Danfoss ECL Comfort 310 Operating Manual page 13

Operating Guide
The basic principles for application P318.10:
Temperature control of DHW
The desired DHW temperature at S3 determines the temperature
control.
The DHW flow temperature sensor S3 and the DHW circulation
return temperature sensor S9 are the most important sensors and
must be connected. If S3 is not connected, the control valve M1 will
close; alternatively, the control pump P1 / V1 will stop. If S9 is not
connected, the DHW circulation pump will operate at 100 %.
Temperature control of the DHW circulation pipe at S9 ensures the
desired temperature by means of speed control of V3.
The motorized control valve M1 is opened gradually when the
DHW flow temperature is lower than the desired DHW temperature
and vice versa.
Alternatively, the control pump P1 / V1 is increased in speed when
the DHW flow temperature is lower than the desired DHW flow
temperature and vice versa.
The return temperature S5 can be limited, for example not to be
too high. If so, the desired DHW temperature at S3 can be adjusted
(typically to a lower value); this results in a gradual closing of the
motorized control valve or, alternatively, a lower speed of the
control pump.
The supply temperature S2 is used to compensate the proportional
band Xp in order to improve the temperature control at different
supply temperatures.
The water flow signal from F1 can be used to override the control
valve in order to optimize the DHW temperature control. This
pro-active functionality compensates for the delay before the flow
temperature sensor S3 measures a change in temperature.
As an option, the desired DHW temperature can be set externally.
A voltage signal (1 - 10 Volt) can be applied to input S12 (ECA 32 /
35). The scale for voltage versus temperature can be set.
An anti-bacteria function for the DHW circuit is available for
activation on selected days of the week. The anti-bacteria function
can be set to include the DHW circulation.
Danfoss District Energy
ECL Comfort 310, application P318
P318.10, ex. a, DHW application with control valve:
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 ECL Comfort 310 controller
ECA 32
Built-in extension module, 0 - 10 V outputs
ECA 35
Built-in extension module, 0 - 10 V outputs and
PWM outputs
S2 Supply temperature sensor
S3 (mandatory) DHW flow temperature sensor
S5 Return temperature sensor
S9
(mandatory) DHW circulation return temperature
sensor
S12 0 - 10 V input for desired temperature at S3
F1
Cold Water meter (pulse signal)
P3
Speed control of charging pump (0 - 10 V or PWM)
P3 DHW circulation pump (ON-OFF controlled)
V3 Speed control of circulation pump (0 - 10 V or
PWM)
M1
Motorized control valve (3-point controlled)
A1
Alarm
VI.JM.Q3.02
DEN-SMT/DK 13