Manual 2100-670B
Page
10 of 33
FIGURE 6
Adjusting Return Air Sensor
2. Press UP or DOWN keys and ENTER key to enter
TECHNICIAN password 1313.
3. Press UP or DOWN keys to scroll to
I/O Config
;
press ENTER key.
4. Press UP or DOWN keys to scroll to
Return Air
Sensor (C5)
; press ENTER key.
5. Verify the measurement displayed on screen is
accurate (see Figure 6).
6. If the measurement needs to be adjusted, apply an
offset value by pressing ENTER to scroll to
Offset
.
7. Press UP or DOWN keys to adjust the offset.
8. The update will not take effect until the cursor is
moved out of the
Offset
parameter.
9. Once adjusted, press the ESCAPE key several
times to return to Main Menu screen.
Return Air Temperature Alarm
When the return air temperature sensor value is out of
range (-41.0 to 303.0°F), the controller will generate
a sensor failure alarm to indicate the sensor is not
working properly.
This alarm is fixed and cannot be adjusted.
Temperature/Humidity Control Operation
The unit utilizes a PID control loop for space control.
This control will compare the space temperature to
the space setpoint. Based on how far away from the
setpoint the temperature is, the loop will output a
cooling or heating capacity number between 0 and
100%. The unit will then take all of the available
cooling methods and distribute them evenly across the
0-100% range. The stages are then brought on as the
heating or cooling capacity reaches the percentage that
brings the stages on or off.
There are separate setpoints
for cooling and heating.
To change or view the unit setpoint:
1. From the Status screen, press UP or DOWN key
until Quick Menu displays Setpoints icon ( ).
Press ENTER key.
2. Press ENTER key to scroll to
Cool
Setpoint
or
Heat
Setpoint
(see Figure 4 on page 8).
3. Press UP or DOWN keys to change the value to
desired heating and/or cooling setpoint.
Cooling
The unit is equipped with 1 stage of freecooling and 2
stages of mechanical cooling (compressor and solenoid)
for a total of 3 cooling stages (see Figure 7).
FIGURE 7
Cooling w/Economizer
Deadband (sometimes called a neutral zone or dead zone) is an interval of a signal domain or band where no action occurs
Compressor Stage 1
Freecooling
10%
20%
30%
40%
50%
60%
70%
80% 90% 100%
Off
Deadband
On
-10%
0%
110% 120%
Compressor Stage 2
