A low UV output alarm can only be displayed if a UV sensor is installed in a UV system. Many different factors can cause the UV intensity reading to be low when a UV sensor is installed. If low UV intensity is detected, one of the following screens will be displayed.
When determining the cause of a UV alarm, the first step is to perform a water quality test. It is important that water quality parameters fall within the specifications below.
Hardness: <7 gpg (120 mg/L)
Iron (Fe): <0.3 ppm (0.3 mg/L)
Manganese (Mn): <0.05 ppm (0.05 mg/L)
Turbidity: < 1 NTU
Tannins (organics): <0.1 ppm (0.1 mg/L)
UVT (transmittance): >85%
If the water quality falls outside the requirements, pre-filtration must be installed to resolve the issue. If the water quality falls within the requirements above, a dry test should be performed following the directions below.
Dry Test Procedure
- Shut off the water source.
- Unplug the controller from the power source.
- De-pressurize the chamber and drain water.
- Clean and dry the sensor and reinstall. How to Clean a UV Sensor
- Clean and dry the quartz sleeve and reinstall. How to Clean a Quartz Sleeve
- With the water still shut-off, plug the controller into the power source.
- Check the UV intensity. If 100%, the UV sensor is operating normally.
If the dry test shows a good result, other possible causes of low UV alarms are:
- Air bubbles in water.
- This can be tested by taking a water sample after the UV system in a clear glass. Look to see if bubbles form. If they do, there are air bubbles in the water. This must be purged from the water supply before the UV system.
- High water temperatures.
- This is seen when water is not flowing through the chamber for long periods of time. A flowmeter or a temperature relief valve can be installed to mitigate this issue.
If the UV sensor is displaying a low UV intensity during a dry test, or if the cause for the alarm is undetermined after troubleshooting, please submit a ticket for support. New Ticket