Construction And Function - oventrop Regumaq K Notice D'installation Et D'utilisation

On system example 4.6,
"Regumaq X" with external circulation pump
The system example 4.6 with external circulation pump
shows the pipework set 1381080 in the fresh water
stations.
The set includes a prefabricated T-piece with check
valve, a ball valve with integrated thermometer as well
as seals and an insulation screen for a time-saving
integration into the fresh water stations "Regumaq X".
The external circulation pump is activated by one
controller "Regtronic RQ".
All settings must be carried out at all controllers of the
cascade. If the pipework set is not used, the circulation
return of the external circulation pump has to be
divided between the individual fresh water stations
"Regumaq X-30" and be connected to the cold water
supply between the ball valve and the station with a
check valve and a T-piece.
Important:
All connection options call for a limitation of the external
circulation pump to a maximum output of 25 l/min. per
fresh water station

5 Construction and function

5.1 Summary and functional description
In hot water supply systems, the required discharge
capacity may exceed the nominal capacity of a single
fresh water station. In this case, several fresh water
stations are connected into one cascade.
Depending on the withdrawal quantity, the cascade
control set serves the distribution of the cold water to
the fresh water stations according to requirements.
Due to the construction, a constant hot water
temperature is guaranteed even if the withdrawal
quantities fluctuate as the individual stations are
primarily operated at medium or high capacity.
The maximum discharge capacity of the complete
system is determined by the sum of the performances
of the individual stations and their operating
parameters.
5.2 Mode of operation
Fresh water stations installed in parallel are activated
or inactivated via motor-operated ball valves according
to requirements. At least one of the ball valves with
actuators installed in the supply pipe is always open.
It is referred to as "primary actuator" and changes
daily to ensure a balanced utilisation of all fresh water
stations. The remaining actuators which are idle when
the system is not in operation are referred to as
"secondary actuators".
The individual actuators communicate via a bus
system. The flow sensor VFS 10-200 installed in the
cold water supply pipe constantly measures the
withdrawal quantity and passes the information on to
the master actuator marked "1" in the cascade control
system. All actuators in the system are controlled by
the master actuator.
The slave actuators are marked "2", "3" and "4".
If the withdrawal quantity exceeds a fixed preset value,
the master actuator sends a switching command via
the bus. Now a secondary actuator opens in addition
to the primary actuator. If the withdrawal quantity
increases, further secondary actuators are activated
successively. If the withdrawal quantity decreases, the
stations are deactivated in the reverse order by closing
the ball valves.
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The actuators react to changes in the withdrawal
quantities with a delay of a few seconds.
The actuators of the cascade control and the
controllers of the fresh water stations are autonomous.
5.3 Optional additional functions:
– Emergency operation:
Each actuator (master and slave) can be opened and
closed manually after having pressed the manual
override button (see paragraph 6.3). This status is
recognized by the cascade control and it adapts to
the new operating status. By isolating a fresh water
station with the manual override button engaged, a
cascade with four stations for instance becomes a
cascade with three stations.
The remaining stations continue to work as usual.
This way, maintenance is simplified and operational
safety is increased.
– Temperature guided return layering:
Activation of a three-way valve for return layering
can be carried out with the help of the programmed
optional function "Return layering" of the controller
"Regtronic RQ".
Two additional temperature sensors are required for
this optional function which serves the control of the
valve dependent on the temperature difference
between the return pipe and the central storage
cylinder section.
Suitable components: see chapter 13 "Accessories
and spare parts"
With the "accessories set switching module"
– Temperature dependent return layering:
During circulation operation with no water being drawn
off, the return flow water of the storage cylinder can
be fed into the central storage cylinder section with
the help of a diverting valve with actuator.
As the return temperature during circulation operation
is higher than during hot water operation, temperature
layering of the buffer storage cylinder is optimised.
– Fault monitoring:
If the temperature sensor included in the accessories
set switching module does not reach a minimum water
temperature in the common hot water pipe within a
specific time after having started to draw off water, the
switching module closes two volt free contacts. A fault
message can be sent to the centralised building control
system or a signalling unit via these contacts.
Suitable components: see chapter 13 "Accessories
and spare parts"
5.4 Advice regarding planning and design
The fresh water cascade is part of a potable water
supply system to be planned on an individual basis.
To guarantee a secure and hygienically safe operation,
all components of the potable water installation, e.g.
heat generator, buffer storage cylinder, hydraulically
balanced pipework etc. and their functions, e.g. an
adequate buffer storage cylinder temperature, a
potable water temperature ≥ 55 °C, must be taken into
consideration during planning and design.
You can find more detailed information in chapter 4
"Technical data".