Danfoss ECL Comfort C25, User Manual

Page: 46 / 69

The grey
side of the
ECL Card
Ex
tended ser
vic
e
Service parameter(s) 30-35
32h
30 Return temperature limitation
Circuit Setting range Factory setting
I 10 ... 110 °C 40 °C
Set the return temperature you accept for the heating / DHW
circuit.
Set the acceptable return temperature limit.
When the return temperature falls below or gets higher
than the set value, the controller automatically changes the
desired flow temperature to obtain an acceptable return
temperature. The influence is set in lines 35 and 36.
For some applications the return temperature limitation for
heating circuits is set in lines 31-34 (outdoor temperature
dependent limitation).
35 Return temperature influence - max. limitation
Circuit Setting range Factory setting
I -9.9 ... 0 ... 9.9 0.0
Set the influence from the return temperature on the desired flow
temperature.
Set the influence of the max. return temperature
limitation (set in line 30 or lines 31-34).
Influence higher than 0:
The desired flow temperature is increased, when
the return temperature gets higher than the set
limit.
Influence lower than 0:
The desired flow temperature is decreased, when
the return temperature gets higher than the set
limit.
0
Influence
Max. limitation > 0
Return limit
Return temp.
Max. limitation < 0
Example
The return limit is active from 50 °C.
The influence is set to -2.0.
The actual return temperature is 2 degrees too high.
Result:
The desired flow temperature is changed by -2.0 x 2 = -4 degrees.
Normally, the setting in line 35 is lower than 0 in district heating
systems to avoid a too high return temperature.
Typically, the setting in line 35 is 0 in boiler systems because a
higher return temperature is acceptable (see also line 36).