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Scholar V VAIVA Maintenance & Service Manual 10/2017 Rev.2
4. SCREEN 4:
Differentials and Deadbands
(Changes require username/password)
a. High/Low Deadband Diff (°F)
: This is a number added to and subtracted from a
set-point to form a control band. For example, if the setpoint is 75°F and the High/
Low Deadband Diff is .25, the control band would be from 74.75°F to 75.25 °F.
b. Shutoff Differential (°F)
: In cooling, this is a differential applied to the low end
of the control band to set the point where the compressor turns off. For example,
if the control band is from 74.75 °F to 75.25°F and the shutoff differential is 1.5
°F, the compressor would turn off when the temperature reached 73.25 °F (74.75
minus 1.5). In heating, the differential is applied to the high end of the control band.
c. Hot Gas Reheat Diff (°F)
: In the dehumidification mode, the hot gas reheat valve
is controlled by a thermocouple located in the supply air stream. Based on the
temperature of the supply air, during dehumidification when there is not a call for
cooling, the hot gas reheat valve is turned on to heat the air back up to the set
point. The Hot gas Reheat Diff is applied to the cooling set point to establish a
temperature where the hot gas valve is energized and de-energized. For example,
if the cooling set point is 75ׄ°F and the Hot Gas Reheat differential is 1°F, the hot
gas valve turns on when the temperature is 74°F (75° - 1°) and turns off when the
temperature is 76°F (75° + 1°).
d. Electric Heat Diff (°F)
: This differential is applied to the heating set point to
determine the temperature at which the resistance heat is turned on and off. For
example, if the heating set point is 65° and the Electric Heat Diff is 1.5°, the heater
will turn on at 63.5°F (65° - 1.5°) and will turn off at 66.5°F (65° + 1.5°).
e. De-humidify Differential (%)
: This differential is applied to the relative humid-
ity set point to establish at what point de-humidification will start and stop. For
example, if the relative humidity set point is 50% and the De-humidify Differential
is 1%, dehumidification will be enabled at 51% (50% + 1%) and disabled at 49%
(50% - 1%).
f. Forward
: Press once to go to the next screen.
g. Back
: Press once to go to the previous screen
h. Back to Main
: Press once to go back to Main Screen
