Humiditrol ® Enhanced Dehumidification Accy - Lennox ComfortSense 7000 Series Programming And Application Manual

Dehumidification
(continued)
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Humiditrol Enhanced Dehumidification Acces-
sory
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If a Humiditrol EDA is present in the equipment at hand,
®
then the ComfortSense
be configured to properly operate the Humiditrol
follows (see Figure 15 [Page 22] for the Humiditrol
operation flowchart):
From the OPTIONS screen, select INSTALLER SET-
TINGS. Scroll to HUMIDITY SETTINGS and press EN-
TER; select DEHUMIDIFY.
HUMIDITY MODE
HUMIDIFY DEHUMIDIFY
| |
Scroll to HUMIDITROL and press ENTER.
DEHUM MODE SETTING
DEF(OFF) HUMIDITROL
Set the dehumidification setpoint; then press SAVE.
DEHUM SETPOINT
DEFAULT (5O%) 45%
Check the HUMIDITY SETTINGS in user settings to con-
firm that the user has control of the dehumidification set-
ting.
®
The ComfortSense Model L7742U thermostat is now
configured to operate the Humiditrol
®
NOTE − Humiditrol EDA operation requires use of an out-
door sensor. If sensor is not connected and Humiditrol
EDA is enabled, OUTDOOR SENSOR REQUIRED" is
displayed in the information display.
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ComfortSense Model L7742U thermostat
operation with Humiditrol enabled
Cooling only Dehumidification will only occur if:
S
a dehumidification demand is present,
S
a cooling demand is not present,
S
outdoor temperature is less than 95ºF,
S
indoor temperature is not cooler than 65ºF or cooler
than the heating setpoint + 2ºF (IF the difference be-
tween cooling and heating setpoints is greater than the
deadband).
In this case, 24 VAC is removed from the D" terminal and
Y1 & Y2" terminal (if available) becomes activated with
24VAC. This cycles the indoor variable speed motor to the
dehumidification speed and cycle Y2 ON" to the outdoor
unit. Cooling has priority over Humiditrol
506230−01 05/09
Model L7742U thermostat must
®
EDA as
®
accessory.
®
calls.
Heating only Thermostat will cycle heating ON" and
OFF to maintain heating setpoint. Dehumidification func-
tions are disabled.
Autochangeover
dehumidification demand is present, a cooling demand is
®
EDA
not present, outdoor temperature is less than 95°F, indoor
temperature is above 65°F and the indoor temperature is
not cooler than 2ºF above heating setpoint.
In this case, the 24 VAC is removed from the D" terminal
and the Y1 & Y2" terminal (if available) becomes activated
with 24VAC. This will cycle the indoor variable speed motor
to the dehumidification speed and cycle Y2 ON" to the out-
door unit. Cooling calls have priority over Humiditrol
®
Humiditrol
the heating setpoint.
Note: If the last thermostat demand was a heating de-
mand, the thermostat does not require a cooling demand
before Humiditrol
Humidification Sensor Fault
If the humidification sensor fault occurs, then the H termi-
nal becomes inactive, and the D terminal goes to 24V.
Dew point adjust is only available when an outdoor sensor
® is attached.
Other Humiditrol
If the outdoor sensor is disconnected while HUMIDITROL
is enabled, the thermostat will not allow operation in dehu-
midification mode.
Set point range: 45 to 60% Relative Humidity (RH). Facto-
ry default − 50%.
Relative Humidity controls to within 2% on either side of
RH set point.
When the D" terminal is activated with 24VAC, dehumidifi-
cation is inactive.
BASIC, PRECISION and HUMIDITROL modes are deac-
tivated by default from the factory.
As a precaution, regardless of how low the heating setpoint
has been set, Humiditrol
low 65ºF indoor temperature.
Page 16
Dehumidification will only occur if a
mode is allowed to overcool up to 2°F above
®
operation.
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EDA Notes:
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dehumidification is inhibited be-
®
calls.