Humiditrol ® Enhanced Dehum. Accessory (Eda) - Lennox ComfortSense L7742U Programming Manual

NOTE − The D terminal is ALWAYS activated (24VAC)
when the thermostat is in HEAT or OFF mode; it is only in-
active (0VAC − reverse logic) during dehumidification.
Dehumidification adjustment will change the relative hu-
midity (RH) setting between 45 to 60% RH (default setting
is 50% RH). The lower the number, the more humidity will
be removed from the air.
HUMIDITY SETTING default OFF.
Installer settings must be turned on before the user
will have control over the humidity.
The mode selected determines how the user can adjust
the relative humidity (RH). The installer settings include
BASIC, PRECISION, HUMIDITROL, and OFF.
Dehumidification Modes
In BASIC mode, dehumidification occurs if these condi-
tions are met and signals are present at specific terminals:
S
dehumidification has been enabled on installer set-
tings, and
S
the unit is in COOL mode, and
S
dehumidification demand exists (RH above setpoint),
and
S
cooling demand exists (Y1 energized).
In PRECISION mode, dehumidification occurs if all BASIC
conditions are true, except cooling demand may or may
not be present. Maximum over cool from cooling set point
is 2ºF.
HUMIDITROL mode requires:
S
outdoor sensor must be installed and setup
S
dehumidification has been enabled on installer set-
tings, and
S
the unit is in COOL mode, (or if in AUTO, there has
been at least one thermostat cooling call made prior to
the dehumidification demand), and
S
a dehumidification demand exists (RH above set-
point), and
S
outdoor temperature is below 95°F, and
S
indoor temperature is above 65°F, and
S
the room temperature meets Humiditrol adjustment
parameters as follows:
MAX adj. − Indoor temp > 2°F above heating set-
D
point
MID adj. − Indoor temp >
D
MIN adj. − Indoor temp > 2°F below cooling set-
D
point
Scroll to HUMIDITY SETTINGS; press ENTER. Press the
box below DEHUMIDIFY.
HUMIDITY SETTINGS
HUMIDIFY DEHUMIDIFY
| |
Use up/down arrows to scroll to BASIC or PRECISION;
press ENTER.
DEHUM MODE SETTING
DEF(OFF) PRECISION
506180−01 09/08
HEAT SETPOINT+COOL SETPOINT
2
Page 12
Default setting is 50% RH. Use up/down arrows to change
the %RH; press SAVE.
DEHUM SETPOINT
DEFAULT (5O%) 45%
USER SETTINGS
BASIC, PRECISION, HUMIDITROL if set up by the in-
staller settings for BASIC, PRECISION or HUMIDITROL,
this adjustment controls the relative humidity (RH) be-
tween 45 and 60% (default 50%).
Scroll to HUMIDITY SETTINGS; press ENTER. Press the
box below DEHUMIDIFY.
HUMIDITY SETTINGS
HUMIDIFY DEHUMIDIFY
| |
Use up/down arrows to change the humidity setpoint (be-
tween 45 and 60%); press SAVE.
DEHUM SETPOINT 5O%
DEFAULT (5O%) 45%
OFF if OFF selected in installer settings for both humidify
and dehumidify, this message appears when HUMIDITY
SETTING is pressed:
HUMIDITY MODES OFF
If OFF is selected by the installer settings for DEHUMID-
IFY but HUMIDIFY is on, the humidification menu appears
(this setpoint adjust has NO effect on dehumidification):
HUM SETPOINT 45%
DEFAULT (45%) 4O%
®
Humiditrol Enhanced Dehumidification
Accessory (EDA)
®
If a Humiditrol EDA is present in the equipment at hand,
then the ComfortSenset Model L7742U thermostat must
be configured to properly operate the Humiditrol
follows (see Figure 16 [Page 18] for the Humiditrol
operation flowchart):
From the OPTIONS screen, select INSTALLER SET-
TINGS. Scroll to HUMIDITY SETTINGS and press EN-
TER; select DEHUMIDIFY.
HUMIDITY SETTINGS
HUMIDIFY DEHUMIDIFY
| |
Scroll to HUMIDITROL and press ENTER.
DEHUM MODE SETTING
HUMIDITROL
Set the dehumidification setpoint; then press SAVE.
DEHUM SETPOINT 50%
DEFAULT (5O%) 45%
Check the HUMIDITY SETTINGS in user settings to con-
firm that the user has control of the dehumidification set-
ting.
The ComfortSenset 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.
ComfortSenset Model L7742U thermostat
operation with Humiditrol enabled
Cooling only Dehumidification will only occur if:
®
EDA as
®
EDA
®
accessory.
®