Siemens RVL471 - Page 82

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Siemens Building Technologies Basic Documentation RVL471 CE1P2524E
HVAC Products 23 Function block "Legionella function" 23.10.2002
When the periodicity and time criteria are satisfied, the legionella function will be re-
leased. Release of the legionella function means that the d.h.w. temperature setpoint
will be raised to the legionella setpoint and forced charging is enabled. If d.h.w. heating
is switched off or the holiday function or operating mode changeover active, the legion-
ella function will be released, but not the setpoint boost. On termination of the overrid-
ing function, d.h.w. heating to the legionella setpoint will again be triggered since the
legionella function is still released.
The behavior of the legionella function as a function of the d.h.w. temperature is as
follows:
T
BWw
T
BWw
- SD
BW
T
BWw
- SD
BW
- 2K
T
BWx
ON
OFF
ON
OFF
ON
OFF
T
BWx
t
2526D03
TBWx D.h.w. temperature
TBWw D.h.w temperature setpoint
SDBW Switching differential of d.h.w. charging
t
Time
If a maximum d.h.w. charging time is set, it also acts here. If the legionella setpoint is
not reached, the legionella function is interrupted and resumed at the end of the maxi-
mum charging time.
Start timer
dwelling time
Reset timer
dwelling time
Circulating pump
Forced charging
Release of legion-
ella function
Start conditions for legionella function satisfied
Timer dwelling
time elapsed
Start Timer
Verweildauer
Start timer
dwelling time