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Siemens Building Technologies
Basic Documentation RVP540 / RVP550
CE1P2488en
HVAC Products
Description of the heating engineer settings
18.10.2002
4.236 Legionella function strategy
•
Potential legionella bacteria in the d.h.w. storage tank will be killed at regular inter-
vals.
•
Strategy can be selected
The legionella function ensures that the d.h.w. in the storage tank will periodically be
raised to the temperature level adjusted on operating line 792 (legionella setpoint), thus
making certain that potential legionella bacteria will be killed.
The legionella setpoint must be maintained for the period of time set on operating line
794.
Setting range
Unit
Factory setting
1...3 –
1
Entry:
1
Maximum period
The legionella function will be triggered no later than after an
adjustable num-
ber of days since the last time the temperature dropped below the legion-
ella setpoint
.
If the legionella setpoint (operating line 792) is reached during the
last 3 days
of
the set “maximum period” (since 00:00 of the last day but 2) through wood-firing
or solar energy, the legionella function will be omitted and the “Maximum period”
starts again.
If the legionella setpoint was not reached during the last 3 days of the “Maximum
period”, one of the controllable heat sources will be put into operation to ensure
the legionella setpoint will be attained.
2
Fixed period
The legionella function will be triggered after an
adjustable number of days
(1...7 days, refer to operating line 790). If the legionella setpoint (operating line
792) has already been reached
on the same day
(due to heating by noncon-
trollable heat sources), the legionella function will be omitted and reactivated
only after the selected number of days have elapsed again.
3
Fixed weekday
The legionella function will be triggered on a
fixed weekday
(1=Mo through
7=Su,
refer to operating line 790). If the legionella setpoint (operating line 792) has al-
ready been reached
on the same day
(due to heating by noncontrollable heat
sources), the legionella function will be omitted and reactivated only a week
later.
The legionella function is started in the respective mode, depending on the settings
made on this and the previous operating lines. The d.h.w. is heated up to the adjusted
setpoint of the legionella function. The function will be maintained for a maximum pe-
riod of 40 hours, that is, during this period of time, the controller attempts during d.h.w.
nominal setpoint phases to bring the d.h.w. storage tank temperature to the legionella
setpoint. During the d.h.w. reduced setpoint phase, the legionella function is not active.
This function is possible only when d.h.w. heating is released by the d.h.w. heating
program.
If the legionella setpoint is not reached within 40 hours, an error message appears on
operating line 50 and the legionella function will be repeated on the next selected date.
Benefit
Description
Setting
Effect
Notes
