Scholar V VAIVA Maintenance & Service Manual 10/2017 Rev.2
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a. Condenser Minimum Temperature (°F)
: This is the minimum condenser tempera-
ture for satisfactory operation of the unit.
b. On/OFF Differential (°F)
: This is the separation between the ON temperature and
OFF temperature of one blower or the other.
c. Stage Differential (°F)
: This is the difference between the OFF point of Blower #1
and Blower #2.
d. Forward
: Press once to go to the next screen.
e. Back
: Press once to go to the previous screen
f. Back to Main
: Press once to go back to Main Screen
12. SCREEN 12: Heating Compressor Speed
(Changes require username/password)
There are two ways to control the speed of the compressor during space heating.
Fixed Heating Max
: with this method, the maximum speed of the compressor is fixed by
applying a fixed DC voltage to the compressor controller. Even if the ambient temperature is
high, if Fixed is chosen, the compressor will ramp up to the maximum speed associated with
the Heating Max Volts.
Linear Heating Max
: With this method, the maximum speed of the compressor is calculated,
based on the outdoor ambient. A calculation is made in the PLC and in cold weather, the
compressor control voltage is higher than in warmer weather. The endpoints of this control
curve can be set. High ambient applies to temperatures >= 70°F. Low ambient applies to
temperatures <= 30°F. Between these values the temperature varies linearly.
a. Fixed Max Heating Speed:
Press this once to set the max heating speed to a
fixed constant.
b. Linear Max Heating Speed:
Press this once to set the max heating speed to be a
function of the outdoor ambient.
c. Back
: Press once to go to the previous screen
d. Back to Main
: Press once to go back to Main Screen
The actual ambient temperature is shown, as well as the associated linear heating compressor
voltage. When in the Linear control mode, a small letter “L” is shown at the top of the Home
Screen.
