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UV Intensity Sensor
Quarterly, and when indicated by the low UV intensity alarms, ensure that the intensity
sensor located on the top exterior of the UV chamber is clean and free of dirt or scaling.
Throughout normal operation, minerals in the water will slowly form a coating on the intensity
sensor window. This coating may not be visible and must be removed, because it reduces the
amount of UV light reaching the sensor, thereby giving a false indication of lower disinfection
performance. When disassembling any component of the UV system, the power to the system
must be disconnected and the Nexus basin must be fully drained. To clean or replace the
intensity sensor, follow the procedure below:
• Close the ball-valve in the UV System suction line.
• Remove the UV System Enclosure.
• Unscrew the intensity sensor from the top of the UV chamber.
• Clean the intensity sensor window with a cloth soaked in CLR, vinegar or some other mild
acid and then rinse with water.
• Reinstall the intensity sensor.
• Replace the UV system enclosure.
• Open the ball-valve in the UV System suction line.
• Verify the UV system is operating correctly by resuming normal unit operation. Alarms will
notify the user within 1 minute if there is a UV intensity or pump operation issue.
– If UV intensity or UV pumps alarms are activated, consult the troubleshooting section.
UV Intensity Sensor
Quarterly, ensure that the intensity sensor located on the top exterior of the UV chamber is clean and
free of dirt or scaling. Throughout normal operation, minerals in the water will slowly form a coating on
the intensity sensor window. This coating may not be visible and must be removed because it reduces
the amount of UV light reaching the sensor, thereby giving a false indication of lower disinfection
performance. When disassembling any component of the UV system, the power to the system must be
disconnected and the Nexus sump must be fully drained. To clean or replace the intensity sensor, follow
the procedure below:
•
Close the ball-valve in the UV System suction line.
•
Remove the UV System Enclosure.
•
Unscrew the intensity sensor from the top of the UV chamber.
•
Clean the intensity sensor window with a cloth soaked in CLR, vinegar or some other mild acid
and then rinse with water.
•
Reinstall the intensity sensor.
•
Replace the UV system enclosure.
•
Open the ball-valve in the UV System suction line.
•
Verify the UV system is operating correctly by resuming normal unit operation. Alarms will
notify the user within 1 minute if there is a UV intensity or pump operation issue.
o
If UV intensity or UV pumps alarms are activated, consult the troubleshooting section.
UV System Solenoid Drain Valve
The UV System solenoid drain valve should be inspected every six months. However, the interval
between cleanings will vary depending on water quality and service conditions. If the voltage to the
solenoid is correct, then sluggish valve operation, excessive noise, or leakage will indicate that cleaning
is required. The valve is normally open, but faulty valve operation may cause it to fail either open or
closed. For cleaning instructions,
Commented [CB3]:
Tera, use same picture as Figure 27,
with new figure number and caption “Drain Solenoid Valve”
UV System Solenoid Drain Valve
The UV System solenoid drain valve should be inspected every six months. However, the
interval between cleanings will vary depending on water quality and service conditions. If the
voltage to the solenoid is correct, then sluggish valve operation, excessive noise, or leakage will
indicate that cleaning is required. The valve is normally open, but faulty valve operation may
cause it to fail either open or closed.
Figure 40.
Drain Solenoid Valve
Figure 39.
Intensity Sensor Removal