2.0 Installation
2.1 Before you start
The A333 application key contains 3 subtypes:
A333.1, A333.2
and A333.3
which are almost identical.
Different and extra functions are described additionally.
The application A333.1 is very flexible.
These are the basic principles:
Typically, the flow temperature is adjusted according to your
requirements.
The flow temperature sensor S3 is the most important sensor. The
desired flow temperature at S3 is calculated in the ECL controller,
based on the outdoor temperature (S1) and the desired room
temperature. The lower the outdoor temperature, the higher the
desired flow temperature.
By means of a week schedule (up to 3 'Comfort' periods / day), the
heating circuit can be in 'Comfort' or 'Saving' mode (two different
temperature values for the desired room temperature).
In Saving mode the heating can be reduced or switched off totally.
The motorized control valve M1 is opened gradually when the flow
temperature S3 is lower than the desired flow temperature and
vice versa.
The return temperature (S5) can be limited, for example not to be
too high. If so, the desired flow temperature at S3 can be adjusted
(typically to a lower value), thus resulting in a gradual closing of
the motorized control valve. Furthermore, the return temperature
limitation can be dependent on the outdoor temperature.
Typically, the lower the outdoor temperature, the higher the
accepted return temperature.
In boiler-based heating supply the return temperature should not
be too low (same adjustment procedure as above).
A connected flow or energy meter based on M-bus signal can
limit the flow or energy to a set maximum value. Furthermore the
limitation can be in relation to the outdoor temperature. Typically,
the lower the outdoor temperature, the higher the accepted flow /
power.
The circulation pumps P1 and P2 are operated alternately. One
circulation pump is used as working pump and the other circulation
pump is used as spare pump. The circulation pump in question is
ON at heat demand or at frost protection. The alternation time
can be set as a number of days and a set time on the shift day. A
solution with a single circulation pump can also be selected.
By means of the pressure difference between S9 and S10 the
ECL controller verifies that the circulation pump in question is
operating.
The pressure difference on the secondary side is based on the static
pressures at S9 and S10. The pressures are measured as 0 - 10 volt
signals (from pressure transmitters) and converted (scaled) in the
ECL controller to appropriate pressure values.
Application A333.1:
The shown diagram is a fundamental and simplified example and does
not contain all components that are necessary in a system.
All named components are connected to the ECL Comfort controller.
List of components:
ECL 310 Electronic controller ECL Comfort 310
S1 Outdoor temperature sensor
S2 (Optional) Primary supply temperature sensor. For
monitoring purpose
S3 Secondary flow temperature sensor
S4 (Optional) Secondary return temperature sensor. For
monitoring purpose
S5 (Optional) Primary return temperature sensor
S7 (Optional) Primary supply pressure sensor. For monitoring
purpose
S8 (Optional) Primary return pressure sensor. For monitoring
purpose
S9 Secondary flow pressure sensor
S10 Secondary return pressure sensor
M1 Motorized control valve (3-point controlled)
P1/P2 Circulation pumps
P3/P4 Refill water pumps
V1 Refill water valve
V2 Pressure release valve
A1 Alarm
VI.GU.T2.02
© Danfoss | 2017.09 | 5
Operating Guide ECL Comfort 310, application A333
