UV Water Sterilizer Shows a Low-Intensity Alarm

Verify flow and water transmittance, then inspect quartz-sleeve fouling, lamp age, sensor cleanliness, temperature, power supply and calibration. Never assume a lit lamp is delivering the required germicidal output.

Use the plant chemical-handling procedure, suitable PPE and lockout/tagout. Depressurize housings and verify that cleaning chemicals have been displaced before opening a pump, filter or membrane vessel.

Locate the fault

• UV intensity falls gradually during service
• Alarm appears immediately after lamp replacement
• Reading drops only at high water flow
• Quartz sleeves show mineral or organic film

Inspection sequence

1. Place water on hold or divert it according to the validated disinfection plan
2. Record flow, intensity, lamp hours, temperature and upstream water quality
3. Measure UV transmittance with the approved method if available
4. Inspect and clean sleeves and sensor window using the specified chemical and handling procedure
5. Verify lamp part number, seating, connector and warm-up condition
6. Check sensor calibration and ballast or power diagnostics with qualified personnel

Corrective work

• Clean or replace sleeves and damaged seals
• Install the specified lamp and reset hours only after actual replacement
• Correct upstream iron, turbidity or organic breakthrough and reduce flow only within validated limits
• Repair or calibrate the sensor, ballast or power supply

Operating records and follow-up

• Trend UV intensity with flow and transmittance
• Replace lamps by validated output or service interval
• Control hardness and iron ahead of UV
• Inspect sleeves before alarms become critical
• Test alarm and diversion interlocks

Equipment details: Water Treatment Machine Purification System.