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4.4.2 Tmin recirculation = Minimum recirculation temperature at sensor S1
Provided recirculation is enabled, if temperature drops below Tmin recirculation, the pump is switched on.
Settings range: 10 °C to 85 °C
4.4.3 Recirculation hysteresis = Deactivates recirculation pump switching hysteresis
If temperature exceeds Tmin at S1, the pump is switched off.
Settings range: 1-20K / Default: see table.
4.4.4 Maximum recirculation flow = Maximum delivery of recirculation pump
If the flow rate measured at sensor 6 exceeds this value, the recirculation pump is switched off.
Settings range: 1-50 l/min.
b
This value is set during system calibration.
4.4.5 Recirculation periods = The time bands during which the recirculation pump is enabled
Three separate time bands can be set for each day of the week. Bands can be copied from one day to another. Settings
range: Off/ 00:00-23:59 / Default: see table.
b
Recirculation is disabled outside these time bands. The time settings are only used in “Periods” recirculation mode.
4.4.6 Draw-off support
To ensure a constant temperature even when small volumes of water are drawn off, the recirculation pump can also be
used to assist draw-off.
The pump runs under normal conditions and when small volumes are drawn off.
If a storage cylinder sensor is connected, draw-off support is enabled when this sensor detects Tmin.
Settings range: On, Off / Default: see table.
4.4.7 Minimum storage temperature
Draw-off support is disabled if storage temperature drops below “Minimum storage temperature”.
Minimum storage temperature: Settings range: 0 to 80 °C / Default: see table.
4.4.8 Draw-off support measuring
See “F3. - Calibration”.
4.6 Storage stratification
The storage stratification function operates a valve that deviates the return to the centre or bottom of the storage cylinder
on the basis of temperature. This menu sets the temperature differential between the return and the storage cylinder. If
return temperature exceeds storage temperature by the value set here, the central part of the storage cylinder is buffered.
If no storage sensor is connected, storage temperature is set at 25 °C.
4.11 Comfort
When this function is active, the primary circuit pump pumps water through the heat exchanger every 15 minutes to en-
sure that hot water is delivered as rapidly as possible when water is drawn off.
5. PROTECTIVE FUNCTIONS
Menu “5. - Protective functions” can be used to set and
activate a number of protective functions.
To quit the menu, press “esc” or select “Exit Protective
functions”.
5.1 Anti-legionella
With the AL function activated, the MFWC controller heats
the pipes and the storage cylinder at selectable periods
(AL period) for a set time (AL residence time), until the
target temperature setpoint (AL Tset) is reached.
AL Tset + 5 °C is taken as the reference for the temperature measured at S4. For the period during which the AL function
is active, Tmax is set at AL Tset + 10 °C to prevent shut-down for high temperature. The AL function terminates only when
a temperature of at least “AL Tset - 5 °C” is reached at the hot water sensor and at the recirculation sensor (if installed) for
the time set in “AL residence time”. The “Last AL heat” is shown on the display. If the AL function fails to terminate after 2
hours, the function is cancelled and an error message is displayed.
AL function – Settings range: On, Off / Default: see table.
AL run time
AL Tset
AL Period
AL residence time
Manual start – starts a heating cycle immediately
b
During the Anti-legionella function the storage cylinder is heated to high temperatures that can lead to scalding and
damage to the system.
5.Exit protective functions
5.1.Anti-legionella
5.2.Limescale protection
esc
Info
Summary of Contents for MODEX ACS 40 E
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