Dhw Heating With Mcm10 Cascade Systems; Internal Frost Protection Function; Control Of One Heating Circuit Pump; External Switching Contact - Buderus MCM10 Instrucciones De Instalación

Subject to the heating controller used, a cascade system
with either up to 4 or up to 16 boilers can be created. The
maximum number of boilers that can be connected and
the number of MCM10 modules required for the different
system versions are shown in table 6, page 62.
The different system versions require the
connection of certain accessories: flow
temperature sensor, outside temperature
sensor, heating circuit pump and heating
controller ( tab. 6, page 62).
The MCM10 module regulates the entire heat generation
circuit (primary circuit up to and including the low loss
header). All other heating system components (secondary
side of the low loss header, such as the heating circuits,
DHW cylinder) can be regulated by a weather-
compensated heating controller with EMS BUS interface
and additional modules (WM10, MM10, ...). Contact the
manufacturer for further details. You will find the address
on the back cover.
Boilers of any output size can be linked into the cascade.
2.7.3

DHW heating with MCM10 cascade systems

DHW cylinders can be connected electrically and
hydraulically direct to a boiler (cylinder version).
• DHW heating is regulated by the boiler. During active
DHW heating, the relevant boiler will not be controlled
by the MCM10 module. A different boiler may be
started if there is a heat demand.
• If DHW heating is to be implemented under time
control in a heating system with heating controller with
EMS BUS control, then the boiler to which the DHW
cylinder is connected must be connected to terminals
17 and 18 of the MCM10 master module.
If the user wishes to heat hot water via the
boiler 3-way valve and at the same time
supply the heating circuits, DHW priority
must be disabled on the RC35 programming
unit of all heating circuits, as the standard
setting enables DHW priority.
2.7.4

Internal frost protection function

The MCM10 module is equipped with an internal frost
protection function: if the flow temperature falls below
7 °C, a boiler starts and runs until a flow temperature of
15 °C has been achieved. The supply pump that may be
connected to the MCM10 module will then also run
( chapter 2.7.5).
B Connect the flow temperature sensor to the MCM10
master module if internal frost protection is to be
applied.
MCM10
Details about the MCM10 module
The frost protection function of one heating
controller with 2-wire BUS interface provides
comprehensive system frost protection. This
requires the connection of an outside
temperature sensor.
2.7.5

Control of one heating circuit pump

The heating circuit pump can be connected directly to the
MCM10 master module in heating systems with only 1
heating circuit. When an RC35 programming unit is being
used in the system, the heating circuit pump must be
connected to the WM10 low loss header module.
The heating circuit pump runs as long as at least one
boiler pump is running (if required, set the pump run-on
time on the boiler according to the boiler installation
instructions).
The pump kick lets the heating circuit pump
run once every day even without a heat
demand (e.g. during summer).
B Leave your heating system switched on all
year to prevent the pumps (in summer)
from seizing up.
2.7.6

External switching contact

The MCM10 module is equipped with an external
switching contact ( fig. 3, [G], page 59). Parameters
for this switch ( tab. 3, page 60).
This external switching contact can be used, for example
for connecting a temperature limiter to protect an
underfloor heating system against excessively high
heating water temperatures.
All boilers are shut down when the switching contact is
open. The boilers are ready for use when the switching
contact is closed.
2.7.7

System versions overview

As a manufacturer of advanced heating technology, we
give high priority to the development and manufacture of
economical and efficient boilers. To safeguard this
priority, our boilers are equipped with modulating burners.
To make optimum use of the burner characteristics, use
heating controllers with EMS BUS control.
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