5.9 Pump control
The A333 application can operate with one or two circulation
pumps, P1 or P1 / P2.
When operating with two circulation pumps, the pumps are
controlled alternately, according to a time set-up.
When a pump is switched ON the controller is waiting for pressure
difference (S9 - S10) to build up.
If an acceptable pressure difference is not achieved, an alarm is
generated and the ECL Comfort controller switches ON the other
pump.
If none of the pumps can come into operation (detected by means
of an unacceptable pressure difference), the alarm is activated and
the motorized control valve M1 closes (a safety function).
The alarm function is disabled if the "Alarm handling" (ID no. 11316) is
set to OFF.
Settings for pressure transmitter signal (0 - 10 volt) and conversion into
pressure value are described in the section S7, S8, S9, S10 pressure.
MENU > Settings > Pump control
Pressure diff.
11322
Circuit
Setting range
Factory setting
1
0.1 . . . 5.0 bar
1.5 bar
Setting of acceptable pressure difference between S9 and S10 in order to
feed back that the circulation pump is working properly.
0.1 - 5.0:
Set the desired pressure difference between S9 and S10
(in bar)
MENU > Settings > Pump control
Chan.-over time (change-over time)
11314
Circuit
Setting range
Factory setting
1
OFF / 1 ... 99 s
15 sec
Setting of time to elapse between the pump stop command for one pump
and the start command for the other pump.
The change-over time can ensure that a pump is stopped efficiently before
the other pump starts.
OFF:
One circulation pump in the application.
1 ... 99:
Time for change-over.
X
= Time
# 1 # = Change-over time (sec.)
100 | © Danfoss | 2017.09
VI.GU.T2.02
Operating Guide ECL Comfort 310, application A333
