6.11.11 Circulation pump control for the HRU
In systems with connected heat recovery unit (Anl 3, Anl 5 and Anl 9) the binary output BA5
controls the HRU pump. This pump is only activated when the control signal is Y2 > 0 %. If
Y2 is 0 % for longer than three minutes when the system is in operation, the circulation pump
is deactivated. First when Y2 > 0 % it is activated again. If the time-of-use ends, the HRU
pump is deactivated after three minutes.
The HRU pump is activated at least once for approximately one minute every 24 hours to
prevent it from becoming jammed up.
6.11.12 Electric air heater
The binary output BA5 can also be used to control an electric air heater in on/off operation
instead of the HRU pump. BA5 is then controlled depending on the control signal Y1.
The control signal Y1 is available parallely!
Function
WE
Configuration
BA5 dependent on Y1
OFF
30 %
10 %
10 sec
FB38 = ON
START (activating value) / STOP up to 100 %
STOP (deactivating value) / 0 % up to START
Lag time of the fans / 0 to 60 sec
EB 5477 EN
67
Control functions