nvent Raychem HWAT-ECO V4, Руководство пользователя

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5.3 Legionella prevention
The growth of legionella pneumophila is dependent on temperature:
HWAT-R and HWAT-ECO offer the possibility of increasing the water
temperature by fully powering the HWAT-R. The increased water
temperature enables decontamination (measures anti-scalding are
essential). Most legionella pneumophila bacteria are killed at 60°C over a
period of 30 minutes.
Warning: The selected pipework material should be able to resist the
decontamination temperature.
The graphs on page 27 and 28 indicate the time needed for the heat-
up of the warm water to a desired decontamination temperature with
HWAT-R heater
Notes:
• The graphs are theoretically calculated. A safety margin should be
taken into account based on the condition of the pipework, e.g. lime.
• The heat-up times are valid after ageing of the HWAT-R heater.
The HWAT-R heater achieves specified power after ±1 month of full
operation.
Calculation steps of heat-up time for legionella prevention:
1. Select the appropriate graph based on average pipe diameter and
used insulation thickness
2. Read the required heat-up time between maintain temperature and
60°C = ∆T
3. Increase heat-up time by 30 minutes for legionella destruction
4. Ensure that the previous block is at maintain temperature of minimum
50°C (otherwise heat-up time will be too long)
Total heat-up time for programming = ∆T + 30 minutes
Note: the cool-down time till maintain temperature takes ± equal time.
Take necessary measures to prevent scalding. Legionella prevention
during night is recommended.
Example:
1. Select graph for 1” pipe Stainless Steel (SS), 30 mm Rock Wool (RW)
insulation
2. ∆T from 55°C to 60°C = 45 min.
3. Total = 45 min. + 30 min. = 75 min. heat-up cycle