Table of Contents
Advertisement
Liquid Line Pressure Transducer
The unit has a pressure transducer installed on the
liquid line between the condenser and electronic
expansion valve (EEV). The transducer is used for
system monitoring of the liquid 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 liquid pressure sensor 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 Liquid Pr
Sensor C9; press ENTER key.
5. Verify the measurement displayed on screen is
accurate (see Figure 36).
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, press the ESCAPE key several
times to return to Main Menu screen.
FIGURE 36
Adjusting Discharge/Liquid Transducer
Pressure Values
Troubleshooting the Discharge/Liquid Pressure
Transducer
0-650 psig
0-5vdc
4v/650 psig = .00615 volts per 1 psig
Example: 325 psig x .00615 + .5 v = 2.5 volts
Formula for Tech:
Measured Pressure x .00615 + Sensor Offset =
Expected Transducer Signal Voltage (see Figure 37).
Manual 2100-694B
Page
24 of 62
FIGURE 37
Voltage to Pressure:
Discharge/Liquid Pressure Transducer
Discharge/Liquid Pressure Transducer Alarm
When the discharge pressure transducer value is out
of range (0-650 PSIG), the controller will generate a
sensor failure alarm to indicate the transducer is not
working properly.
This alarm is fixed and cannot be adjusted.
Liquid 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 liquid 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 Liquid Temp
Sensor C2; press ENTER key.
5. Reference the Value to verify the temperature (see
Figure 38).
FIGURE 38
Adjusting Discharge/Liquid Temperature Input
Advertisement
Table of Contents
Troubleshooting
