to the HVAC
system in a return-to-return configuration, the
dehumidifier must be wired to the HVAC system to
prevent short-circuiting dehumidified air directly
back to the dehumidifier inlet. In a return-to-supply
ducting configuration, running the HVAC fan with the
dehumidifier ensures the warm dry air is mixed with
room air before being discharged to the home.
OPTIONAL W & Y WIRING
Wire the W and/or Y terminal to the HVAC system when
using the ventilation feature of the dehumidifier.
See
Ventilation on page 13.
Wire the dehumidifier Y terminal to the HVAC system to
disable the dehumidifier compressor from operating
when the air conditioning is running.
See Allowing DEH
W/AC on page 16
for additional setup steps required
to access this feature.
+-AB ODTVENT DEH
Sensor DampersRemote
FLOAT
Switch
DH DH
GhRf Cf Gs YW
HVAC EQUIP.
G
R
C
W
Y
R
C
G
W
Y
1
2
4
3
5
90-1859
Figure 20: Wiring to HVAC System
1 - Existing Wire
2 - New Wire
3 - Thermostat or Zone
Control Board
4 - HVAC Equipment
5 - Optional Wires
WIRING TO EXTERNAL OR REMOTE
CONTROLS
The dehumidifier can be wired to an external control
that senses the humidity in the living space, such as
an AprilAire Thermostat or the Model 76 Dehumidifier
Control. This is most often done when the dehumidifier
is ducted to the HVAC system and is located in a
hard-to-reach location such as an attic or basement.
The Model 76, when used as a remote control,
allows the user to see the humidity sensed by the
dehumidifier and adjust the dehumidifier setting from
a remote location. This is most often used when the
dehumidifier is not ducted to the HVAC system and
serves a hard-to-reach location such as a crawl space
or basement.
If using an external control, wire to the DH terminals
of the dehumidifier
(see Figure 21) . Most external
controls use a normally open switch that closes with
a dehumidification demand, in which case leave the
NC/NO switch in the NO position. For controls that use
a normally closed switch, put the NC/NO switch in the
NC position. If using the AprilAire Model 76 as a remote
control, wire to the {+ - A B} terminals. Refer to the
installation instructions for the control being used for
wiring details.
1
2
90-2694
Figure 21: Wiring to an External or Remote Control
1 - Use for External
Control Applications
2 - Use for Remote
Control Applications
WIRING TO A FLOAT SWITCH
Use only if the installation includes a float switch or
a condensate pump. The dehumidifier leaves the
factory with a jumper wire installed in the float switch
terminals. Remove the jumper and wire the float switch
terminals to the float switch or condensate pump
overflow switch as shown in
Figure 22 .