Manual 2100-695
Page
24 of 54
4. Press UP or DOWN keys to change the value to the
desired override speed.
5. The fan should now run at the selected speed. The
output can be verified by again referencing the
Fan
Speed
parameter.
NOTE:
If unit is operating at the time the fan override
is being enabled, adjustments must be made to
OV Speed
first before switching
Fan Override
on.
Due to design considerations of the condenser section
of the wall-mount unit, placement/clearance of the
motor/fan blade is critical to heat dispersal. Should a
change of motor or fan blade be necessary, see Figure
38 for proper clearance adjustment.
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 line transducer is also referred to
as the discharge pressure sensor.
The discharge 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
.
5. Verify the measurement displayed on screen is
accurate (see Figure 39).
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.
Troubleshooting the Liquid Pressure Transducer
0-650 psig
0-5v
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 40).
FIGURE 38
Fan Blade Setting
.75" (from the closest point on the fan blade)
Liquid Pressure Transducer Alarm
When the liquid line pressure 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.
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.
FIGURE 40
Voltage to Pressure:
Liquid Pressure Transducer
FIGURE 39
Adjusting Liquid Pressure Transducer Values
