Stage Delay And Differential Settings - Lennox ComfortSense L7742U Programming Manual

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 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
Heating only Thermostat will cycle heating ON" and
OFF to maintain heating setpoint. Dehumidification func-
tions are disabled.
Autochangeover Dehumidification will only occur if a
dehumidification demand is present, a cooling demand is
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 mode is allowed to overcool up to 2°F above
the heating setpoint.
Note: If the last thermostat demand was a heating de-
mand, the thermostat does not require a cooling demand
®
before Humiditrol operation.
Humidification Sensor Fault
If the humidification sensor fault occurs, then the H termi-
nal becomes inactive, and the D terminal goes to 24V.
NOTE − Dew point adjust is only available when an outdoor
sensor is attached.
®
Other Humiditrol EDA Notes:
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.
®
®
dehumidification is inhibited be-
Stage Delay & Differential Settings
(Installer settings)
Press OPTIONS tab, then use the scroll arrows to select
INSTALLER SETTINGS. Press ENTER.
INSTALLER SETTINGS
−−−−−−−−−−−−−−−−−−−−
The following stage delay and differential settings are
available for modifying. Follow the instructions for each pa-
rameter.
STAGE DELAY AND DIFFERENTIAL SETTINGS The
calls. differential or delay settings in the Installer Settings menu
are:
STG DELAY TIMERS
STG 1 DIFF
STG 2 DIFF
STG 2 DELAY
STG 3 DIFF
STG 3 DELAY
STG 4 DIFF
STG 4 DELAY
H/C STGS LOCKED IN
STG 2 HP LOCK TEMP
STG DELAY TIMERS default ON. When ON, all stage
delay timers (stages 2, 3, and 4) are enabled and will serve
to bring on additional stage(s) of cooling or heating on a
timed basis (default 20 minutes) in cases when the pre-
vious stage of heating or cooling will not raise or lower the
room temperature to the set point in a given time.
calls.
When OFF is selected all stage delay timers are disabled.
This means stages are changed based on the temperature
and not their timer delays. Scroll to STG DELAY TIMERS;
press ENTER.
STG DELAY TIMERS
DEFAULT (ON)
DIFFERENTIAL SETTINGS The differentials below and
shown in the figures 7 through 14 are defaults and are ad-
justable for different system setups.
STG 1 DIFF Stage 1 differential is used in all thermo-
stats. The default is 1.0°F but can be programmed be-
tween 0.5° and 8.0°F in 0.5°F increments.
Scroll to STG 1 DIFF; press ENTER. Select the desired
differential. Press SAVE.
STG 1 DIFF
DEFAULT(1.O°F)
STG 2 DIFF thru STG 4 DIFF (multistage models only).
The default is 1.0°F but can be programmed between 0.5°
and 8.0°F in 0.5°F increments.
Scroll to STG 2 DIFF (or 3 or 4); press ENTER. Select the
desired differential. Press SAVE.
STG 2 DIFF
DEFAULT(1.O°F)
2nd thru 4th STAGE DELAY timer (multistage models
only). If STG DELAY TIMERS is turned ON, the default
delay is 20 minutes but can be programmed from 5 to 120
minutes in 5−minute increments. If first stage fails to ad-
vance the ambient temperature toward the setpoint by
1.0°F in the programmed delay time, then the second
stage is activated.
Page 13
(not on single stage models)
(all models)
(2 stage models)
(not on single stage models OR if timers turned off)
(2−stage heat pumps w/backup heat)
(not on single stage models OR if timers turned off)
(2−stage heat pumps w 2−stages backup heat)
(not on single stage models OR if timers turned off)
OFF
O.5°F
O.5°F
ComfortSenset Model L7742U Touch Screen
7−Day Programmable Thermostat