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RED LIGHT CODES
Number of
Flashes
Controller Status
Description
3 Blinks
Sensor Fault
This fault can be caused by:
• Disconnected sensor. Disconnect sensor from sensor cable connector
and reconnect to ensure a good connection.
• Disconnected sensor cable lead inside the controller. Check for loose
wires where the sensor cable connects to the circuit board by tugging
on each wire.
• Broken wire in the sensor cable.
• Miswired sensor cable. Check that the wires are connected to the cor-
rect terminals on the control terminal block. Connect terminal 7 (24VDC
SUPPLY) to the Brown wire. Connect terminal 6 (TRANSDUCER INPUT)
to the White wire. Connect the Drain wire to the chassis.
• Vacuum in the system. A vacuum condition may exist in the system pip-
ing. Remove the sensor from the piping to release the vacuum.
• Failed sensor. To diagnose this failure a meter capable of reading mil-
liamperes (mA) and DC voltage (VDC) is required.
- Set the meter to read DC voltage (VDC)
- Place the black lead on terminal 5 (COM) and the red lead on terminal
7 (24VDC SUPPLY)
- If functioning properly, the DC voltage will be 24VDC +/- 15%. If this
voltage is not present, disconnect all control terminals and repeat the
measurement. If voltage does not recover, replace controller.
- Disconnect the White wire in the sensor cable from terminal 6.
- Set the meter to read DC current (mA)
- Connect the black lead from the meter to terminal 6 (TRANSDUCER
INPUT)
- Connect the red lead from the meter to the White wire in the sensor
cable.
- The meter will display the output of the sensor. If functioning properly,
the output of the sensor will be between 4mA and 20mA depending
on the pressure in the system. Refer to the chart below to determine
the sensor feedback at various pressures.
The following formula gives the transducer output based on applied
pressure:
Output Current =
Output Current Range
x System Pressure + 4mA
Pressure Range
TROUBLESHOOTING
