Forced Operation Of The Pumps; Return Flow Temperature Limitation - Samson TROVIS 5579 Mounting And Operating Instructions

System-wide functions
7.3

Forced operation of the pumps

When the heating circuit pumps have not been activated for 24 hours, forced operation of
the pumps is started between 12.02h and 12.03h. This is done to avoid that the pumps get
stuck when they are not operated for a longer period of time. In the DHW circuit, the circula-
tion pump is operated between 12.04h and 12.05h, the other pumps between 12.05h and
12.06h.
7.4

Return flow temperature limitation

The temperature difference between the flow and return flow indicates how well the energy is
used: the greater the difference, the higher the efficiency. A return flow sensor is sufficient to
evaluate the temperature difference when the flow temperatures are preset. The return flow
temperature can be limited either to a value depending on the outdoor temperature (vari-
able) or to a fixed set point. When the temperature measured at return flow sensor RüF ex-
ceeds the limit value, the set point of the flow temperature (flow temperature of the heating
system, charging temperature) is reduced. As a result, the primary flow rate is reduced and
the return flow temperature falls.
In systems Anl 2.x, 3.1-3.4, 4.1-4.3, 5.1, 5.2, 7.x, 8.x and 9.x, the Max. return flow tem-
perature parameter (PA4 level) is used for limitation in the primary circuit during DHW heat-
ing if it is greater than the parameter valid for the primary circuit. In systems Anl 7.x, 8.x
and 9.x with additional return flow sensor RüF2, a Max. return flow temperature parameter
that is set to a lower limit (PA4 level) only leads to a limitation in the DHW circuit at first; the
return flow temperature limitation in the primary circuit only starts when the higher return
flow temperature limit valid for that circuit is exceeded. The Limiting factor determines how
strongly the controller responds when the limit values are exceeded in either direction (PI al-
gorithm).
If just proportional component is to be implemented, set CO5 -> F16 - 1. This allows the inte-
gral-action component in the return flow temperature limitation algorithm of all control cir-
cuits of the controller to be deactivated.
The set point reading (flow temperature of the heating, charging temperature) blinks to indi-
cate that a return flow limitation is active in the control circuit concerned.
Note: Using weather-compensated control with gradient characteristic, the return flow tem-
perature is limited to a fixed value by equating the Return flow temperature foot and Max.
return flow temperature (PA1, 2, 3) parameters.
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EB 5579 EN