Rotex Controller Series User Manual

EbV Product documentation THETA NORM/UNIT
8-15
8.1.15.3 Indirect return control
Function: Indirect return control is realized by means of the mixer valves in the heating circuits.
It only works for heating systems without a bypass pump and without controlled flow
mixing.
When this function is active, two values are calculated independently for regulating
each mixing circuit. The first value is the control variable for the flow setpoint of the
heating circuit; the second is the control variable for the return setpoint.
The control variable used for mixer control (mixer control variable) results from the
superimposition of both values. In this the adjustment of the return temperature is
treated with priority.
Indirect return control is only active with mixing circuits that are in heating operation
as well. It does not affect a heating circuit in reduced operation.
To avoid excessive pulsing, we recommend enabling the connected consumers
(heating and DHW circuits) with delayed switch-on times.
This function does not affect direct heating circuits.
NOTE: Even if no return flow sensor is connected, a parameterised return flow temperature
is transferred to the heat generator as a demand.
8.1.16 When to activate boiler sensor 2
Function: A second heat generator can be connected to a variable input (VI1-VI3) optionally.
This is necessary:
• When using two single stage heat generators
The second heat generator is required for monitoring the temperature in the
second heat generator with two boilers or in two single stage heat generators (see
heat generator parameters "Heat generator type").
• When using two measuring points in the combustion chamber
In order to reduce standby losses by increasing the burner running times. The
measured value of the warmer sensor (BS-1 or BS-2) is used as the trigger for
switching on the heat generator. Charging stops according to the measured value
of the colder sensor. The set heat generator parameters are still active.
Operation:
Note on operation Key / parameter tree Parameter
Setting indirect return temperature
control
HYDRAULIC PARAMETER 11
Boiler return control RETURN CONTR PARAMETER 01
Pre-run time boiler circuit pump RETURN CONTR PARAMETER 02
Extended run time boiler circuit pump RETURN CONTR PARAMETER 03
Operation:
Note on operation Key / parameter tree Parameter
Activation heat generator 2 HYDRAULIC PARAMETER 08
PARAMETER 09
PARAMETER 10

Rotex Controller Series Specifications

General

Brand	Rotex
Model	Controller Series
Category	Controller
Language	English