Alarm Tests for UV Systems

Proposal : Cryptosporidum inactivation requirements should also incorporate a test of the alarm on the UV system to ensure it will consistently activate if the UV transmittance drops below the UV set point.

Suggestion from CA DPH and CDC representatives on NSF Council of Public Health Consultants.

Proposed that NSF 50 require activation of the alarm 100 times without fail, at the UV Intensity set point at the maximum flow rate as determined in the crypto inactivation tests.

Test conducted by either:– decreasing UV transmittance of the water, or– reducing lamp power.

Life Tests for UV Systems

Currently life test requirements Sec 13.4 require testing at 39 +/- 1°C.

All UV system life tests observed to date have involved software issues, electronic issues or failure of a wiper mechanism. None are thought to have been caused by 39°C water, and likely would have occurred if the test was done at 20°C.

Proposal:All tests should be carried out at 39+/-1°C (102+/-2 °F) for spas or hot tubs typical operating temperatures for pools and spas 18 to 40°C (65 to 104°F).

Cleaning Requirements for UV Systems

Currently cleaning requirements of Section 13.5.

For systems utilizing quartz sleeves to separate the water passing through the chamber from the UV source, the system shall be designed to permit cleaning of lamp jackets and the sensor window or lens without mechanical disassembly. All piping for in-place cleaning purposes shall be entirely independent of the water piping system in and out of the unit, and a drain shall be provided. The chamber shall be designed so that at least one end can be dismantled for general and physical cleaning.For systems utilizing PTFE surface materials to separate the water passing through the UV chamber from the UV lamps, the unit shall be designed to be readily accessible to the interior and exterior of the PTFE. The unit shall be designed to permit the use of physical or chemical cleaning methods.

Cleaning Requirements for UV Systems

Questions we have had:

• What is mechanical disassembly and how does it differ from one end that needs to be dismantled?

• What PTFE components are being referred to?

• Are wipers allowed?

NSF Interpretation: Intent is to allow for mechanical cleaning systems (e.g. wipers) or for in-place chemical cleaning method that contains provisions to prevent the introduction of cleaning chemicals into the pool.

Cleaning Requirements for UV Systems

NSF Proposal:

All systems shall include either a mechanical cleaning system (such as a wiper system) or an in-place chemical cleaning method that contains provisions for preventing the introduction of cleaning chemicals into the pool or spa water.