Instruction manual

110
pH High Alarm
This error message indicates the pH reading exceeds the user-programmed maximum allowable
value.
Possible Causes Corrective Actions
The programmed value is too close to Go to the pH Input Page and make sure that the
pH set point. the High Alarm Limit is set at least 0.5 pH
units above the set point.
Assuming you are feeding acid:
Chemical supply empty. Replenish chemical supply.
Faulty pH electrode. Clean and calibrate the electrode as described
in Section 7.3 above. If the calibration fails,
see troubleshooting for pH Calibration Failure
above.
Control direction set incorrectly. For acid feed the control direction should be
“force lower”. Go to the pH Output Page and
verify the correct setting.
Faulty metering pump. Repair or replace the metering pump.
Blown fuse. Replace the fuse (F2).
Faulty metering pump wiring. Correct the metering pump wiring.
Faulty pH output relay. Replace the relay interface board.
pH Low Alarm
This error message indicates the pH reading is below the user-programmed minimum allowable
value.
Possible Causes Corrective Actions
Assuming you are feeding acid:
The programmed value is too close to Go to the pH Input page and make sure that the
pH set point. the Low Alarm Limit is set for at least 0.5 pH
units below the set point minus the dead band.
Slow pH electrode response, dirty electrode. Clean and calibrate the pH electrode as
described in Section 7.3 above. If the
calibration fails, see troubleshooting for pH
Calibration Failure above.
Metering pump set at too high a flow rate. Reduce the flow rate of the metering pump.
Metering pump is siphoning. Install or repair the anti-siphon valve.