Manual 2100-670
Page
19 of 32
High Pressure Transducer
The unit has a high side pressure transducer installed
on the liquid line between the condenser and electronic
expansion valve (EEV). The transducer is used for
system monitoring of high side system pressures.
This information is used to indicate when outdoor coil
cleaning is necessary based on outdoor conditions and
system pressures. The sensor is also used to adapt
the condenser fan speed for high and low ambient
conditions.
The high pressure input can be verified and adjusted by:
1. Press MENU key to go to the Main Menu screen.
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
Disch Pr
Sensor (C10)
; press ENTER key.
5. Verify the measurement displayed on screen is
accurate (see Figure 24).
6. If the measurement needs to be adjusted, apply an
offset value by pressing the ENTER key to scroll to
Offset
.
7. Press UP or DOWN keys to adjust the offset. The
update will not take effect until the cursor is
moved out of the offset parameter.
8. Once adjusted, the ESCAPE key several times to
return to Main Menu screen.
High Pressure Transducer Alarm
When the high pressure transducer sensor value is out
of range (0-650 PSIG), the controller will generate
a sensor failure alarm to indicate the sensor is not
working properly.
This alarm is fixed and cannot be adjusted.
Discharge Temperature Sensor
The unit is equipped with a liquid line temperature
sensor to monitor the temperature of the liquid
refrigerant leaving the condenser and entering the EEV.
The temperature is measured with a 10k ohm NTC
thermistor.
The discharge temperature sensor can be verified and
adjusted by:
1. Press MENU key to go to the Main Menu screen.
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
Disch Temp
Sensor (C3)
; press ENTER key.
5. Reference the
Value
to verify the temperature (see
Figure 25).
6. If an offset needs to be applied, press ENTER key
to scroll to
Offset
.
7. Press UP or DOWN keys to change the offset to
desired value.
8. Press ENTER key to save.
9. Press ESCAPE key several times to return to Main
Menu screen.
FIGURE 24
Adjusting High Pressure Input
FIGURE 25
Adjusting Discharge Temperature Input
Condenser Fan Operation
Condenser Fan Speed Control
The condenser fan motor maintains its high efficiency
across a wide operating range. The result is a
significant reduction in energy use when the motor is
run at reduced speeds. See Table 8 on page 20.
