10
A. Set the 1/2, 1, 2 or 3 hour period by setting the CYCLE PERIOD dip switches (
Figure 13
) to
determine how often the dehumidifier should look to cycle the HVAC fan. The factory default
setting is 1 hour.
B. The CYCLE TIME dial determines how long during every Cycle Period the HVAC fan should
operate. Adjust the dial from OFF to between 1 and 60 minutes. This will give you HVAC fan
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 often satisfy the run time requirement. If not, the dehumidifier will
turn on the HVAC fan to assure that the Cycle Time is met.
For example: If the building
requires air cycling of 20 minutes every two hours set the CYCLE PERIOD Dip Switch
for 2 hours to ON, turn OFF the 1 HOUR Dip Switch 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 fan for 10 minutes at the end of the 2 hours to assure the fan cycling time.
FIGURE 14
90-783C
FIGURE 13
O
N
1
2
3
4
2 HOUR
3 HOUR
30 MIN.
1 HOUR
CYCLE PERIOD
90-783C
CYCLE TIME
TEST
60
MIN.
OFF
0
MIN
MIN.
30
MIN.
(shown set
to 1 hour)
FIGURE 15
4
3
2
1
O
N
VENT-TIMED
HVAC FAN
SYSTEM SETUP
ON
B
CONVERTIBLE
HVAC FAN
WHL HOUSE
VENT-AUTO
A
OFF
90-969
(shown set to
30 minutes)
VENTILATION / AIR CYCLING SETTINGS
The Aprilaire Dehumidifier has the option
to monitor HVAC heating, cooling and fan
calls to assure the HVAC fan 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 an outdoor 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 Model
70 Occupied 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.
HVAC EQUIPMENT
THERMOSTAT
WIRE NUT
DEHUMIDIFIER
CONTROL
24 VAC
(10 VA min)
TRANSFORMER
DAMPER
VENTILATION
OPTIONAL
G
R
C
G
W
Y
Y
W
C
R
A
+
B
D
E
H
R
E
M
O
T
E
H
V
A
C
E
Q
U
IP
.
V
E
N
T
C
f
G
s
G
h
W
-
Y
R
f
D
A
M
P
E
R
S
OPTIONAL OUTDOOR
TEMPERATURE SENSOR
(Model 8052)
S
E
N
S
O
R
O
D
T
S
W
IT
C
H
FL
O
A
T
FIGURE 12
90-968
A. If using the Ventilation Damper, determine if the ventilation should be restricted based on
outdoor temperature. Set the VENT-AUTO / VENT-TIMED dip switch to VENT-AUTO
(see
Figure 15
) to prevent opening the ventilation damper if the outdoor air is above 100°F,
below 0°F or except with a heat call between 20°F and 0°F. In the VENT-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.
AIR CYCLING
OUTSIDE AIR VENTILATION
