161
ORP High Alarm
This error message indicates the ORP reading exceeds the user-programmed maximum allowable
value.
Possible
Causes
Corrective
Actions
The programmed value is too close to the
Go to the ORP Input Page and make sure
ORP set point.
that the High Alarm Limit is more than 50 mV
above the set point plus the dead band.
Slow ORP electrode response, dirty
Clean and calibrate the ORP electrode as
electrode.
described in Section 7.4 above. If the
calibration fails, refer to the ORP Calibration
Failure troubleshooting above.
Control direction set incorrectly.
For oxidizer feed the control direction should
be “force higher”, for reducer “force lower”.
Go to the ORP Output Page and make sure that
the correct control direction is selected.
Control device set at too high a flow rate.
Reduce the flow rate of the control device.
Chemical supply empty.
Replenish chemical supply.
Metering pump is siphoning.
Repair or install an anti-siphon valve.
If a brominator, solenoid valve is stuck open.
Repair or replace the solenoid valve.
The ORP dead band is set too high.
Go to the ORP Output Page and change the
dead band to be as low as possible to prevent
the ORP relay from chattering. If the ORP
reading fluctuates by +/- 2 mVs, then a dead
band of 5 mV is sufficient.
Faulty control device wiring.
Correct wiring.
ORP output relay is stuck closed.
Replace the relay board.
Blown fuse.
Replace fuse (F2 or F3).