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Building Technologies
Boiler sequence controller RMK770
CE1P3132en
HVAC Products
5 General functions, fundamentals
23.04.2009
Main menu > Commissioning > Settings > …
or
Main menu > Settings > Boiler sequence manager > Twin pump
Main menu > Settings > Boiler … > Twin pump
Main menu > Settings > Primary controller > Twin pump
Main menu > Settings > Heating circuit > Twin pump
Operating line
Range
Factory setting
Run priority
Auto / Twin pump A /
Twin pump B
Auto
Changeover period
–60…0…+60 s
0 s
5.8.3 Changeover
logic
For pump changeover, there are 3 choices available:
•
Automatic changeover once a week; should the working pump become faulty,
changeover to the second pump takes place.
When switching on the next time, the pump that starts to run is always the pump that
was in operation last
•
Pump A is always the working pump; in the event of fault, changeover to pump B
takes place. After rectification of the fault, changeover back to pump A takes place
•
Pump B is always the working pump.
In the event of fault, changeover to pump A takes place. After rectification of the
fault, changeover back to pump B takes place
The changeover time is the same time as that used for the pump / mixing valve kick
(kick day and kick time).
For this reason, this setting must be checked.
Automatic changeover takes place on completion of 168 hours (7 days) or – after a new
plant start – when the kick day and kick time are reached.
Even if the pump kick is deactivated, both kick time and kick day remain defined.
Changeover from one pump to the other can take place as follows, depending on the
application:
•
With no interruption
•
With overlapping
•
With interruption
The changeover from pump A to pump B takes place at the same time:
31
31
D
42
A
B
The changeover from pump A to pump B overlaps, e.g. to ensure a low noise level
during changeover. The pump to be deactivated overruns for the adjusted period of
time.
31
31
D
43
A
B
The changeover from pump A to pump B is made after a certain pause, e.g. to prevent
voltage peaks or excessive water pressures.
31
31
D
44
A
B
Setting
Run priority
Changeover time
Changeover period
No changeover
delay
Changeover with
negative delay
Changeover with
positive delay