Part No. 37-7775005
09/2020 11-HD17D1-1C-EN 23
American Standard Silver 302 and 303 Touchscreen Thermostat
11.1 Averaging or Weighting Remote
Sensors
The thermostat will weight or average the temperature of the
indoor remote sensor with the local sensor in the thermostat for
each program period. The averaging will be active only when the
local sensor and the indoor remote sensor are both functional
and enabled in the Installer/Configuration menu.
When the thermostat is in the Set Schedule mode, the weight of
the indoor sensor will be shown in the current temperature digits
of the display. The weight will show as A2 (average and default),
H4 (high) or L1 (low). Pressing the and keys at the same
time will change the weight for the program period. The weight of
the thermostat sensor is fixed.
In normal operation of the thermostat, the current temperature
displayed will be the weighted average of the local sensor and
the remote sensor using the formula (local sensor weight x local
sensor temperature) + (remote sensor weight x remote sensor
temperature) / (local sensor remote sensor weight).
Example: Local sensor temperature is 80° and the remote
sensor is 70°.
If weight is selected H4, the averaged temperature of 72° will be
displayed.
(1 x 80) + (4 x 70) / 5 = 72°
If weight is selected A2, the average temperature of 73° will be
displayed.
(1 x 80) + (2 x 70) / 3 = 73.3°
If weight is selected L1, the average temperature of 75° will be
displayed.
(1 x 80) + (1 x 70) / 2 = 75°
The example shows that the weight selected would prioritize
the overall averaged temperature between the two sensors. The
high weight selection caused the remote sensor to have a higher
influence in the calculated temperature average than the local
sensor and the low weight selection caused the remote sensor
to have less influence.
11.2 Dual Fuel Temperature Setpoint
When the thermostat is configured for Heat Pump mode and
the Dual Fuel feature is selected on, the thermostat can monitor
the outside temperature using remote sensor F145-1378 or use
software logic to determine when to switch to gas heat and shut
down the compressor. This eliminates the need for a fossil fuel
kit.
The user selectable temperature is called the dual fuel
temperature setpoint, dF and is set in the Installer/Configuration
menu, items 33 or 34. With outdoor remote sensor installed
and enabled, the dual fuel temperature setpoint (menu item 33)
can be set to a temperature of -5° through 50°. When outdoor
remote sensor is not installed, a software logic based dual
fuel number (menu item 34) from 01 to 09 can be selected. A
higher temperature or dual fuel setting will provide a smaller
stage separation between the heat pump and Aux to give more
comfort. A lower temperature or number will provide a larger
stage separation for more economy.
After the dual fuel temperature setpoint is set and
is pressed,
a delay, Cd, can be set for compressor shutdown after the
auxiliary stage is energized. This delay can be set from 0
seconds to 99 seconds to minimize the time that the system
may blow cooler air until the alternate source of heat comes
on. Default setting for delay is 60. When setting the delay, if the
or keys are held depressed, the setpoint will increase or
decrease at the rate of one degree every half second for the first
three seconds and double the speed after three seconds.
11.3 Blower Balance Point for Heating
Requires DHM connection from thermostat to heat pump
system. Air to air heat pumps use a fast fan speed to circulate
warm air for first stage heating. As outdoor temperatures
drop, the heat pump produces less heat and a high fan speed
makes the air from the ducts feel cooler. Blower Balance Point
allows you to select an outdoor temperature to slow the fan
speed so the air from the duct feels warmer. Select an outdoor
temperature where the air from the ducts starts to feel cool
(Installer Configuration Menu item 37). When the outdoor
temperature drops to the selected temperature, the thermostat
will slow the fan speed so the outlet air feels warmer.