Instruction manual

102
8.0 TROUBLESHOOTING
8.1 ERROR MESSAGES
No Flow
This error message occurs when the input signal to the flow switch terminals is open
(disconnected). When sample flow past the flow switch is sufficient, the switch should be closed.
All control outputs will be forced off until the flow signal returns.
Possible Causes Corrective Actions
Valve is closed. Open valve to restore sample flow.
Y Strainer is plugged. Clean Y strainer.
Circulation pump has stopped. If this is not normal, repair circulation pump.
Insufficient pressure differential. Ensure that the sample piping is tapped into the
discharge side of the circulation pump, and flows to
either atmospheric pressure (the cooling tower sump)
or the suction side of the circulation pump.
Flow switch wires disconnected. Reconnect wires.
Faulty flow switch housing assembly Replace the flow switch housing assembly.
(p/n 190998).
Faulty sensor interface board. Replace the sensor interface board.
Conductivity Calibration Failure
This error message occurs after calibration of the conductivity sensor. A clean sensor should give a
predictable signal in a solution of known conductivity. If the calibration adjusts the signal more
than 50% away from the predicted value, the calibration will fail. A signal this far off indicates a
problem with the reading, and is not normal.
Possible Causes Corrective Actions
Dirty sensor. Clean sensor as described in Section 6.2 above.
Sensor cable disconnected. Reconnect cable.
Problem with hand-held instrument Refer to the troubleshooting guide for the hand held
instrument used to determine the system conductivity.
Faulty sensor. Replace sensor.
Faulty sensor interface circuit board Replace the sensor interface board.
(if system conductivity).
Faulty sensor option circuit board Replace the sensor option board.
(if makeup conductivity).