Reznor R8HE Unit Installation Manual - Manual (Page 14)

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air-flow. Verify the selected rise is within the specification
shown on the furnace rating label or in the tables.
Dehumidification Options
The fixed speed motor control board has a DEHUM
connection that allows the system to increase the amount
of humidity that is removed from the circulating air. This
is accomplished by reducing the CFM and allowing the
cooling coil to become colder. This function is only available
when there is a call for cooling. There are many ways this
function can be electrically wired.
When 24VAC is present at the
DEHUM terminal of the
blower control board the airflow requirements will be
reduced to approximately 75% of the nominal airflow
requirements. If the humidity level of the conditioned space
decreases during the cycle and the humidistat opens, the
airflow will be restored to 100% of the selected value.
• If the room thermostat incorporates a humidity sensor
and DEHUM output, connect the DEHUM on the
thermostat to the DEHUM terminal on the motor control
board. See Figure 10 (page 36) .
• If using a separate humidistat, connect the DEHUM & R
terminals on the humidistat to the DEHUM & R terminals
on the motor control board. In this option, the DEHUM
output of the humidistat must be set to be normally open
and closed when there is a call for dehumidification.
If a humidistat is not available, it is an acceptable option
to directly jumper the R & DEHUM on the blower control
board. NOTE: This option will always operate the blower
at 75% the rated airflow for the first 10 minutes of every
cooling cycle no matter what the humidity level of the
home is. See
Figure 10 .
CAUTION:
To avoid personal injury or property damage,
make sure the motor leads do not come into
contact with any uninsulated metal components
of the unit.
O p t i o n a l F u r n a c e C o n t r o l B o a r d
Connections
Electronic Air Cleaner
The furnace control board provides output terminals
for an optional electronic air cleaner (EAC) that can be
installed in the return air duct of your system. The EAC
output is energized any time the HEAT or COOL blower
speed is energized. Control ratings are 1.0 Amp. @ 240
VAC. Output connections are made via board terminals
labeled EAC and NEUTRAL.
Humidifier
The furnace control board provides output terminals for
an optional humidifier ( HUM) that can be installed on
your system. The HUM output is energized any time the
furnace inducer motor is energized. Control ratings are
1.0 Amp. @ 240 VAC. Output connections are made via
board terminals labeled HUM and NEUTRAL.
Check all factory wiring to the proper unit wiring diagram:
Figure 13 (page 37) , Figure 14 (page 38) , & Figure 15
(page 39) . Inspect the factory wiring connections and
make sure they didn’t loosen during shipping or installation.