Siemens QAA73.210 User Manual page 28

Maximum DHW
temperature setpoint
(HW MX)
Note
Minimum DHW
temperature setpoint
(HW MN)
Note
Legionella function
(L FCT)
Notes
Dwelling time at
legionella function
setpoint (L TIME)
Setpoint of the
legionella function
(L TEMP)
28 / 36
Siemens
Building Technologies
· Function for limiting the maximum settable nominal setpoint of the d.h.w.
temperature.
A d.h.w. setpoint maximum (TBWmax) of a BMU transmitted via OpenTherm is
given priority and replaces that of the room unit (setting 130).
· Function for limiting the minimum settable nominal setpoint of the d.h.w.
temperature.
A d.h.w. setpoint minimum (TBWmin) of a BMU transmitted via OpenTherm is
given priority and replaces that of the room unit (setting 130).
The legionella function ensures that the d.h.w. in the storage tank will periodically
be raised to a temperature higher than nominal setpoint.
The setting activates or deactivates the legionella function. Entry:
OFF Function inactive
Weekly ON: Function is activated every Monday morning when d.h.w. is heated
up for the first time and lasts a maximum of 2.5 hours. The d.h.w. is
heated up to the adjusted legionella setpoint.
Daily Function is activated every day when d.h.w. is heated up for the first
time and lasts a maximum of 2.5 hours. The d.h.w. is heated up to the
adjusted legionella setpoint.
· If on the starting day of the legionella function, d.h.w. is not heated, or if the
function is aborted, it will be repeated the next day when d.h.w. is heated for the
first time.
· This function is possible only when d.h.w. heating is released by the d.h.w.
heating program.
The setpoint of the legionella function (operating line 92) is maintained for at least
the period of time set here.
--- Function deactivated (no dwelling time)
The dwelling time starts as soon as the legionella setpoint is reached.
During the entire dwelling time, the temperature may not fall below the legionella
setpoint by more than the set BMU d.h.w. switching differential. The legionella
function is terminated when this criterion is met.
The setpoint of the legionella function is an adjustable temperature level to which
the d.h.w. temperature is raised when the legionella function is activated.
The setting changes the d.h.w. setpoint during the period of time the d.h.w. is
heated up as a result of the legionella function.
Room Unit for Boiler Control
Description of room unit settings
CE1U2283en
2015-09-16