Basic Documentation

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Siemens Modular Heating Controller RMH760B CE1P3133en
Building Technologies 10 DHW heating 2017-09-29
The circulating pump can be operated according to the time switch or, using this
setting, can be made to run constantly (24-hour operation). This setting will be
overridden when preselecting "Off" with the DHW operating mode, which means that
the circulating pump will also be deactivated.
The circulating pump can be operated according to its time switch or the DHW time
switch. This setting will be active only if "Operation circulating pump" is set to "Time
switch".
In interval operation, the circulating pump runs for 10 minutes at 30-minute intervals
(every full and every half hour), resulting in off times of 20 minutes. The pump runs only
when enabled according to the time switch or parameterization. When enabling is
started, the pump always runs for 10 minutes, independent of the time of day. But this
does not apply when turning on power or when leaving commissioning.
Some of the functions require a circulating pump, such as the legionella function in
connection with consumer control or direct DHW heating. If a circulating pump is in
operation that is independent of the controller, this can be communicated to the
controller by making use of this setting.
Main menu > Commissioning > Settings > … or
Main menu > Settings > DHW > Legionella function
Operating line
Range
Factory setting
Circulating pump operation legio
Time switch / On
On
To include the circulating pump in the legionella function, this setting can be used to
activate the pump for the period of time the legionella function is performed. When using
setting Time switch, the legionella function has no influence on the circulating pump.
10.11.4 Electric immersion heater
With the exception of DHW plant type DHW 0, which uses exclusively an electric
immersion heater, all DHW plant types with storage tank can be switched to electric
immersion heater during summer operation. Operation with an electric immersion
heater is identical to space heating mode with the same DHW operating modes,
setpoints, legionella function, etc.
Only DHW plant type DHW 0 can operate without a storage tank sensor. In that case,
only the electric immersion heater will be enabled.
Changeover to summer operation takes place depending on the heating circuits’ heat
demand. If the heating circuits do not call for heat for a period of 72 hours, changeover
to summer operation will take place at midnight after the 72 hours have elapsed.
The electric immersion heater receives the release signal and storage tank charging
with hot water will be switched off.
Frost protection for the storage tank will still be ensured (also refer to subsection 10.8.3
"Frost protection functions").
As soon as one of the heating circuits calls for heat, there will be a change to winter
operation with hot water.
If the heat source reports a fault (e.g. due to a malfunction or user intervention), the
electric immersion heater will be enabled and storage tank charging with hot water
switched off. For this function to be performed, heat source and DHW heating must be
included in a system network. For more detailed information about function block
"Meter", refer to chapter 15 "Communication".
The output is to be activated via "Extra configuration":
Operation of circulating
pump
Time switch for the
circulating pump
Interval operation of
circulating pump
External circulating
pump
Operation of circulating
pump when legionella
function is activated
Plant types
Changeover to summer
operation
⇒
Changeover in the event
the heat source fails
Extra configuration