Ventilation And Fan Cycling - Aprilaire 1700 Safety And Installation Instructions Manual

VENTILATION / FAN CYCLING SETTINGS
The Aprilaire Dehumidifier has the option
to monitor HVAC heating, cooling and fan
calls to assure the HVAC blower has
operated a predetermined amount of
time each 1/2, 1, 2 or 3 hours. The
dehumidifier can also open a normally
closed damper in a fresh air intake to
ventilate during this predetermined
amount of time. This feature will
function even if the dehumidifier is
turned off at the dehumidifier or living
space control. The only way to disable
this feature is by turning the Cycle Time
setting to OFF or turning power off at the
On/Off switch near the power cord.
First, set the 1/2, 1, 2 or 3 hour period by setting the CYCLE PERIOD dip switches to determine
how often the dehumidifier should look to ventilate or cycle the HVAC fan.
Next, use the CYCLE TIME potentiometer to determine how long during every cycle period the
HVAC blower should operate. Adjust the potentiometer from OFF anywhere from 1 to 60 minutes.
This will give you HVAC blower operation from 1 to 60 minutes every 1/2, 1, 2 or 3 hours. A call
for heat, cooling or fan from the HVAC equipment will satisfy the 1 to 60 minutes. If not, the
dehumidifier will turn on the HVAC blower to assure that the cycle time is met. For example: If
the home requires ventilation of 20 minutes every two hours set the CYCLE PERIOD Dip
Switch for 2 hours to ON and rotate the CYCLE TIME to 20 minutes. If the HVAC
equipment has only run for 10 minutes, the dehumidifier will turn on the HVAC blower
for 10 minutes at the end of the 2 hours to assure the ventilation / fan cycling time.
Finally, if using the Ventilation Damper, determine if the ventilation should be restricted based
on outdoor temperature. Set the VENT-AUTO / TIMED dip switch in VENT-AUTO (see Figure 15)
to prevent opening the ventilation damper if the outdoor air is above 100F, below 0F or except
with a heat call between 20F and 0F. In the timed setting the ventilation damper is activated
regardless of outdoor conditions. Note: The Outdoor Temperature Sensor (Model 8052) must be
installed for this to work.
You can also check the wiring of the dehumidifier to the HVAC equipment. If you rotate the
CYCLE TIME potentiometer to TEST, the HVAC blower should come on and the Ventilation
Damper (if equipped) should open. DO NOT leave the CYCLE TIME in TEST.
10
FIGURE 12
THERMOSTAT HVAC EQUIPMENT
R
C
G
W
Y
90-781A
OPTIONAL
VENTILATION
DAMPER
24 VAC
(10 VA min)
TRANSFORMER
R
C
WIRE NUT
G
W
Y
OPTIONAL
OUTDOOR
TEMPERATURE
SENSOR
(Model 8052)
FIGURE 13
CYCLE PERIOD
FIGURE 14
0
MIN
OFF
CYCLE TIME
FIGURE 15
SYSTEM SETUP
REMOTE-OFF
BLOWER-OFF
HOUSE
VENT-AUTO
DEHUMIDIFIER
CONTROL
(shown set
to 1 hour)
30 MIN.
1 HOUR
2 HOUR
3 HOUR
90-783C
(shown set to
30 minutes)
30
MIN.
60
MIN. MIN.
TEST
90-783C
ON
REMOTE
BLOWER
LOCAL
TIMED
90-783C