Bypass Pump; Return Control Through Controlled Flow Mixing - Rotex Controller Series Product Documentation

EbV
8.1.15.1 Bypass pump (..VV..)
Function: The return control with a bypass pump (RBP) represents a simple method for a return
temperature control.
If the return temperature of the heat generator falls below the set return low limit the
bypass pump, which is installed parallel to the heat generator, is switched on for flow
temperature addition.
If the return temperature increases above the setpoint plus switching differ-ential, the
bypass pump will be switched off after the time delay (extended run time) has
elapsed. Because the mixing is not controlled, the diameters of the bypasses should
be considered during construction.
NOTE: In order to avoid frequent switching of the bypass pump, the sensor should be
mounted on the consumer side of the mixing point.
Operation:
8.1.15.2

Return control through controlled flow mixing (..3..)

Function: If the control unit is equipped with a mixer output, this output can be programmed for
controlled flow mixing.
In this mode of return control the programmed mixing circuit adjusts the return
temperature to the return temperature setpoint. The return sensor for this function is
connected at the sensor input of the respective mixing circuit (e.g. VF 1 for mixed
circuit 1).
The mixing circuit operates like a boiler circuit pump without boiler start-up protection
for this purpose (see Page 8-12).
Operation:
8-14
Note on operation
Setting bypass pump
Boiler return control
Switch-off differential
Extended run time (pump)
Note on operation
Setting controlled flow mixing
Boiler return control
Pre-run time boiler circuit pump
Extended run time boiler circuit pump
Product documentation THETA NORM/UNIT
Key / parameter tree
HYDRAULIC
RETURN CONTR
RETURN CONTR
RETURN CONTR
Key / parameter tree
HYDRAULIC
RETURN CONTR
RETURN CONTR
RETURN CONTR
Parameter
PARAMETER 06
PARAMETER 07
PARAMETER 01
PARAMETER 02
PARAMETER 03
Parameter
PARAMETER 03
PARAMETER 04
PARAMETER 01
PARAMETER 02
PARAMETER 03