thermital AF ACS 220 B, Operating And Installation Instructions

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ENGLISH
39
Legionella
Legionella is a bacteria present in any water system.
The proliferation of this bacteria depends on many factors and it finds the best conditions to survive between 20º C to
45º C. Country by country, there are some different local regulation about Legionella prevention but all of them require
to heat water over than 50ºC.
Anti legionella cycle is a special operation function performed by AF ACS. The goal of this function is to heat all water
buffer volume. In this way, all bacteria that may have been inside the buffer would be killed.
Anti legionella cycle can not be deactivated in order to avoid health issues for end users. The cycle procedure can not
be modified, neither.
Anti legionella cycle
The anti legionella cycle is closed by one of the following conditions:
a) if the water temperature is 50º C for 2 hours continuously.
b) if the water temperature is 55º C for 30 minutes continuously.
c) if the water temperature is 60º C for 2 minutes continuously.
If within 72 hours (3 days) none of the above conditions have bee satisfied, automatically the water set point is moved
up to 60ºC if lower to perform the cycle. The yellow LED is switched on.
If there are electrical elements connected, they can be used during anti legionella cycle.
During the cycle, if none of the above conditions is verified and, by water temperature trend analysis, the software
understands that there is not enough energy using only the heat pump, the first electrical element will be switched on
automatically. All the other electrical elements will be switched on every120’ checking temperature trend analysis up
to reach one of the three conditions and to close the cycle. If cycle is closed, all electric elements are switched off.
If after 4 hours none of the above conditions occurred, the cycle will be considered NOT closed, it will continue and
the yellow LED will flash with low frequency to alert the end user. For this reason, we warmly recommend to connect
electric back up during AF ACS installation (or to enable them in AF ACS tank).
NOTE: the legionella cycle is fundamental for the health and if the system is running, normally it is done just by the ther-
modynamic energy; however we cannot exclude that in some cases the energy of electrical heater elements located in-
side the tank are needed and this is the reason because we warmly suggest to connect at least one element. However
our company is not responsible if during the installation any electric heater element is connected to the AF ACS unit.
To activate / deactivate the Antilegionella cycle, from the configuration menu, quickly press BUTTON 9 until the only
YELLOW LED is flashing. Then wait a few seconds until all the 5 GREEN LEDs light up and press BUTTON 9 once
more. 3 consecutive beeps confirm the setting.
WARNING !
Power down the system before changing the settings.
SW1: SETTING OF ELECTRICAL BACKUP HEATERS
See section “ Use of electrical heater elements ”.
SW2: SETTING OF TANK VOLUME
Set SW2 in order to select the water volume of the tank:
OFF - OFF = 300 l ON - OFF = 220 l
SWITCHES SETTING (CONTROL BOARD)
FACTORY SETTING