Operation Of Circulating Pump; Maximum Limitation Of The Return Temperature; Mode Of Operation - Siemens RVD230 Basic Documentation

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If no dwelling time has been set (operating line 127 =
performed the moment the legionella setpoint is reached.
In the case of direct d.h.w. heating without circulating pump, the set value has no im-
pact (no dwelling time).

18.1.5 Operation of circulating pump

The circulating pump can be forced to run during the period of time the legionella func-
tion is active. This ensures that hot water also circulates through the plant's hot water
distribution system. Entry (0 or 1) is made on operating line 128.
If the storage tank temperature exceeds the legionella setpoint minus 1 K, the circulat-
ing pump will be forced to run.
If the storage tank temperature falls below the legionella setpoint by more than
SD + 2 K (switching differential plus 2 K), the circulating pump will no longer be acti-
vated.

18.1.6 Maximum limitation of the return temperature

Refer to section 27.2.3 "Maximum limitation in d.h.w. heating mode".

18.2 Mode of operation

Conditions for activation of the legionella function:
• The storage tank temperature is acquired with 1 or 2 sensors (legionella function can-
not be provided when using thermostats)
• The legionella function has been parameterized (operating line 104)
• D.h.w. heating is switched on (button
• The holiday function is not active
If the criteria "Set day" and "Time" are met, the legionella function will be released.
Release of the legionella function causes the d.h.w. temperature setpoint to be raised
to the level of the legionella setpoint and to forced charging. If d.h.w. heating is swit-
ched off or the holiday function is active, the legionella function will be released. On
completion of the overriding function, d.h.w. charging to the legionella setpoint will be
triggered since the legionella function continues to be released.
The behavior of the legionella function as a function of the d.h.w. temperature is as
follows:
Basic Documentation RVD230
18 Function block Extra legionella functions
), the legionella function will be
- - -
is lit)
75/130
CE1P2383en
27.05.2004